Merge pull request #62 from OpenModLoader/asm

ASM based class translator

40 files changed, 1802 insertions, 1607 deletions

diff --git a/src/main/java/cuchaz/enigma/mapping/ArgumentEntry.java b/src/main/java/cuchaz/enigma/mapping/ArgumentEntry.java
deleted file mode 100644
index 9154cc2..0000000
--- a/src/main/java/cuchaz/enigma/mapping/ArgumentEntry.java
+++ /dev/null
@@ -1,110 +0,0 @@
-/*******************************************************************************
- * Copyright (c) 2015 Jeff Martin.
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Lesser General Public
- * License v3.0 which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/lgpl.html
- * <p>
- * Contributors:
- * Jeff Martin - initial API and implementation
- ******************************************************************************/
-
-package cuchaz.enigma.mapping;
-
-import cuchaz.enigma.utils.Utils;
-
-public class ArgumentEntry implements Entry {
-
-        private BehaviorEntry behaviorEntry;
-        private int index;
-        private String name;
-
-        public ArgumentEntry(BehaviorEntry behaviorEntry, int index, String name) {
-                if (behaviorEntry == null) {
-                        throw new IllegalArgumentException("Behavior cannot be null!");
-                }
-                if (index < 0) {
-                        throw new IllegalArgumentException("Index must be non-negative!");
-                }
-                if (name == null) {
-                        throw new IllegalArgumentException("Argument name cannot be null!");
-                }
-
-                this.behaviorEntry = behaviorEntry;
-                this.index = index;
-                this.name = name;
-        }
-
-        public ArgumentEntry(ArgumentEntry other) {
-                this.behaviorEntry = other.getBehaviorEntry();
-                this.index = other.index;
-                this.name = other.name;
-        }
-
-        public ArgumentEntry(ArgumentEntry other, String newClassName) {
-                this.behaviorEntry = (BehaviorEntry) other.behaviorEntry.cloneToNewClass(new ClassEntry(newClassName));
-                this.index = other.index;
-                this.name = other.name;
-        }
-
-        public ArgumentEntry(ArgumentEntry other, BehaviorEntry entry) {
-                this.behaviorEntry = entry;
-                this.index = other.index;
-                this.name = other.name;
-        }
-
-        public BehaviorEntry getBehaviorEntry() {
-                return this.behaviorEntry;
-        }
-
-        public int getIndex() {
-                return this.index;
-        }
-
-        @Override
-        public String getName() {
-                return this.name;
-        }
-
-        @Override
-        public ClassEntry getClassEntry() {
-                return this.behaviorEntry.getClassEntry();
-        }
-
-        @Override
-        public String getClassName() {
-                return this.behaviorEntry.getClassName();
-        }
-
-        @Override
-        public ArgumentEntry cloneToNewClass(ClassEntry classEntry) {
-                return new ArgumentEntry(this, classEntry.getName());
-        }
-
-        public String getMethodName() {
-                return this.behaviorEntry.getName();
-        }
-
-        public Signature getMethodSignature() {
-                return this.behaviorEntry.getSignature();
-        }
-
-        @Override
-        public int hashCode() {
-                return Utils.combineHashesOrdered(this.behaviorEntry, Integer.valueOf(this.index).hashCode(), this.name.hashCode());
-        }
-
-        @Override
-        public boolean equals(Object other) {
-                return other instanceof ArgumentEntry && equals((ArgumentEntry) other);
-        }
-
-        public boolean equals(ArgumentEntry other) {
-                return this.behaviorEntry.equals(other.behaviorEntry) && this.index == other.index && this.name.equals(other.name);
-        }
-
-        @Override
-        public String toString() {
-                return this.behaviorEntry + "(" + this.index + ":" + this.name + ")";
-        }
-}
diff --git a/src/main/java/cuchaz/enigma/mapping/BehaviorEntry.java b/src/main/java/cuchaz/enigma/mapping/BehaviorEntry.java
deleted file mode 100644
index 04b4ebc..0000000
--- a/src/main/java/cuchaz/enigma/mapping/BehaviorEntry.java
+++ /dev/null
@@ -1,16 +0,0 @@
-/*******************************************************************************
- * Copyright (c) 2015 Jeff Martin.
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Lesser General Public
- * License v3.0 which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/lgpl.html
- * <p>
- * Contributors:
- * Jeff Martin - initial API and implementation
- ******************************************************************************/
-
-package cuchaz.enigma.mapping;
-
-public interface BehaviorEntry extends Entry {
-        Signature getSignature();
-}
diff --git a/src/main/java/cuchaz/enigma/mapping/ClassMapping.java b/src/main/java/cuchaz/enigma/mapping/ClassMapping.java
index 3935de5..8f3f2b2 100644
--- a/src/main/java/cuchaz/enigma/mapping/ClassMapping.java
+++ b/src/main/java/cuchaz/enigma/mapping/ClassMapping.java
@@ -12,6 +12,9 @@
 package cuchaz.enigma.mapping;
 
 import com.google.common.collect.Maps;
+import cuchaz.enigma.mapping.entry.ClassEntry;
+import cuchaz.enigma.mapping.entry.FieldEntry;
+import cuchaz.enigma.mapping.entry.MethodEntry;
 import cuchaz.enigma.throwables.MappingConflict;
 
 import java.util.ArrayList;
@@ -34,7 +37,6 @@ public class ClassMapping implements Comparable<ClassMapping> {
         private Map<String, MethodMapping> methodsByDeobf;
         private boolean isDirty;
         private Mappings.EntryModifier modifier;
-        private boolean deobfInner;
 
         public ClassMapping(String obfFullName) {
                 this(obfFullName, null, Mappings.EntryModifier.UNCHANGED);
@@ -81,6 +83,10 @@ public class ClassMapping implements Comparable<ClassMapping> {
                 return deobfName;
         }
 
+        public String getTranslatedName(TranslationDirection direction) {
+                return direction.choose(deobfName, obfFullName);
+        }
+
         //// INNER CLASSES ////////
 
         public void setDeobfName(String val) {
@@ -191,21 +197,21 @@ public class ClassMapping implements Comparable<ClassMapping> {
                 return fieldsByObf.values();
         }
 
-        public boolean containsObfField(String obfName, Type obfType) {
-                return fieldsByObf.containsKey(getFieldKey(obfName, obfType));
+        public boolean containsObfField(String obfName, TypeDescriptor obfDesc) {
+                return fieldsByObf.containsKey(getFieldKey(obfName, obfDesc));
         }
 
-        public boolean containsDeobfField(String deobfName, Type deobfType) {
-                return fieldsByDeobf.containsKey(getFieldKey(deobfName, deobfType));
+        public boolean containsDeobfField(String deobfName, TypeDescriptor deobfDesc) {
+                return fieldsByDeobf.containsKey(getFieldKey(deobfName, deobfDesc));
         }
 
         public void addFieldMapping(FieldMapping fieldMapping) {
-                String obfKey = getFieldKey(fieldMapping.getObfName(), fieldMapping.getObfType());
+                String obfKey = getFieldKey(fieldMapping.getObfName(), fieldMapping.getObfDesc());
                 if (fieldsByObf.containsKey(obfKey)) {
                         throw new Error("Already have mapping for " + obfFullName + "." + obfKey);
                 }
                 if (fieldMapping.getDeobfName() != null) {
-                        String deobfKey = getFieldKey(fieldMapping.getDeobfName(), fieldMapping.getObfType());
+                        String deobfKey = getFieldKey(fieldMapping.getDeobfName(), fieldMapping.getObfDesc());
                         if (fieldsByDeobf.containsKey(deobfKey)) {
                                 throw new Error("Already have mapping for " + deobfName + "." + deobfKey);
                         }
@@ -218,63 +224,67 @@ public class ClassMapping implements Comparable<ClassMapping> {
         }
 
         public void removeFieldMapping(FieldMapping fieldMapping) {
-                boolean obfWasRemoved = fieldsByObf.remove(getFieldKey(fieldMapping.getObfName(), fieldMapping.getObfType())) != null;
+                boolean obfWasRemoved = fieldsByObf.remove(getFieldKey(fieldMapping.getObfName(), fieldMapping.getObfDesc())) != null;
                 assert (obfWasRemoved);
                 if (fieldMapping.getDeobfName() != null) {
-                        boolean deobfWasRemoved = fieldsByDeobf.remove(getFieldKey(fieldMapping.getDeobfName(), fieldMapping.getObfType())) != null;
+                        boolean deobfWasRemoved = fieldsByDeobf.remove(getFieldKey(fieldMapping.getDeobfName(), fieldMapping.getObfDesc())) != null;
                         assert (deobfWasRemoved);
                 }
                 this.isDirty = true;
         }
 
-        public FieldMapping getFieldByObf(String obfName, Type obfType) {
-                return fieldsByObf.get(getFieldKey(obfName, obfType));
+        public FieldMapping getFieldByObf(String obfName, TypeDescriptor obfDesc) {
+                return fieldsByObf.get(getFieldKey(obfName, obfDesc));
         }
 
-        public FieldMapping getFieldByDeobf(String deobfName, Type obfType) {
-                return fieldsByDeobf.get(getFieldKey(deobfName, obfType));
+        public FieldMapping getFieldByObf(FieldEntry field) {
+                return getFieldByObf(field.getName(), field.getDesc());
         }
 
-        public String getObfFieldName(String deobfName, Type obfType) {
-                FieldMapping fieldMapping = fieldsByDeobf.get(getFieldKey(deobfName, obfType));
+        public FieldMapping getFieldByDeobf(String deobfName, TypeDescriptor obfDesc) {
+                return fieldsByDeobf.get(getFieldKey(deobfName, obfDesc));
+        }
+
+        public String getObfFieldName(String deobfName, TypeDescriptor obfDesc) {
+                FieldMapping fieldMapping = fieldsByDeobf.get(getFieldKey(deobfName, obfDesc));
                 if (fieldMapping != null) {
                         return fieldMapping.getObfName();
                 }
                 return null;
         }
 
-        public String getDeobfFieldName(String obfName, Type obfType) {
-                FieldMapping fieldMapping = fieldsByObf.get(getFieldKey(obfName, obfType));
+        public String getDeobfFieldName(String obfName, TypeDescriptor obfDesc) {
+                FieldMapping fieldMapping = fieldsByObf.get(getFieldKey(obfName, obfDesc));
                 if (fieldMapping != null) {
                         return fieldMapping.getDeobfName();
                 }
                 return null;
         }
 
-        private String getFieldKey(String name, Type type) {
+        private String getFieldKey(String name, TypeDescriptor desc) {
                 if (name == null) {
                         throw new IllegalArgumentException("name cannot be null!");
                 }
-                if (type == null) {
-                        throw new IllegalArgumentException("type cannot be null!");
+                if (desc == null) {
+                        throw new IllegalArgumentException("desc cannot be null!");
                 }
-                return name + ":" + type;
+                return name + ":" + desc;
         }
 
-        public void setFieldName(String obfName, Type obfType, String deobfName) {
+        public void setFieldName(String obfName, TypeDescriptor obfDesc, String deobfName) {
                 assert (deobfName != null);
-                FieldMapping fieldMapping = fieldsByObf.get(getFieldKey(obfName, obfType));
+                FieldMapping fieldMapping = fieldsByObf.get(getFieldKey(obfName, obfDesc));
                 if (fieldMapping == null) {
-                        fieldMapping = new FieldMapping(obfName, obfType, deobfName, Mappings.EntryModifier.UNCHANGED);
-                        boolean obfWasAdded = fieldsByObf.put(getFieldKey(obfName, obfType), fieldMapping) == null;
+                        fieldMapping = new FieldMapping(obfName, obfDesc, deobfName, Mappings.EntryModifier.UNCHANGED);
+                        boolean obfWasAdded = fieldsByObf.put(getFieldKey(obfName, obfDesc), fieldMapping) == null;
                         assert (obfWasAdded);
                 } else {
-                        boolean wasRemoved = fieldsByDeobf.remove(getFieldKey(fieldMapping.getDeobfName(), obfType)) != null;
+                        boolean wasRemoved = fieldsByDeobf.remove(getFieldKey(fieldMapping.getDeobfName(), obfDesc)) != null;
                         assert (wasRemoved);
                 }
                 fieldMapping.setDeobfName(deobfName);
                 if (deobfName != null) {
-                        boolean wasAdded = fieldsByDeobf.put(getFieldKey(deobfName, obfType), fieldMapping) == null;
+                        boolean wasAdded = fieldsByDeobf.put(getFieldKey(deobfName, obfDesc), fieldMapping) == null;
                         assert (wasAdded);
                 }
                 this.isDirty = true;
@@ -282,13 +292,13 @@ public class ClassMapping implements Comparable<ClassMapping> {
 
         //// METHODS ////////
 
-        public void setFieldObfNameAndType(String oldObfName, Type obfType, String newObfName, Type newObfType) {
+        public void setFieldObfNameAndType(String oldObfName, TypeDescriptor obfDesc, String newObfName, TypeDescriptor newObfDesc) {
                 assert (newObfName != null);
-                FieldMapping fieldMapping = fieldsByObf.remove(getFieldKey(oldObfName, obfType));
+                FieldMapping fieldMapping = fieldsByObf.remove(getFieldKey(oldObfName, obfDesc));
                 assert (fieldMapping != null);
                 fieldMapping.setObfName(newObfName);
-                fieldMapping.setObfType(newObfType);
-                boolean obfWasAdded = fieldsByObf.put(getFieldKey(newObfName, newObfType), fieldMapping) == null;
+                fieldMapping.setObfDesc(newObfDesc);
+                boolean obfWasAdded = fieldsByObf.put(getFieldKey(newObfName, newObfDesc), fieldMapping) == null;
                 assert (obfWasAdded);
                 this.isDirty = true;
         }
@@ -298,23 +308,23 @@ public class ClassMapping implements Comparable<ClassMapping> {
                 return methodsByObf.values();
         }
 
-        public boolean containsObfMethod(String obfName, Signature obfSignature) {
-                return methodsByObf.containsKey(getMethodKey(obfName, obfSignature));
+        public boolean containsObfMethod(String obfName, MethodDescriptor obfDescriptor) {
+                return methodsByObf.containsKey(getMethodKey(obfName, obfDescriptor));
         }
 
-        public boolean containsDeobfMethod(String deobfName, Signature obfSignature) {
-                return methodsByDeobf.containsKey(getMethodKey(deobfName, obfSignature));
+        public boolean containsDeobfMethod(String deobfName, MethodDescriptor obfDescriptor) {
+                return methodsByDeobf.containsKey(getMethodKey(deobfName, obfDescriptor));
         }
 
         public void addMethodMapping(MethodMapping methodMapping) {
-                String obfKey = getMethodKey(methodMapping.getObfName(), methodMapping.getObfSignature());
+                String obfKey = getMethodKey(methodMapping.getObfName(), methodMapping.getObfDesc());
                 if (methodsByObf.containsKey(obfKey)) {
                         throw new Error("Already have mapping for " + obfFullName + "." + obfKey);
                 }
                 boolean wasAdded = methodsByObf.put(obfKey, methodMapping) == null;
                 assert (wasAdded);
-                if (methodMapping.getDeobfName() != null) {
-                        String deobfKey = getMethodKey(methodMapping.getDeobfName(), methodMapping.getObfSignature());
+                if (!methodMapping.isObfuscated()) {
+                        String deobfKey = getMethodKey(methodMapping.getDeobfName(), methodMapping.getObfDesc());
                         if (methodsByDeobf.containsKey(deobfKey)) {
                                 throw new Error("Already have mapping for " + deobfName + "." + deobfKey);
                         }
@@ -326,44 +336,48 @@ public class ClassMapping implements Comparable<ClassMapping> {
         }
 
         public void removeMethodMapping(MethodMapping methodMapping) {
-                boolean obfWasRemoved = methodsByObf.remove(getMethodKey(methodMapping.getObfName(), methodMapping.getObfSignature())) != null;
+                boolean obfWasRemoved = methodsByObf.remove(getMethodKey(methodMapping.getObfName(), methodMapping.getObfDesc())) != null;
                 assert (obfWasRemoved);
-                if (methodMapping.getDeobfName() != null) {
-                        boolean deobfWasRemoved = methodsByDeobf.remove(getMethodKey(methodMapping.getDeobfName(), methodMapping.getObfSignature())) != null;
+                if (!methodMapping.isObfuscated()) {
+                        boolean deobfWasRemoved = methodsByDeobf.remove(getMethodKey(methodMapping.getDeobfName(), methodMapping.getObfDesc())) != null;
                         assert (deobfWasRemoved);
                 }
                 this.isDirty = true;
         }
 
-        public MethodMapping getMethodByObf(String obfName, Signature obfSignature) {
-                return methodsByObf.get(getMethodKey(obfName, obfSignature));
+        public MethodMapping getMethodByObf(String obfName, MethodDescriptor obfDescriptor) {
+                return methodsByObf.get(getMethodKey(obfName, obfDescriptor));
+        }
+
+        public MethodMapping getMethodByObf(MethodEntry method) {
+                return getMethodByObf(method.getName(), method.getDesc());
         }
 
-        public MethodMapping getMethodByDeobf(String deobfName, Signature obfSignature) {
-                return methodsByDeobf.get(getMethodKey(deobfName, obfSignature));
+        public MethodMapping getMethodByDeobf(String deobfName, MethodDescriptor obfDescriptor) {
+                return methodsByDeobf.get(getMethodKey(deobfName, obfDescriptor));
         }
 
-        private String getMethodKey(String name, Signature signature) {
+        private String getMethodKey(String name, MethodDescriptor descriptor) {
                 if (name == null) {
                         throw new IllegalArgumentException("name cannot be null!");
                 }
-                if (signature == null) {
-                        throw new IllegalArgumentException("signature cannot be null!");
+                if (descriptor == null) {
+                        throw new IllegalArgumentException("descriptor cannot be null!");
                 }
-                return name + signature;
+                return name + descriptor;
         }
 
-        public void setMethodName(String obfName, Signature obfSignature, String deobfName) {
-                MethodMapping methodMapping = methodsByObf.get(getMethodKey(obfName, obfSignature));
+        public void setMethodName(String obfName, MethodDescriptor obfDescriptor, String deobfName) {
+                MethodMapping methodMapping = methodsByObf.get(getMethodKey(obfName, obfDescriptor));
                 if (methodMapping == null) {
-                        methodMapping = createMethodMapping(obfName, obfSignature);
-                } else if (methodMapping.getDeobfName() != null) {
-                        boolean wasRemoved = methodsByDeobf.remove(getMethodKey(methodMapping.getDeobfName(), methodMapping.getObfSignature())) != null;
+                        methodMapping = createMethodMapping(obfName, obfDescriptor);
+                } else if (!methodMapping.isObfuscated()) {
+                        boolean wasRemoved = methodsByDeobf.remove(getMethodKey(methodMapping.getDeobfName(), methodMapping.getObfDesc())) != null;
                         assert (wasRemoved);
                 }
                 methodMapping.setDeobfName(deobfName);
                 if (deobfName != null) {
-                        boolean wasAdded = methodsByDeobf.put(getMethodKey(deobfName, obfSignature), methodMapping) == null;
+                        boolean wasAdded = methodsByDeobf.put(getMethodKey(deobfName, obfDescriptor), methodMapping) == null;
                         assert (wasAdded);
                 }
                 this.isDirty = true;
@@ -371,35 +385,35 @@ public class ClassMapping implements Comparable<ClassMapping> {
 
         //// ARGUMENTS ////////
 
-        public void setMethodObfNameAndSignature(String oldObfName, Signature obfSignature, String newObfName, Signature newObfSignature) {
+        public void setMethodObfNameAndSignature(String oldObfName, MethodDescriptor obfDescriptor, String newObfName, MethodDescriptor newObfDescriptor) {
                 assert (newObfName != null);
-                MethodMapping methodMapping = methodsByObf.remove(getMethodKey(oldObfName, obfSignature));
+                MethodMapping methodMapping = methodsByObf.remove(getMethodKey(oldObfName, obfDescriptor));
                 assert (methodMapping != null);
                 methodMapping.setObfName(newObfName);
-                methodMapping.setObfSignature(newObfSignature);
-                boolean obfWasAdded = methodsByObf.put(getMethodKey(newObfName, newObfSignature), methodMapping) == null;
+                methodMapping.setObfDescriptor(newObfDescriptor);
+                boolean obfWasAdded = methodsByObf.put(getMethodKey(newObfName, newObfDescriptor), methodMapping) == null;
                 assert (obfWasAdded);
                 this.isDirty = true;
         }
 
-        public void setArgumentName(String obfMethodName, Signature obfMethodSignature, int argumentIndex, String argumentName) {
+        public void setArgumentName(String obfMethodName, MethodDescriptor obfMethodDescriptor, int argumentIndex, String argumentName) {
                 assert (argumentName != null);
-                MethodMapping methodMapping = methodsByObf.get(getMethodKey(obfMethodName, obfMethodSignature));
+                MethodMapping methodMapping = methodsByObf.get(getMethodKey(obfMethodName, obfMethodDescriptor));
                 if (methodMapping == null) {
-                        methodMapping = createMethodMapping(obfMethodName, obfMethodSignature);
+                        methodMapping = createMethodMapping(obfMethodName, obfMethodDescriptor);
                 }
-                methodMapping.setArgumentName(argumentIndex, argumentName);
+                methodMapping.setLocalVariableName(argumentIndex, argumentName);
                 this.isDirty = true;
         }
 
-        public void removeArgumentName(String obfMethodName, Signature obfMethodSignature, int argumentIndex) {
-                methodsByObf.get(getMethodKey(obfMethodName, obfMethodSignature)).removeArgumentName(argumentIndex);
+        public void removeArgumentName(String obfMethodName, MethodDescriptor obfMethodDescriptor, int argumentIndex) {
+                methodsByObf.get(getMethodKey(obfMethodName, obfMethodDescriptor)).removeLocalVariableName(argumentIndex);
                 this.isDirty = true;
         }
 
-        private MethodMapping createMethodMapping(String obfName, Signature obfSignature) {
-                MethodMapping methodMapping = new MethodMapping(obfName, obfSignature);
-                boolean wasAdded = methodsByObf.put(getMethodKey(obfName, obfSignature), methodMapping) == null;
+        private MethodMapping createMethodMapping(String obfName, MethodDescriptor obfDescriptor) {
+                MethodMapping methodMapping = new MethodMapping(obfName, obfDescriptor);
+                boolean wasAdded = methodsByObf.put(getMethodKey(obfName, obfDescriptor), methodMapping) == null;
                 assert (wasAdded);
                 this.isDirty = true;
                 return methodMapping;
@@ -459,24 +473,24 @@ public class ClassMapping implements Comparable<ClassMapping> {
 
                 // rename field types
                 for (FieldMapping fieldMapping : new ArrayList<>(fieldsByObf.values())) {
-                        String oldFieldKey = getFieldKey(fieldMapping.getObfName(), fieldMapping.getObfType());
+                        String oldFieldKey = getFieldKey(fieldMapping.getObfName(), fieldMapping.getObfDesc());
                         if (fieldMapping.renameObfClass(oldObfClassName, newObfClassName)) {
                                 boolean wasRemoved = fieldsByObf.remove(oldFieldKey) != null;
                                 assert (wasRemoved);
                                 boolean wasAdded = fieldsByObf
-                                        .put(getFieldKey(fieldMapping.getObfName(), fieldMapping.getObfType()), fieldMapping) == null;
+                                        .put(getFieldKey(fieldMapping.getObfName(), fieldMapping.getObfDesc()), fieldMapping) == null;
                                 assert (wasAdded);
                         }
                 }
 
                 // rename method signatures
                 for (MethodMapping methodMapping : new ArrayList<>(methodsByObf.values())) {
-                        String oldMethodKey = getMethodKey(methodMapping.getObfName(), methodMapping.getObfSignature());
+                        String oldMethodKey = getMethodKey(methodMapping.getObfName(), methodMapping.getObfDesc());
                         if (methodMapping.renameObfClass(oldObfClassName, newObfClassName)) {
                                 boolean wasRemoved = methodsByObf.remove(oldMethodKey) != null;
                                 assert (wasRemoved);
                                 boolean wasAdded = methodsByObf
-                                        .put(getMethodKey(methodMapping.getObfName(), methodMapping.getObfSignature()), methodMapping) == null;
+                                        .put(getMethodKey(methodMapping.getObfName(), methodMapping.getObfDesc()), methodMapping) == null;
                                 assert (wasAdded);
                         }
                 }
@@ -490,9 +504,9 @@ public class ClassMapping implements Comparable<ClassMapping> {
                 return false;
         }
 
-        public boolean containsArgument(BehaviorEntry obfBehaviorEntry, String name) {
-                MethodMapping methodMapping = methodsByObf.get(getMethodKey(obfBehaviorEntry.getName(), obfBehaviorEntry.getSignature()));
-                return methodMapping != null && methodMapping.containsArgument(name);
+        public boolean containsArgument(MethodEntry obfMethodEntry, String name) {
+                MethodMapping methodMapping = methodsByObf.get(getMethodKey(obfMethodEntry.getName(), obfMethodEntry.getDesc()));
+                return methodMapping != null && methodMapping.containsLocalVariable(name);
         }
 
         public ClassEntry getObfEntry() {
@@ -503,6 +517,14 @@ public class ClassMapping implements Comparable<ClassMapping> {
                 return deobfFullName != null ? new ClassEntry(deobfFullName) : null;
         }
 
+        public boolean isObfuscated() {
+                return this.deobfName == null || this.deobfName.equals(this.obfFullName);
+        }
+
+        public String getSaveName() {
+                return this.isObfuscated() ? this.obfFullName : this.deobfName;
+        }
+
         public boolean isDirty() {
                 return isDirty;
         }
@@ -511,8 +533,8 @@ public class ClassMapping implements Comparable<ClassMapping> {
                 this.isDirty = false;
         }
 
-        public void markDirty(){
-                isDirty = true;
+        public void markDirty() {
+                this.isDirty = true;
         }
 
         public Mappings.EntryModifier getModifier() {
@@ -525,9 +547,9 @@ public class ClassMapping implements Comparable<ClassMapping> {
                 this.modifier = modifier;
         }
 
-        public void setFieldModifier(String obfName, Type obfType, Mappings.EntryModifier modifier) {
-                FieldMapping fieldMapping = fieldsByObf.computeIfAbsent(getFieldKey(obfName, obfType),
-                        k -> new FieldMapping(obfName, obfType, null, Mappings.EntryModifier.UNCHANGED));
+        public void setFieldModifier(String obfName, TypeDescriptor obfDesc, Mappings.EntryModifier modifier) {
+                FieldMapping fieldMapping = fieldsByObf.computeIfAbsent(getFieldKey(obfName, obfDesc),
+                        k -> new FieldMapping(obfName, obfDesc, null, Mappings.EntryModifier.UNCHANGED));
 
                 if (fieldMapping.getModifier() != modifier) {
                         fieldMapping.setModifier(modifier);
@@ -535,7 +557,7 @@ public class ClassMapping implements Comparable<ClassMapping> {
                 }
         }
 
-        public void setMethodModifier(String obfName, Signature sig, Mappings.EntryModifier modifier) {
+        public void setMethodModifier(String obfName, MethodDescriptor sig, Mappings.EntryModifier modifier) {
                 MethodMapping methodMapping = methodsByObf.computeIfAbsent(getMethodKey(obfName, sig),
                         k -> new MethodMapping(obfName, sig, null, Mappings.EntryModifier.UNCHANGED));
 
@@ -550,4 +572,30 @@ public class ClassMapping implements Comparable<ClassMapping> {
                 this.deobfFullName = deobName;
                 return this;
         }
+
+        public ClassMapping copy() {
+                ClassMapping copied = new ClassMapping(this.obfFullName);
+                copied.obfSimpleName= this.obfSimpleName;
+                copied.modifier = this.modifier;
+                copied.deobfFullName = this.deobfFullName;
+                copied.deobfName = this.deobfName;
+                copied.innerClassesByDeobf = this.innerClassesByDeobf;
+                copied.innerClassesByObfFull = this.innerClassesByObfFull;
+                copied.innerClassesByObfSimple = this.innerClassesByObfSimple;
+                copied.fieldsByObf = this.fieldsByObf;
+                copied.fieldsByDeobf = this.fieldsByDeobf;
+                copied.methodsByObf = this.methodsByObf;
+                copied.methodsByDeobf = this.methodsByDeobf;
+                return copied;
+        }
+
+        @Override
+        public int hashCode() {
+                return this.obfFullName.hashCode();
+        }
+
+        @Override
+        public boolean equals(Object obj) {
+                return obj instanceof ClassMapping && ((ClassMapping) obj).obfFullName.equals(this.obfFullName);
+        }
 }
diff --git a/src/main/java/cuchaz/enigma/mapping/ClassNameReplacer.java b/src/main/java/cuchaz/enigma/mapping/ClassNameReplacer.java
deleted file mode 100644
index 801c410..0000000
--- a/src/main/java/cuchaz/enigma/mapping/ClassNameReplacer.java
+++ /dev/null
@@ -1,16 +0,0 @@
-/*******************************************************************************
- * Copyright (c) 2015 Jeff Martin.
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Lesser General Public
- * License v3.0 which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/lgpl.html
- * <p>
- * Contributors:
- * Jeff Martin - initial API and implementation
- ******************************************************************************/
-
-package cuchaz.enigma.mapping;
-
-public interface ClassNameReplacer {
-        String replace(String className);
-}
diff --git a/src/main/java/cuchaz/enigma/mapping/ConstructorEntry.java b/src/main/java/cuchaz/enigma/mapping/ConstructorEntry.java
deleted file mode 100644
index 20e5113..0000000
--- a/src/main/java/cuchaz/enigma/mapping/ConstructorEntry.java
+++ /dev/null
@@ -1,105 +0,0 @@
-/*******************************************************************************
- * Copyright (c) 2015 Jeff Martin.
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Lesser General Public
- * License v3.0 which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/lgpl.html
- * <p>
- * Contributors:
- * Jeff Martin - initial API and implementation
- ******************************************************************************/
-
-package cuchaz.enigma.mapping;
-
-import cuchaz.enigma.utils.Utils;
-
-public class ConstructorEntry implements BehaviorEntry {
-
-        private ClassEntry classEntry;
-        private Signature signature;
-
-        public ConstructorEntry(ClassEntry classEntry) {
-                this(classEntry, null);
-        }
-
-        public ConstructorEntry(ClassEntry classEntry, Signature signature) {
-                if (classEntry == null) {
-                        throw new IllegalArgumentException("Class cannot be null!");
-                }
-
-                this.classEntry = classEntry;
-                this.signature = signature;
-        }
-
-        public ConstructorEntry(ConstructorEntry other, String newClassName) {
-                this.classEntry = new ClassEntry(newClassName);
-                this.signature = other.signature;
-        }
-
-        @Override
-        public ClassEntry getClassEntry() {
-                return this.classEntry;
-        }
-
-        @Override
-        public String getName() {
-                if (isStatic()) {
-                        return "<clinit>";
-                }
-                return "<init>";
-        }
-
-        public boolean isStatic() {
-                return this.signature == null;
-        }
-
-        @Override
-        public Signature getSignature() {
-                return this.signature;
-        }
-
-        @Override
-        public String getClassName() {
-                return this.classEntry.getName();
-        }
-
-        @Override
-        public ConstructorEntry cloneToNewClass(ClassEntry classEntry) {
-                return new ConstructorEntry(this, classEntry.getName());
-        }
-
-        @Override
-        public int hashCode() {
-                if (isStatic()) {
-                        return Utils.combineHashesOrdered(this.classEntry);
-                } else {
-                        return Utils.combineHashesOrdered(this.classEntry, this.signature);
-                }
-        }
-
-        @Override
-        public boolean equals(Object other) {
-                return other instanceof ConstructorEntry && equals((ConstructorEntry) other);
-        }
-
-        public boolean equals(ConstructorEntry other) {
-                if (isStatic() != other.isStatic()) {
-                        return false;
-                }
-
-                if (isStatic()) {
-                        return this.classEntry.equals(other.classEntry);
-                } else {
-                        return this.classEntry.equals(other.classEntry) && this.signature.equals(other.signature);
-                }
-        }
-
-        @Override
-        public String toString() {
-                if (isStatic()) {
-                        return this.classEntry.getName() + "." + getName();
-                } else {
-                        return this.classEntry.getName() + "." + getName() + this.signature;
-                }
-        }
-}
diff --git a/src/main/java/cuchaz/enigma/mapping/DirectionalTranslator.java b/src/main/java/cuchaz/enigma/mapping/DirectionalTranslator.java
new file mode 100644
index 0000000..b0bb129
--- /dev/null
+++ b/src/main/java/cuchaz/enigma/mapping/DirectionalTranslator.java
@@ -0,0 +1,370 @@
+/*******************************************************************************
+ * Copyright (c) 2015 Jeff Martin.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Lesser General Public
+ * License v3.0 which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/lgpl.html
+ * <p>
+ * Contributors:
+ * Jeff Martin - initial API and implementation
+ ******************************************************************************/
+
+package cuchaz.enigma.mapping;
+
+import com.google.common.collect.Lists;
+import com.google.common.collect.Maps;
+import cuchaz.enigma.analysis.TranslationIndex;
+import cuchaz.enigma.bytecode.AccessFlags;
+import cuchaz.enigma.mapping.entry.*;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Map;
+
+public class DirectionalTranslator implements Translator {
+        private final TranslationDirection direction;
+        private final Map<String, ClassMapping> classes;
+        private final TranslationIndex index;
+
+        public DirectionalTranslator(ReferencedEntryPool entryPool) {
+                this.direction = null;
+                this.classes = Maps.newHashMap();
+                this.index = new TranslationIndex(entryPool);
+        }
+
+        public DirectionalTranslator(TranslationDirection direction, Map<String, ClassMapping> classes, TranslationIndex index) {
+                this.direction = direction;
+                this.classes = classes;
+                this.index = index;
+        }
+
+        public TranslationDirection getDirection() {
+                return direction;
+        }
+
+        public TranslationIndex getTranslationIndex() {
+                return index;
+        }
+
+        @Override
+        public ClassEntry getTranslatedClass(ClassEntry entry) {
+                String className;
+                if (entry.isArray()) {
+                        className = this.getTranslatedTypeDesc(new TypeDescriptor(entry.getName())).toString();
+                } else {
+                        className = entry.isInnerClass() ? translateInnerClassName(entry) : translateClassName(entry);
+                }
+                return new ClassEntry(className);
+        }
+
+        @Override
+        public ClassDefEntry getTranslatedClassDef(ClassDefEntry entry) {
+                String className;
+                if (entry.isArray()) {
+                        className = this.getTranslatedTypeDesc(new TypeDescriptor(entry.getName())).toString();
+                } else {
+                        className = entry.isInnerClass() ? translateInnerClassName(entry) : translateClassName(entry);
+                }
+                Signature translatedSignature = this.getTranslatedSignature(entry.getSignature());
+                return new ClassDefEntry(className, translatedSignature, getClassModifier(entry).transform(entry.getAccess()));
+        }
+
+        private String translateClassName(ClassEntry entry) {
+                // normal classes are easy
+                ClassMapping classMapping = this.classes.get(entry.getName());
+                if (classMapping == null) {
+                        return entry.getName();
+                }
+                return classMapping.getTranslatedName(direction);
+        }
+
+        private String translateInnerClassName(ClassEntry entry) {
+                // translate as much of the class chain as we can
+                List<ClassMapping> mappingsChain = getClassMappingChain(entry);
+                String[] obfClassNames = entry.getName().split("\\$");
+                StringBuilder buf = new StringBuilder();
+                for (int i = 0; i < obfClassNames.length; i++) {
+                        boolean isFirstClass = buf.length() == 0;
+                        String className = null;
+                        ClassMapping classMapping = mappingsChain.get(i);
+                        if (classMapping != null) {
+                                className = this.direction.choose(
+                                                classMapping.getDeobfName(),
+                                                isFirstClass ? classMapping.getObfFullName() : classMapping.getObfSimpleName()
+                                );
+                        }
+                        if (className == null) {
+                                className = obfClassNames[i];
+                        }
+                        if (!isFirstClass) {
+                                buf.append("$");
+                        }
+                        buf.append(className);
+                }
+                return buf.toString();
+        }
+
+        @Override
+        public FieldDefEntry getTranslatedFieldDef(FieldDefEntry entry) {
+                String translatedName = translateFieldName(entry);
+                if (translatedName == null) {
+                        translatedName = entry.getName();
+                }
+                ClassEntry translatedOwner = getTranslatedClass(entry.getOwnerClassEntry());
+                TypeDescriptor translatedDesc = getTranslatedTypeDesc(entry.getDesc());
+                Signature translatedSignature = getTranslatedSignature(entry.getSignature());
+                AccessFlags translatedAccess = getFieldModifier(entry).transform(entry.getAccess());
+                return new FieldDefEntry(translatedOwner, translatedName, translatedDesc, translatedSignature, translatedAccess);
+        }
+
+        @Override
+        public FieldEntry getTranslatedField(FieldEntry entry) {
+                String translatedName = translateFieldName(entry);
+                if (translatedName == null) {
+                        translatedName = entry.getName();
+                }
+                ClassEntry translatedOwner = getTranslatedClass(entry.getOwnerClassEntry());
+                TypeDescriptor translatedDesc = getTranslatedTypeDesc(entry.getDesc());
+                return new FieldEntry(translatedOwner, translatedName, translatedDesc);
+        }
+
+        private String translateFieldName(FieldEntry entry) {
+                // resolve the class entry
+                ClassEntry resolvedClassEntry = this.index.resolveEntryOwner(entry, true);
+                if (resolvedClassEntry != null) {
+                        // look for the class
+                        ClassMapping classMapping = findClassMapping(resolvedClassEntry);
+                        if (classMapping != null) {
+                                // look for the field
+                                FieldMapping mapping = this.direction.choose(
+                                                classMapping.getFieldByObf(entry.getName(), entry.getDesc()),
+                                                classMapping.getFieldByDeobf(entry.getName(), getTranslatedTypeDesc(entry.getDesc()))
+                                );
+                                if (mapping != null) {
+                                        return this.direction.choose(mapping.getDeobfName(), mapping.getObfName());
+                                }
+                        }
+                }
+                return null;
+        }
+
+        @Override
+        public MethodDefEntry getTranslatedMethodDef(MethodDefEntry entry) {
+                String translatedName = translateMethodName(entry);
+                if (translatedName == null) {
+                        translatedName = entry.getName();
+                }
+                ClassEntry translatedOwner = getTranslatedClass(entry.getOwnerClassEntry());
+                MethodDescriptor translatedDesc = getTranslatedMethodDesc(entry.getDesc());
+                Signature translatedSignature = getTranslatedSignature(entry.getSignature());
+                AccessFlags access = getMethodModifier(entry).transform(entry.getAccess());
+                return new MethodDefEntry(translatedOwner, translatedName, translatedDesc, translatedSignature, access);
+        }
+
+        @Override
+        public MethodEntry getTranslatedMethod(MethodEntry entry) {
+                String translatedName = translateMethodName(entry);
+                if (translatedName == null) {
+                        translatedName = entry.getName();
+                }
+                ClassEntry translatedOwner = getTranslatedClass(entry.getOwnerClassEntry());
+                MethodDescriptor translatedDesc = getTranslatedMethodDesc(entry.getDesc());
+                return new MethodEntry(translatedOwner, translatedName, translatedDesc);
+        }
+
+        private String translateMethodName(MethodEntry entry) {
+                // resolve the class entry
+                ClassEntry resolvedOwner = this.index.resolveEntryOwner(entry, true);
+                if (resolvedOwner != null) {
+                        // look for class
+                        ClassMapping classMapping = findClassMapping(resolvedOwner);
+                        if (classMapping != null) {
+                                // look for the method
+                                MethodMapping mapping = this.direction.choose(
+                                                classMapping.getMethodByObf(entry.getName(), entry.getDesc()),
+                                                classMapping.getMethodByDeobf(entry.getName(), getTranslatedMethodDesc(entry.getDesc()))
+                                );
+                                if (mapping != null) {
+                                        return this.direction.choose(mapping.getDeobfName(), mapping.getObfName());
+                                }
+                        }
+                }
+                return null;
+        }
+
+        @Override
+        public LocalVariableEntry getTranslatedVariable(LocalVariableEntry entry) {
+                String translatedArgumentName = translateLocalVariableName(entry);
+                if (translatedArgumentName == null) {
+                        translatedArgumentName = inheritLocalVariableName(entry);
+                }
+                if (translatedArgumentName == null) {
+                        translatedArgumentName = entry.getName();
+                }
+                // TODO: Translating arguments calls method translation.. Can we refactor the code in such a way that we don't need this?
+                MethodEntry translatedOwner = getTranslatedMethod(entry.getOwnerEntry());
+                return new LocalVariableEntry(translatedOwner, entry.getIndex(), translatedArgumentName);
+        }
+
+        @Override
+        public LocalVariableDefEntry getTranslatedVariableDef(LocalVariableDefEntry entry) {
+                String translatedArgumentName = translateLocalVariableName(entry);
+                if (translatedArgumentName == null) {
+                        translatedArgumentName = inheritLocalVariableName(entry);
+                }
+                // TODO: Translating arguments calls method translation.. Can we refactor the code in such a way that we don't need this?
+                MethodDefEntry translatedOwner = getTranslatedMethodDef(entry.getOwnerEntry());
+                TypeDescriptor translatedTypeDesc = getTranslatedTypeDesc(entry.getDesc());
+                return new LocalVariableDefEntry(translatedOwner, entry.getIndex(), translatedArgumentName != null ? translatedArgumentName : entry.getName(), translatedTypeDesc);
+        }
+
+        @Override
+        public boolean hasClassMapping(ClassEntry entry) {
+                return classes.containsKey(entry.getName());
+        }
+
+        @Override
+        public boolean hasFieldMapping(FieldEntry entry) {
+                return translateFieldName(entry) != null;
+        }
+
+        @Override
+        public boolean hasMethodMapping(MethodEntry entry) {
+                return translateMethodName(entry) != null;
+        }
+
+        @Override
+        public boolean hasLocalVariableMapping(LocalVariableEntry entry) {
+                return translateLocalVariableName(entry) != null || inheritLocalVariableName(entry) != null;
+        }
+
+        // TODO: support not identical behavior (specific to constructor)
+        private String translateLocalVariableName(LocalVariableEntry entry) {
+                // look for identical behavior in superclasses
+                ClassEntry ownerEntry = entry.getOwnerClassEntry();
+                if (ownerEntry != null) {
+                        // look for the class
+                        ClassMapping classMapping = findClassMapping(ownerEntry);
+                        if (classMapping != null) {
+                                // look for the method
+                                MethodMapping methodMapping = this.direction.choose(
+                                                classMapping.getMethodByObf(entry.getMethodName(), entry.getMethodDesc()),
+                                                classMapping.getMethodByDeobf(entry.getMethodName(), getTranslatedMethodDesc(entry.getMethodDesc()))
+                                );
+                                if (methodMapping != null) {
+                                        int index = entry.getIndex();
+                                        return this.direction.choose(
+                                                        methodMapping.getDeobfLocalVariableName(index),
+                                                        methodMapping.getObfLocalVariableName(index)
+                                        );
+                                }
+                        }
+                }
+                return null;
+        }
+
+        private String inheritLocalVariableName(LocalVariableEntry entry) {
+                List<ClassEntry> ancestry = this.index.getAncestry(entry.getOwnerClassEntry());
+                // Check in mother class for the arg
+                for (ClassEntry ancestorEntry : ancestry) {
+                        LocalVariableEntry motherArg = entry.updateOwnership(ancestorEntry);
+                        if (this.index.entryExists(motherArg)) {
+                                String result = translateLocalVariableName(motherArg);
+                                if (result != null) {
+                                        return result;
+                                }
+                        }
+                }
+                return null;
+        }
+
+        @Override
+        public TypeDescriptor getTranslatedTypeDesc(TypeDescriptor desc) {
+                return desc.remap(this::remapClass);
+        }
+
+        @Override
+        public MethodDescriptor getTranslatedMethodDesc(MethodDescriptor descriptor) {
+                List<TypeDescriptor> arguments = descriptor.getArgumentDescs();
+                List<TypeDescriptor> translatedArguments = new ArrayList<>(arguments.size());
+                for (TypeDescriptor argument : arguments) {
+                        translatedArguments.add(getTranslatedTypeDesc(argument));
+                }
+                return new MethodDescriptor(translatedArguments, getTranslatedTypeDesc(descriptor.getReturnDesc()));
+        }
+
+        @Override
+        public Signature getTranslatedSignature(Signature signature) {
+                if (signature == null) {
+                        return null;
+                }
+                return signature.remap(this::remapClass);
+        }
+
+        private ClassMapping findClassMapping(ClassEntry entry) {
+                List<ClassMapping> mappingChain = getClassMappingChain(entry);
+                return mappingChain.get(mappingChain.size() - 1);
+        }
+
+        private List<ClassMapping> getClassMappingChain(ClassEntry entry) {
+
+                // get a list of all the classes in the hierarchy
+                String[] parts = entry.getName().split("\\$");
+                List<ClassMapping> mappingsChain = Lists.newArrayList();
+
+                // get mappings for the outer class
+                ClassMapping outerClassMapping = this.classes.get(parts[0]);
+                mappingsChain.add(outerClassMapping);
+
+                for (int i = 1; i < parts.length; i++) {
+
+                        // get mappings for the inner class
+                        ClassMapping innerClassMapping = null;
+                        if (outerClassMapping != null) {
+                                innerClassMapping = this.direction.choose(
+                                                outerClassMapping.getInnerClassByObfSimple(parts[i]),
+                                                outerClassMapping.getInnerClassByDeobfThenObfSimple(parts[i])
+                                );
+                        }
+                        mappingsChain.add(innerClassMapping);
+                        outerClassMapping = innerClassMapping;
+                }
+
+                assert (mappingsChain.size() == parts.length);
+                return mappingsChain;
+        }
+
+        private Mappings.EntryModifier getClassModifier(ClassEntry entry) {
+                ClassMapping classMapping = findClassMapping(entry);
+                if (classMapping != null) {
+                        return classMapping.getModifier();
+                }
+                return Mappings.EntryModifier.UNCHANGED;
+        }
+
+        private Mappings.EntryModifier getFieldModifier(FieldEntry entry) {
+                ClassMapping classMapping = findClassMapping(entry.getOwnerClassEntry());
+                if (classMapping != null) {
+                        FieldMapping fieldMapping = classMapping.getFieldByObf(entry);
+                        if (fieldMapping != null) {
+                                return fieldMapping.getModifier();
+                        }
+                }
+                return Mappings.EntryModifier.UNCHANGED;
+        }
+
+        private Mappings.EntryModifier getMethodModifier(MethodEntry entry) {
+                ClassMapping classMapping = findClassMapping(entry.getOwnerClassEntry());
+                if (classMapping != null) {
+                        MethodMapping methodMapping = classMapping.getMethodByObf(entry);
+                        if (methodMapping != null) {
+                                return methodMapping.getModifier();
+                        }
+                }
+                return Mappings.EntryModifier.UNCHANGED;
+        }
+
+        private String remapClass(String name) {
+                return getTranslatedClass(new ClassEntry(name)).getName();
+        }
+}
diff --git a/src/main/java/cuchaz/enigma/mapping/EntryFactory.java b/src/main/java/cuchaz/enigma/mapping/EntryFactory.java
deleted file mode 100644
index 993bb64..0000000
--- a/src/main/java/cuchaz/enigma/mapping/EntryFactory.java
+++ /dev/null
@@ -1,132 +0,0 @@
-/*******************************************************************************
- * Copyright (c) 2015 Jeff Martin.
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Lesser General Public
- * License v3.0 which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/lgpl.html
- * <p>
- * Contributors:
- * Jeff Martin - initial API and implementation
- ******************************************************************************/
-
-package cuchaz.enigma.mapping;
-
-import cuchaz.enigma.analysis.JarIndex;
-import javassist.*;
-import javassist.bytecode.Descriptor;
-import javassist.expr.ConstructorCall;
-import javassist.expr.FieldAccess;
-import javassist.expr.MethodCall;
-import javassist.expr.NewExpr;
-
-public class EntryFactory {
-
-        public static ClassEntry getClassEntry(CtClass c) {
-                return new ClassEntry(Descriptor.toJvmName(c.getName()));
-        }
-
-        public static ClassEntry getObfClassEntry(JarIndex jarIndex, ClassMapping classMapping) {
-                ClassEntry obfClassEntry = new ClassEntry(classMapping.getObfFullName());
-                return obfClassEntry.buildClassEntry(jarIndex.getObfClassChain(obfClassEntry));
-        }
-
-        private static ClassEntry getObfClassEntry(ClassMapping classMapping) {
-                return new ClassEntry(classMapping.getObfFullName());
-        }
-
-        public static ClassEntry getDeobfClassEntry(ClassMapping classMapping) {
-                return new ClassEntry(classMapping.getDeobfName());
-        }
-
-        public static ClassEntry getSuperclassEntry(CtClass c) {
-                return new ClassEntry(Descriptor.toJvmName(c.getClassFile().getSuperclass()));
-        }
-
-        public static FieldEntry getFieldEntry(CtField field) {
-                return new FieldEntry(getClassEntry(field.getDeclaringClass()), field.getName(), new Type(field.getFieldInfo().getDescriptor()));
-        }
-
-        public static FieldEntry getFieldEntry(FieldAccess call) {
-                return new FieldEntry(new ClassEntry(Descriptor.toJvmName(call.getClassName())), call.getFieldName(), new Type(call.getSignature()));
-        }
-
-        public static FieldEntry getFieldEntry(String className, String name, String type) {
-                return new FieldEntry(new ClassEntry(className), name, new Type(type));
-        }
-
-        public static FieldEntry getObfFieldEntry(ClassMapping classMapping, FieldMapping fieldMapping) {
-                return new FieldEntry(getObfClassEntry(classMapping), fieldMapping.getObfName(), fieldMapping.getObfType());
-        }
-
-        public static MethodEntry getMethodEntry(CtMethod method) {
-                return new MethodEntry(getClassEntry(method.getDeclaringClass()), method.getName(), new Signature(method.getMethodInfo().getDescriptor()));
-        }
-
-        public static MethodEntry getMethodEntry(MethodCall call) {
-                return new MethodEntry(new ClassEntry(Descriptor.toJvmName(call.getClassName())), call.getMethodName(), new Signature(call.getSignature()));
-        }
-
-        public static ConstructorEntry getConstructorEntry(CtConstructor constructor) {
-                if (constructor.isClassInitializer()) {
-                        return new ConstructorEntry(getClassEntry(constructor.getDeclaringClass()));
-                } else {
-                        return new ConstructorEntry(getClassEntry(constructor.getDeclaringClass()), new Signature(constructor.getMethodInfo().getDescriptor()));
-                }
-        }
-
-        public static ConstructorEntry getConstructorEntry(ConstructorCall call) {
-                return new ConstructorEntry(new ClassEntry(Descriptor.toJvmName(call.getClassName())), new Signature(call.getSignature()));
-        }
-
-        public static ConstructorEntry getConstructorEntry(NewExpr call) {
-                return new ConstructorEntry(new ClassEntry(Descriptor.toJvmName(call.getClassName())), new Signature(call.getSignature()));
-        }
-
-        public static BehaviorEntry getBehaviorEntry(CtBehavior behavior) {
-                if (behavior instanceof CtMethod) {
-                        return getMethodEntry((CtMethod) behavior);
-                } else if (behavior instanceof CtConstructor) {
-                        return getConstructorEntry((CtConstructor) behavior);
-                }
-                throw new Error("behavior is neither Method nor Constructor!");
-        }
-
-        public static BehaviorEntry getBehaviorEntry(String className, String behaviorName, String behaviorSignature) {
-                return getBehaviorEntry(new ClassEntry(className), behaviorName, new Signature(behaviorSignature));
-        }
-
-        public static BehaviorEntry getBehaviorEntry(String className, String behaviorName) {
-                return getBehaviorEntry(new ClassEntry(className), behaviorName);
-        }
-
-        public static BehaviorEntry getBehaviorEntry(String className) {
-                return new ConstructorEntry(new ClassEntry(className));
-        }
-
-        public static BehaviorEntry getBehaviorEntry(ClassEntry classEntry, String behaviorName, Signature behaviorSignature) {
-                switch (behaviorName) {
-                        case "<init>":
-                                return new ConstructorEntry(classEntry, behaviorSignature);
-                        case "<clinit>":
-                                return new ConstructorEntry(classEntry);
-                        default:
-                                return new MethodEntry(classEntry, behaviorName, behaviorSignature);
-                }
-        }
-
-        public static BehaviorEntry getBehaviorEntry(ClassEntry classEntry, String behaviorName) {
-                if (behaviorName.equals("<clinit>")) {
-                        return new ConstructorEntry(classEntry);
-                } else {
-                        throw new IllegalArgumentException("Only class initializers don't have signatures");
-                }
-        }
-
-        public static BehaviorEntry getObfBehaviorEntry(ClassEntry classEntry, MethodMapping methodMapping) {
-                return getBehaviorEntry(classEntry, methodMapping.getObfName(), methodMapping.getObfSignature());
-        }
-
-        public static BehaviorEntry getObfBehaviorEntry(ClassMapping classMapping, MethodMapping methodMapping) {
-                return getObfBehaviorEntry(getObfClassEntry(classMapping), methodMapping);
-        }
-}
diff --git a/src/main/java/cuchaz/enigma/mapping/FieldEntry.java b/src/main/java/cuchaz/enigma/mapping/FieldEntry.java
deleted file mode 100644
index 0f1f506..0000000
--- a/src/main/java/cuchaz/enigma/mapping/FieldEntry.java
+++ /dev/null
@@ -1,87 +0,0 @@
-/*******************************************************************************
- * Copyright (c) 2015 Jeff Martin.
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Lesser General Public
- * License v3.0 which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/lgpl.html
- * <p>
- * Contributors:
- * Jeff Martin - initial API and implementation
- ******************************************************************************/
-
-package cuchaz.enigma.mapping;
-
-import cuchaz.enigma.utils.Utils;
-
-public class FieldEntry implements Entry {
-
-        private ClassEntry classEntry;
-        private String name;
-        private Type type;
-
-        // NOTE: this argument order is important for the MethodReader/MethodWriter
-        public FieldEntry(ClassEntry classEntry, String name, Type type) {
-                if (classEntry == null) {
-                        throw new IllegalArgumentException("Class cannot be null!");
-                }
-                if (name == null) {
-                        throw new IllegalArgumentException("Field name cannot be null!");
-                }
-                if (type == null) {
-                        throw new IllegalArgumentException("Field type cannot be null!");
-                }
-
-                this.classEntry = classEntry;
-                this.name = name;
-                this.type = type;
-        }
-
-        public FieldEntry(FieldEntry other, ClassEntry newClassEntry) {
-                this.classEntry = newClassEntry;
-                this.name = other.name;
-                this.type = other.type;
-        }
-
-        @Override
-        public ClassEntry getClassEntry() {
-                return this.classEntry;
-        }
-
-        @Override
-        public String getName() {
-                return this.name;
-        }
-
-        @Override
-        public String getClassName() {
-                return this.classEntry.getName();
-        }
-
-        public Type getType() {
-                return this.type;
-        }
-
-        @Override
-        public FieldEntry cloneToNewClass(ClassEntry classEntry) {
-                return new FieldEntry(this, classEntry);
-        }
-
-        @Override
-        public int hashCode() {
-                return Utils.combineHashesOrdered(this.classEntry, this.name, this.type);
-        }
-
-        @Override
-        public boolean equals(Object other) {
-                return other instanceof FieldEntry && equals((FieldEntry) other);
-        }
-
-        public boolean equals(FieldEntry other) {
-                return this.classEntry.equals(other.classEntry) && this.name.equals(other.name) && this.type.equals(other.type);
-        }
-
-        @Override
-        public String toString() {
-                return this.classEntry.getName() + "." + this.name + ":" + this.type;
-        }
-}
diff --git a/src/main/java/cuchaz/enigma/mapping/FieldMapping.java b/src/main/java/cuchaz/enigma/mapping/FieldMapping.java
index cd761b4..8fbe095 100644
--- a/src/main/java/cuchaz/enigma/mapping/FieldMapping.java
+++ b/src/main/java/cuchaz/enigma/mapping/FieldMapping.java
@@ -11,32 +11,27 @@
 
 package cuchaz.enigma.mapping;
 
+import cuchaz.enigma.mapping.entry.ClassEntry;
+import cuchaz.enigma.mapping.entry.FieldEntry;
 import cuchaz.enigma.throwables.IllegalNameException;
 
 public class FieldMapping implements Comparable<FieldMapping>, MemberMapping<FieldEntry> {
 
         private String obfName;
         private String deobfName;
-        private Type obfType;
+        private TypeDescriptor obfDesc;
         private Mappings.EntryModifier modifier;
 
-        public FieldMapping(String obfName, Type obfType, String deobfName, Mappings.EntryModifier modifier) {
+        public FieldMapping(String obfName, TypeDescriptor obfDesc, String deobfName, Mappings.EntryModifier modifier) {
                 this.obfName = obfName;
                 this.deobfName = NameValidator.validateFieldName(deobfName);
-                this.obfType = obfType;
+                this.obfDesc = obfDesc;
                 this.modifier = modifier;
         }
 
-        public FieldMapping(FieldMapping other, ClassNameReplacer obfClassNameReplacer) {
-                this.obfName = other.obfName;
-                this.deobfName = other.deobfName;
-                this.modifier = other.modifier;
-                this.obfType = new Type(other.obfType, obfClassNameReplacer);
-        }
-
         @Override
         public FieldEntry getObfEntry(ClassEntry classEntry) {
-                return new FieldEntry(classEntry, this.obfName, this.obfType);
+                return new FieldEntry(classEntry, this.obfName, this.obfDesc);
         }
 
         @Override
@@ -65,12 +60,12 @@ public class FieldMapping implements Comparable<FieldMapping>, MemberMapping<Fie
                 this.deobfName = NameValidator.validateFieldName(val);
         }
 
-        public Type getObfType() {
-                return this.obfType;
+        public TypeDescriptor getObfDesc() {
+                return this.obfDesc;
         }
 
-        public void setObfType(Type val) {
-                this.obfType = val;
+        public void setObfDesc(TypeDescriptor val) {
+                this.obfDesc = val;
         }
 
         public Mappings.EntryModifier getModifier() {
@@ -83,21 +78,20 @@ public class FieldMapping implements Comparable<FieldMapping>, MemberMapping<Fie
 
         @Override
         public int compareTo(FieldMapping other) {
-                return (this.obfName + this.obfType).compareTo(other.obfName + other.obfType);
+                return (this.obfName + this.obfDesc).compareTo(other.obfName + other.obfDesc);
         }
 
         public boolean renameObfClass(final String oldObfClassName, final String newObfClassName) {
-                // rename obf classes in the type
-                Type newType = new Type(this.obfType, className ->
-                {
+                // rename obf classes in the desc
+                TypeDescriptor newDesc = this.obfDesc.remap(className -> {
                         if (className.equals(oldObfClassName)) {
                                 return newObfClassName;
                         }
-                        return null;
+                        return className;
                 });
 
-                if (!newType.equals(this.obfType)) {
-                        this.obfType = newType;
+                if (!newDesc.equals(this.obfDesc)) {
+                        this.obfDesc = newDesc;
                         return true;
                 }
                 return false;
diff --git a/src/main/java/cuchaz/enigma/mapping/LocalVariableEntry.java b/src/main/java/cuchaz/enigma/mapping/LocalVariableEntry.java
deleted file mode 100644
index 2bb5e3f..0000000
--- a/src/main/java/cuchaz/enigma/mapping/LocalVariableEntry.java
+++ /dev/null
@@ -1,102 +0,0 @@
-package cuchaz.enigma.mapping;
-
-import cuchaz.enigma.utils.Utils;
-
-/**
- * Desc...
- * Created by Thog
- * 19/10/2016
- */
-public class LocalVariableEntry implements Entry {
-
-        protected final BehaviorEntry behaviorEntry;
-        protected final String name;
-        protected final Type type;
-        protected final int index;
-
-        public LocalVariableEntry(BehaviorEntry behaviorEntry, int index, String name, Type type) {
-                if (behaviorEntry == null) {
-                        throw new IllegalArgumentException("Behavior cannot be null!");
-                }
-                if (index < 0) {
-                        throw new IllegalArgumentException("Index must be non-negative!");
-                }
-                if (name == null) {
-                        throw new IllegalArgumentException("Variable name cannot be null!");
-                }
-                if (type == null) {
-                        throw new IllegalArgumentException("Variable type cannot be null!");
-                }
-
-                this.behaviorEntry = behaviorEntry;
-                this.name = name;
-                this.type = type;
-                this.index = index;
-        }
-
-        public LocalVariableEntry(LocalVariableEntry other, ClassEntry newClassEntry) {
-                this.behaviorEntry = (BehaviorEntry) other.behaviorEntry.cloneToNewClass(newClassEntry);
-                this.name = other.name;
-                this.type = other.type;
-                this.index = other.index;
-        }
-
-        public BehaviorEntry getBehaviorEntry() {
-                return this.behaviorEntry;
-        }
-
-        public Type getType() {
-                return type;
-        }
-
-        public int getIndex() {
-                return index;
-        }
-
-        @Override
-        public String getName() {
-                return this.name;
-        }
-
-        @Override
-        public ClassEntry getClassEntry() {
-                return this.behaviorEntry.getClassEntry();
-        }
-
-        @Override
-        public String getClassName() {
-                return this.behaviorEntry.getClassName();
-        }
-
-        @Override
-        public LocalVariableEntry cloneToNewClass(ClassEntry classEntry) {
-                return new LocalVariableEntry(this, classEntry);
-        }
-
-        public String getMethodName() {
-                return this.behaviorEntry.getName();
-        }
-
-        public Signature getMethodSignature() {
-                return this.behaviorEntry.getSignature();
-        }
-
-        @Override
-        public int hashCode() {
-                return Utils.combineHashesOrdered(this.behaviorEntry, this.type.hashCode(), this.name.hashCode(), Integer.hashCode(this.index));
-        }
-
-        @Override
-        public boolean equals(Object other) {
-                return other instanceof LocalVariableEntry && equals((LocalVariableEntry) other);
-        }
-
-        public boolean equals(LocalVariableEntry other) {
-                return this.behaviorEntry.equals(other.behaviorEntry) && this.type.equals(other.type) && this.name.equals(other.name) && this.index == other.index;
-        }
-
-        @Override
-        public String toString() {
-                return this.behaviorEntry + "(" + this.index + ":" + this.name + ":" + this.type + ")";
-        }
-}
diff --git a/src/main/java/cuchaz/enigma/mapping/ArgumentMapping.java b/src/main/java/cuchaz/enigma/mapping/LocalVariableMapping.java
index 91ecd10..62dbcf3 100644
--- a/src/main/java/cuchaz/enigma/mapping/ArgumentMapping.java
+++ b/src/main/java/cuchaz/enigma/mapping/LocalVariableMapping.java
@@ -11,18 +11,21 @@
 
 package cuchaz.enigma.mapping;
 
-public class ArgumentMapping implements Comparable<ArgumentMapping> {
+import cuchaz.enigma.mapping.entry.LocalVariableEntry;
+import cuchaz.enigma.mapping.entry.MethodEntry;
+
+public class LocalVariableMapping implements Comparable<LocalVariableMapping> {
 
         private int index;
         private String name;
 
         // NOTE: this argument order is important for the MethodReader/MethodWriter
-        public ArgumentMapping(int index, String name) {
+        public LocalVariableMapping(int index, String name) {
                 this.index = index;
                 this.name = NameValidator.validateArgumentName(name);
         }
 
-        public ArgumentMapping(ArgumentMapping other) {
+        public LocalVariableMapping(LocalVariableMapping other) {
                 this.index = other.index;
                 this.name = other.name;
         }
@@ -39,12 +42,12 @@ public class ArgumentMapping implements Comparable<ArgumentMapping> {
                 this.name = NameValidator.validateArgumentName(val);
         }
 
-        public ArgumentEntry getObfEntry(BehaviorEntry behaviorEntry) {
-                return new ArgumentEntry(behaviorEntry, index, name);
+        public LocalVariableEntry getObfEntry(MethodEntry methodEntry) {
+                return new LocalVariableEntry(methodEntry, index, name);
         }
 
         @Override
-        public int compareTo(ArgumentMapping other) {
+        public int compareTo(LocalVariableMapping other) {
                 return Integer.compare(this.index, other.index);
         }
 }
diff --git a/src/main/java/cuchaz/enigma/mapping/Mappings.java b/src/main/java/cuchaz/enigma/mapping/Mappings.java
index cf78ca3..3ef1be5 100644
--- a/src/main/java/cuchaz/enigma/mapping/Mappings.java
+++ b/src/main/java/cuchaz/enigma/mapping/Mappings.java
@@ -15,11 +15,15 @@ import com.google.common.collect.Lists;
 import com.google.common.collect.Maps;
 import com.google.common.collect.Sets;
 import cuchaz.enigma.analysis.TranslationIndex;
+import cuchaz.enigma.bytecode.AccessFlags;
+import cuchaz.enigma.mapping.entry.ClassEntry;
+import cuchaz.enigma.mapping.entry.MethodEntry;
 import cuchaz.enigma.throwables.MappingConflict;
 
 import java.io.File;
 import java.io.IOException;
 import java.util.*;
+import java.util.stream.Collectors;
 
 public class Mappings {
 
@@ -96,11 +100,11 @@ public class Mappings {
 
         public Translator getTranslator(TranslationDirection direction, TranslationIndex index) {
                 switch (direction) {
-                        case Deobfuscating:
+                        case DEOBFUSCATING:
 
-                                return new Translator(direction, this.classesByObf, index);
+                                return new DirectionalTranslator(direction, this.classesByObf, index);
 
-                        case Obfuscating:
+                        case OBFUSCATING:
 
                                 // fill in the missing deobf class entries with obf entries
                                 Map<String, ClassMapping> classes = Maps.newHashMap();
@@ -114,9 +118,9 @@ public class Mappings {
 
                                 // translate the translation index
                                 // NOTE: this isn't actually recursive
-                                TranslationIndex deobfIndex = new TranslationIndex(index, getTranslator(TranslationDirection.Deobfuscating, index));
+                                TranslationIndex deobfIndex = new TranslationIndex(index, getTranslator(TranslationDirection.DEOBFUSCATING, index));
 
-                                return new Translator(direction, classes, deobfIndex);
+                                return new DirectionalTranslator(direction, classes, deobfIndex);
 
                         default:
                                 throw new Error("Invalid translation direction!");
@@ -151,9 +155,9 @@ public class Mappings {
 
                         // add classes from method signatures
                         for (MethodMapping methodMapping : classMapping.methods()) {
-                                for (Type type : methodMapping.getObfSignature().types()) {
-                                        if (type.hasClass()) {
-                                                classNames.add(type.getClassEntry().getClassName());
+                                for (TypeDescriptor desc : methodMapping.getObfDesc().types()) {
+                                        if (desc.containsType()) {
+                                                classNames.add(desc.getTypeEntry().getClassName());
                                         }
                                 }
                         }
@@ -165,9 +169,9 @@ public class Mappings {
                 return this.classesByDeobf.containsKey(deobfName);
         }
 
-        public boolean containsDeobfField(ClassEntry obfClassEntry, String deobfName, Type obfType) {
+        public boolean containsDeobfField(ClassEntry obfClassEntry, String deobfName, TypeDescriptor obfDesc) {
                 ClassMapping classMapping = this.classesByObf.get(obfClassEntry.getName());
-                return classMapping != null && classMapping.containsDeobfField(deobfName, obfType);
+                return classMapping != null && classMapping.containsDeobfField(deobfName, obfDesc);
         }
 
         public boolean containsDeobfField(ClassEntry obfClassEntry, String deobfName) {
@@ -180,14 +184,14 @@ public class Mappings {
                 return false;
         }
 
-        public boolean containsDeobfMethod(ClassEntry obfClassEntry, String deobfName, Signature obfSignature) {
+        public boolean containsDeobfMethod(ClassEntry obfClassEntry, String deobfName, MethodDescriptor obfDescriptor) {
                 ClassMapping classMapping = this.classesByObf.get(obfClassEntry.getName());
-                return classMapping != null && classMapping.containsDeobfMethod(deobfName, obfSignature);
+                return classMapping != null && classMapping.containsDeobfMethod(deobfName, obfDescriptor);
         }
 
-        public boolean containsArgument(BehaviorEntry obfBehaviorEntry, String name) {
-                ClassMapping classMapping = this.classesByObf.get(obfBehaviorEntry.getClassName());
-                return classMapping != null && classMapping.containsArgument(obfBehaviorEntry, name);
+        public boolean containsArgument(MethodEntry obfMethodEntry, String name) {
+                ClassMapping classMapping = this.classesByObf.get(obfMethodEntry.getClassName());
+                return classMapping != null && classMapping.containsArgument(obfMethodEntry, name);
         }
 
         public List<ClassMapping> getClassMappingChain(ClassEntry obfClass) {
@@ -210,8 +214,14 @@ public class Mappings {
 
         public void savePreviousState() {
                 this.previousState = new Mappings(this.originMapping);
-                this.previousState.classesByDeobf = Maps.newHashMap(this.classesByDeobf);
-                this.previousState.classesByObf = Maps.newHashMap(this.classesByObf);
+                this.previousState.classesByDeobf = new HashMap<>();
+                for (Map.Entry<String, ClassMapping> entry : this.classesByDeobf.entrySet()) {
+                        this.previousState.classesByDeobf.put(entry.getKey(), entry.getValue().copy());
+                }
+                this.previousState.classesByObf = new HashMap<>();
+                for (Map.Entry<String, ClassMapping> entry : this.classesByObf.entrySet()) {
+                        this.previousState.classesByObf.put(entry.getKey(), entry.getValue().copy());
+                }
                 classesByDeobf.values().forEach(ClassMapping::resetDirty);
                 classesByObf.values().forEach(ClassMapping::resetDirty);
         }
@@ -239,5 +249,19 @@ public class Mappings {
                 public String getFormattedName() {
                         return " ACC:" + super.toString();
                 }
+
+                public AccessFlags transform(AccessFlags access) {
+                        switch (this) {
+                                case PUBLIC:
+                                        return access.setPublic();
+                                case PROTECTED:
+                                        return access.setProtected();
+                                case PRIVATE:
+                                        return access.setPrivate();
+                                case UNCHANGED:
+                                default:
+                                        return access;
+                        }
+                }
         }
 }
diff --git a/src/main/java/cuchaz/enigma/mapping/MappingsChecker.java b/src/main/java/cuchaz/enigma/mapping/MappingsChecker.java
index 172641b..a42f255 100644
--- a/src/main/java/cuchaz/enigma/mapping/MappingsChecker.java
+++ b/src/main/java/cuchaz/enigma/mapping/MappingsChecker.java
@@ -14,6 +14,10 @@ package cuchaz.enigma.mapping;
 import com.google.common.collect.Lists;
 import com.google.common.collect.Maps;
 import cuchaz.enigma.analysis.JarIndex;
+import cuchaz.enigma.mapping.entry.ClassEntry;
+import cuchaz.enigma.mapping.entry.EntryFactory;
+import cuchaz.enigma.mapping.entry.FieldEntry;
+import cuchaz.enigma.mapping.entry.MethodEntry;
 
 import java.util.Map;
 
@@ -23,7 +27,7 @@ public class MappingsChecker {
         private Map<ClassEntry, ClassMapping> droppedClassMappings;
         private Map<ClassEntry, ClassMapping> droppedInnerClassMappings;
         private Map<FieldEntry, FieldMapping> droppedFieldMappings;
-        private Map<BehaviorEntry, MethodMapping> droppedMethodMappings;
+        private Map<MethodEntry, MethodMapping> droppedMethodMappings;
 
         public MappingsChecker(JarIndex index) {
                 this.index = index;
@@ -45,7 +49,7 @@ public class MappingsChecker {
                 return this.droppedFieldMappings;
         }
 
-        public Map<BehaviorEntry, MethodMapping> getDroppedMethodMappings() {
+        public Map<MethodEntry, MethodMapping> getDroppedMethodMappings() {
                 return this.droppedMethodMappings;
         }
 
@@ -77,10 +81,10 @@ public class MappingsChecker {
 
                 // check methods
                 for (MethodMapping methodMapping : Lists.newArrayList(classMapping.methods())) {
-                        BehaviorEntry obfBehaviorEntry = EntryFactory.getObfBehaviorEntry(classEntry, methodMapping);
-                        if (!this.index.containsObfBehavior(obfBehaviorEntry)) {
+                        MethodEntry obfMethodEntry = EntryFactory.getObfMethodEntry(classEntry, methodMapping);
+                        if (!this.index.containsObfMethod(obfMethodEntry)) {
                                 classMapping.removeMethodMapping(methodMapping);
-                                this.droppedMethodMappings.put(obfBehaviorEntry, methodMapping);
+                                this.droppedMethodMappings.put(obfMethodEntry, methodMapping);
                         }
                 }
 
diff --git a/src/main/java/cuchaz/enigma/mapping/MappingsEnigmaReader.java b/src/main/java/cuchaz/enigma/mapping/MappingsEnigmaReader.java
index a0d4313..ddbee76 100644
--- a/src/main/java/cuchaz/enigma/mapping/MappingsEnigmaReader.java
+++ b/src/main/java/cuchaz/enigma/mapping/MappingsEnigmaReader.java
@@ -5,8 +5,14 @@ import com.google.common.collect.Queues;
 import cuchaz.enigma.throwables.MappingConflict;
 import cuchaz.enigma.throwables.MappingParseException;
 
-import java.io.*;
+import java.io.BufferedReader;
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
 import java.util.Deque;
+import java.util.function.Supplier;
 
 public class MappingsEnigmaReader {
 
@@ -39,92 +45,95 @@ public class MappingsEnigmaReader {
         }
 
         public Mappings readFile(Mappings mappings, File file) throws IOException, MappingParseException {
+                return readFileStream(mappings, new FileInputStream(file), file::getAbsolutePath);
+        }
 
-                BufferedReader in = new BufferedReader(new InputStreamReader(new FileInputStream(file), Charsets.UTF_8));
-                Deque<Object> mappingStack = Queues.newArrayDeque();
+        public Mappings readFileStream(Mappings mappings, InputStream stream, Supplier<String> filenameSupplier) throws IOException, MappingParseException {
+                try (BufferedReader in = new BufferedReader(new InputStreamReader(stream, Charsets.UTF_8))) {
+                        Deque<Object> mappingStack = Queues.newArrayDeque();
 
-                int lineNumber = 0;
-                String line;
-                while ((line = in.readLine()) != null) {
-                        lineNumber++;
+                        int lineNumber = 0;
+                        String line;
+                        while ((line = in.readLine()) != null) {
+                                lineNumber++;
 
-                        // strip comments
-                        int commentPos = line.indexOf('#');
-                        if (commentPos >= 0) {
-                                line = line.substring(0, commentPos);
-                        }
+                                // strip comments
+                                int commentPos = line.indexOf('#');
+                                if (commentPos >= 0) {
+                                        line = line.substring(0, commentPos);
+                                }
 
-                        // skip blank lines
-                        if (line.trim().length() <= 0) {
-                                continue;
-                        }
+                                // skip blank lines
+                                if (line.trim().length() <= 0) {
+                                        continue;
+                                }
 
-                        // get the indent of this line
-                        int indent = 0;
-                        for (int i = 0; i < line.length(); i++) {
-                                if (line.charAt(i) != '\t') {
-                                        break;
+                                // get the indent of this line
+                                int indent = 0;
+                                for (int i = 0; i < line.length(); i++) {
+                                        if (line.charAt(i) != '\t') {
+                                                break;
+                                        }
+                                        indent++;
                                 }
-                                indent++;
-                        }
 
-                        // handle stack pops
-                        while (indent < mappingStack.size()) {
-                                mappingStack.pop();
-                        }
+                                // handle stack pops
+                                while (indent < mappingStack.size()) {
+                                        mappingStack.pop();
+                                }
 
-                        String[] parts = line.trim().split("\\s");
-                        try {
-                                // read the first token
-                                String token = parts[0];
-
-                                if (token.equalsIgnoreCase("CLASS")) {
-                                        ClassMapping classMapping;
-                                        if (indent <= 0) {
-                                                // outer class
-                                                classMapping = readClass(parts, false);
-                                                mappings.addClassMapping(classMapping);
-                                        } else {
-
-                                                // inner class
-                                                if (!(mappingStack.peek() instanceof ClassMapping)) {
-                                                        throw new MappingParseException(file, lineNumber, "Unexpected CLASS entry here!");
+                                String[] parts = line.trim().split("\\s");
+                                try {
+                                        // read the first token
+                                        String token = parts[0];
+
+                                        if (token.equalsIgnoreCase("CLASS")) {
+                                                ClassMapping classMapping;
+                                                if (indent <= 0) {
+                                                        // outer class
+                                                        classMapping = readClass(parts, false);
+                                                        mappings.addClassMapping(classMapping);
+                                                } else {
+
+                                                        // inner class
+                                                        if (!(mappingStack.peek() instanceof ClassMapping)) {
+                                                                throw new MappingParseException(filenameSupplier, lineNumber, "Unexpected CLASS entry here!");
+                                                        }
+
+                                                        classMapping = readClass(parts, true);
+                                                        ((ClassMapping) mappingStack.peek()).addInnerClassMapping(classMapping);
                                                 }
-
-                                                classMapping = readClass(parts, true);
-                                                ((ClassMapping) mappingStack.peek()).addInnerClassMapping(classMapping);
-                                        }
-                                        mappingStack.push(classMapping);
-                                } else if (token.equalsIgnoreCase("FIELD")) {
-                                        if (mappingStack.isEmpty() || !(mappingStack.peek() instanceof ClassMapping)) {
-                                                throw new MappingParseException(file, lineNumber, "Unexpected FIELD entry here!");
-                                        }
-                                        ((ClassMapping) mappingStack.peek()).addFieldMapping(readField(parts));
-                                } else if (token.equalsIgnoreCase("METHOD")) {
-                                        if (mappingStack.isEmpty() || !(mappingStack.peek() instanceof ClassMapping)) {
-                                                throw new MappingParseException(file, lineNumber, "Unexpected METHOD entry here!");
-                                        }
-                                        MethodMapping methodMapping = readMethod(parts);
-                                        ((ClassMapping) mappingStack.peek()).addMethodMapping(methodMapping);
-                                        mappingStack.push(methodMapping);
-                                } else if (token.equalsIgnoreCase("ARG")) {
-                                        if (mappingStack.isEmpty() || !(mappingStack.peek() instanceof MethodMapping)) {
-                                                throw new MappingParseException(file, lineNumber, "Unexpected ARG entry here!");
+                                                mappingStack.push(classMapping);
+                                        } else if (token.equalsIgnoreCase("FIELD")) {
+                                                if (mappingStack.isEmpty() || !(mappingStack.peek() instanceof ClassMapping)) {
+                                                        throw new MappingParseException(filenameSupplier, lineNumber, "Unexpected FIELD entry here!");
+                                                }
+                                                ((ClassMapping) mappingStack.peek()).addFieldMapping(readField(parts));
+                                        } else if (token.equalsIgnoreCase("METHOD")) {
+                                                if (mappingStack.isEmpty() || !(mappingStack.peek() instanceof ClassMapping)) {
+                                                        throw new MappingParseException(filenameSupplier, lineNumber, "Unexpected METHOD entry here!");
+                                                }
+                                                MethodMapping methodMapping = readMethod(parts);
+                                                ((ClassMapping) mappingStack.peek()).addMethodMapping(methodMapping);
+                                                mappingStack.push(methodMapping);
+                                        } else if (token.equalsIgnoreCase("ARG")) {
+                                                if (mappingStack.isEmpty() || !(mappingStack.peek() instanceof MethodMapping)) {
+                                                        throw new MappingParseException(filenameSupplier, lineNumber, "Unexpected ARG entry here!");
+                                                }
+                                                ((MethodMapping) mappingStack.peek()).addArgumentMapping(readArgument(parts));
                                         }
-                                        ((MethodMapping) mappingStack.peek()).addArgumentMapping(readArgument(parts));
+                                } catch (ArrayIndexOutOfBoundsException | IllegalArgumentException ex) {
+                                        throw new MappingParseException(filenameSupplier, lineNumber, "Malformed line:\n" + line);
+                                } catch (MappingConflict e) {
+                                        throw new MappingParseException(filenameSupplier, lineNumber, e.getMessage());
                                 }
-                        } catch (ArrayIndexOutOfBoundsException | IllegalArgumentException ex) {
-                                throw new MappingParseException(file, lineNumber, "Malformed line:\n" + line);
-                        } catch (MappingConflict e) {
-                                throw new MappingParseException(file, lineNumber, e.getMessage());
                         }
+                        return mappings;
                 }
-                in.close();
-                return mappings;
         }
 
-        private ArgumentMapping readArgument(String[] parts) {
-                return new ArgumentMapping(Integer.parseInt(parts[1]), parts[2]);
+        private LocalVariableMapping readArgument(String[] parts) {
+                return new LocalVariableMapping(Integer.parseInt(parts[1]), parts[2]);
         }
 
         private ClassMapping readClass(String[] parts, boolean makeSimple) {
@@ -150,27 +159,27 @@ public class MappingsEnigmaReader {
                 if (parts.length == 4) {
                         boolean access = parts[3].startsWith("ACC:");
                         if (access)
-                                mapping = new FieldMapping(parts[1], new Type(parts[2]), null,
+                                mapping = new FieldMapping(parts[1], new TypeDescriptor(parts[2]), null,
                                         Mappings.EntryModifier.valueOf(parts[3].substring(4)));
                         else
-                                mapping = new FieldMapping(parts[1], new Type(parts[3]), parts[2], Mappings.EntryModifier.UNCHANGED);
+                                mapping = new FieldMapping(parts[1], new TypeDescriptor(parts[3]), parts[2], Mappings.EntryModifier.UNCHANGED);
                 } else if (parts.length == 5)
-                        mapping = new FieldMapping(parts[1], new Type(parts[3]), parts[2], Mappings.EntryModifier.valueOf(parts[4].substring(4)));
+                        mapping = new FieldMapping(parts[1], new TypeDescriptor(parts[3]), parts[2], Mappings.EntryModifier.valueOf(parts[4].substring(4)));
                 return mapping;
         }
 
         private MethodMapping readMethod(String[] parts) {
                 MethodMapping mapping = null;
                 if (parts.length == 3)
-                        mapping = new MethodMapping(parts[1], new Signature(parts[2]));
+                        mapping = new MethodMapping(parts[1], new MethodDescriptor(parts[2]));
                 else if (parts.length == 4) {
                         boolean access = parts[3].startsWith("ACC:");
                         if (access)
-                                mapping = new MethodMapping(parts[1], new Signature(parts[2]), null, Mappings.EntryModifier.valueOf(parts[3].substring(4)));
+                                mapping = new MethodMapping(parts[1], new MethodDescriptor(parts[2]), null, Mappings.EntryModifier.valueOf(parts[3].substring(4)));
                         else
-                                mapping = new MethodMapping(parts[1], new Signature(parts[3]), parts[2]);
+                                mapping = new MethodMapping(parts[1], new MethodDescriptor(parts[3]), parts[2]);
                 } else if (parts.length == 5)
-                        mapping = new MethodMapping(parts[1], new Signature(parts[3]), parts[2],
+                        mapping = new MethodMapping(parts[1], new MethodDescriptor(parts[3]), parts[2],
                                 Mappings.EntryModifier.valueOf(parts[4].substring(4)));
                 return mapping;
         }
diff --git a/src/main/java/cuchaz/enigma/mapping/MappingsEnigmaWriter.java b/src/main/java/cuchaz/enigma/mapping/MappingsEnigmaWriter.java
index ba1b258..b29990f 100644
--- a/src/main/java/cuchaz/enigma/mapping/MappingsEnigmaWriter.java
+++ b/src/main/java/cuchaz/enigma/mapping/MappingsEnigmaWriter.java
@@ -14,9 +14,7 @@ package cuchaz.enigma.mapping;
 import com.google.common.base.Charsets;
 
 import java.io.*;
-import java.util.ArrayList;
-import java.util.Collections;
-import java.util.List;
+import java.util.*;
 
 public class MappingsEnigmaWriter {
 
@@ -33,83 +31,67 @@ public class MappingsEnigmaWriter {
                 if (!target.exists() && !target.mkdirs())
                         throw new IOException("Cannot create mapping directory!");
 
+                Mappings previousState = mappings.getPreviousState();
                 for (ClassMapping classMapping : sorted(mappings.classes())) {
-                        if (!classMapping.isDirty())
+                        if (!classMapping.isDirty()) {
                                 continue;
-                        this.deletePreviousClassMapping(target, classMapping);
-                        File obFile = new File(target, classMapping.getObfFullName() + ".mapping");
-                        File result;
-                        if (classMapping.getDeobfName() == null)
-                                result = obFile;
-                        else {
-                                // Make sure that old version of the file doesn't exist
-                                if (obFile.exists())
-                                        obFile.delete();
-                                result = new File(target, classMapping.getDeobfName() + ".mapping");
                         }
 
-                        if (!result.getParentFile().exists())
-                                result.getParentFile().mkdirs();
+                        if (previousState != null) {
+                                ClassMapping previousClass = previousState.classesByObf.get(classMapping.getObfFullName());
+                                File previousFile;
+                                if (previousClass != null) {
+                                        previousFile = new File(target, previousClass.getSaveName() + ".mapping");
+                                } else {
+                                        previousFile = new File(target, classMapping.getObfFullName() + ".mapping");
+                                }
+                                if (previousFile.exists() && !previousFile.delete()) {
+                                        System.err.println("Failed to delete old class mapping " + previousFile.getName());
+                                }
+                        }
+
+                        File result = new File(target, classMapping.getSaveName() + ".mapping");
+
+                        File packageFile = result.getParentFile();
+                        if (!packageFile.exists()) {
+                                packageFile.mkdirs();
+                        }
                         result.createNewFile();
-                        PrintWriter outputWriter = new PrintWriter(new OutputStreamWriter(new FileOutputStream(result), Charsets.UTF_8));
-                        write(outputWriter, classMapping, 0);
-                        outputWriter.close();
+
+                        try (PrintWriter outputWriter = new PrintWriter(new BufferedWriter(new FileWriter(result)))) {
+                                write(outputWriter, classMapping, 0);
+                        }
                 }
 
                 // Remove dropped mappings
-                if (mappings.getPreviousState() != null) {
-                        List<ClassMapping> droppedClassMappings = new ArrayList<>(mappings.getPreviousState().classes());
-                        List<ClassMapping> classMappings = new ArrayList<>(mappings.classes());
-                        droppedClassMappings.removeAll(classMappings);
-                        for (ClassMapping classMapping : droppedClassMappings) {
-                                File obFile = new File(target, classMapping.getObfFullName() + ".mapping");
-                                File result;
-                                if (classMapping.getDeobfName() == null)
-                                        result = obFile;
-                                else {
-                                        // Make sure that old version of the file doesn't exist
-                                        if (obFile.exists())
-                                                obFile.delete();
-                                        result = new File(target, classMapping.getDeobfName() + ".mapping");
+                if (previousState != null) {
+                        Set<ClassMapping> droppedClassMappings = new HashSet<>(previousState.classes());
+                        droppedClassMappings.removeAll(mappings.classes());
+                        for (ClassMapping droppedMapping : droppedClassMappings) {
+                                File result = new File(target, droppedMapping.getSaveName() + ".mapping");
+                                if (!result.exists()) {
+                                        continue;
+                                }
+                                if (!result.delete()) {
+                                        System.err.println("Failed to delete dropped class mapping " + result.getName());
                                 }
-                                if (result.exists())
-                                        result.delete();
                         }
                 }
         }
 
-        private void deletePreviousClassMapping(File target, ClassMapping classMapping) {
-                File prevFile = null;
-                // Deob rename
-                if (classMapping.getDeobfName() != null && classMapping.getPreviousDeobfName() != null && !classMapping.getPreviousDeobfName().equals(classMapping.getDeobfName())) {
-                        prevFile = new File(target, classMapping.getPreviousDeobfName() + ".mapping");
-                }
-                // Deob to ob rename
-                else if (classMapping.getDeobfName() == null && classMapping.getPreviousDeobfName() != null) {
-                        prevFile = new File(target, classMapping.getPreviousDeobfName() + ".mapping");
-                }
-                // Ob to Deob rename
-                else if (classMapping.getDeobfName() != null && classMapping.getPreviousDeobfName() == null) {
-                        prevFile = new File(target, classMapping.getObfFullName() + ".mapping");
-                }
-
-                if (prevFile != null && prevFile.exists())
-                        prevFile.delete();
-        }
-
         public void write(PrintWriter out, Mappings mappings) throws IOException {
                 for (ClassMapping classMapping : sorted(mappings.classes())) {
                         write(out, classMapping, 0);
                 }
         }
 
-        private void write(PrintWriter out, ClassMapping classMapping, int depth) throws IOException {
+        protected void write(PrintWriter out, ClassMapping classMapping, int depth) throws IOException {
                 if (classMapping.getDeobfName() == null) {
                         out.format("%sCLASS %s%s\n", getIndent(depth), classMapping.getObfFullName(),
-                                classMapping.getModifier() == Mappings.EntryModifier.UNCHANGED ? "" : classMapping.getModifier().getFormattedName());
+                                        classMapping.getModifier() == Mappings.EntryModifier.UNCHANGED ? "" : classMapping.getModifier().getFormattedName());
                 } else {
                         out.format("%sCLASS %s %s%s\n", getIndent(depth), classMapping.getObfFullName(), classMapping.getDeobfName(),
-                                classMapping.getModifier() == Mappings.EntryModifier.UNCHANGED ? "" : classMapping.getModifier().getFormattedName());
+                                        classMapping.getModifier() == Mappings.EntryModifier.UNCHANGED ? "" : classMapping.getModifier().getFormattedName());
                 }
 
                 for (ClassMapping innerClassMapping : sorted(classMapping.innerClasses())) {
@@ -127,32 +109,32 @@ public class MappingsEnigmaWriter {
 
         private void write(PrintWriter out, FieldMapping fieldMapping, int depth) {
                 if (fieldMapping.getDeobfName() == null)
-                        out.format("%sFIELD %s %s%s\n", getIndent(depth), fieldMapping.getObfName(), fieldMapping.getObfType().toString(),
-                                fieldMapping.getModifier() == Mappings.EntryModifier.UNCHANGED ? "" : fieldMapping.getModifier().getFormattedName());
+                        out.format("%sFIELD %s %s%s\n", getIndent(depth), fieldMapping.getObfName(), fieldMapping.getObfDesc().toString(),
+                                        fieldMapping.getModifier() == Mappings.EntryModifier.UNCHANGED ? "" : fieldMapping.getModifier().getFormattedName());
                 else
-                        out.format("%sFIELD %s %s %s%s\n", getIndent(depth), fieldMapping.getObfName(), fieldMapping.getDeobfName(), fieldMapping.getObfType().toString(),
-                                fieldMapping.getModifier() == Mappings.EntryModifier.UNCHANGED ? "" : fieldMapping.getModifier().getFormattedName());
+                        out.format("%sFIELD %s %s %s%s\n", getIndent(depth), fieldMapping.getObfName(), fieldMapping.getDeobfName(), fieldMapping.getObfDesc().toString(),
+                                        fieldMapping.getModifier() == Mappings.EntryModifier.UNCHANGED ? "" : fieldMapping.getModifier().getFormattedName());
         }
 
         private void write(PrintWriter out, MethodMapping methodMapping, int depth) throws IOException {
-                if (methodMapping.getDeobfName() == null) {
-                        out.format("%sMETHOD %s %s%s\n", getIndent(depth), methodMapping.getObfName(), methodMapping.getObfSignature(),
-                                methodMapping.getModifier() == Mappings.EntryModifier.UNCHANGED ? "" : methodMapping.getModifier().getFormattedName());
+                if (methodMapping.isObfuscated()) {
+                        out.format("%sMETHOD %s %s%s\n", getIndent(depth), methodMapping.getObfName(), methodMapping.getObfDesc(),
+                                        methodMapping.getModifier() == Mappings.EntryModifier.UNCHANGED ? "" : methodMapping.getModifier().getFormattedName());
                 } else {
-                        out.format("%sMETHOD %s %s %s%s\n", getIndent(depth), methodMapping.getObfName(), methodMapping.getDeobfName(), methodMapping.getObfSignature(),
-                                methodMapping.getModifier() == Mappings.EntryModifier.UNCHANGED ? "" : methodMapping.getModifier().getFormattedName());
+                        out.format("%sMETHOD %s %s %s%s\n", getIndent(depth), methodMapping.getObfName(), methodMapping.getDeobfName(), methodMapping.getObfDesc(),
+                                        methodMapping.getModifier() == Mappings.EntryModifier.UNCHANGED ? "" : methodMapping.getModifier().getFormattedName());
                 }
 
-                for (ArgumentMapping argumentMapping : sorted(methodMapping.arguments())) {
-                        write(out, argumentMapping, depth + 1);
+                for (LocalVariableMapping localVariableMapping : sorted(methodMapping.arguments())) {
+                        write(out, localVariableMapping, depth + 1);
                 }
         }
 
-        private void write(PrintWriter out, ArgumentMapping argumentMapping, int depth) {
-                out.format("%sARG %d %s\n", getIndent(depth), argumentMapping.getIndex(), argumentMapping.getName());
+        private void write(PrintWriter out, LocalVariableMapping localVariableMapping, int depth) {
+                out.format("%sARG %d %s\n", getIndent(depth), localVariableMapping.getIndex(), localVariableMapping.getName());
         }
 
-        private <T extends Comparable<T>> List<T> sorted(Iterable<T> classes) {
+        protected <T extends Comparable<T>> List<T> sorted(Iterable<T> classes) {
                 List<T> out = new ArrayList<>();
                 for (T t : classes) {
                         out.add(t);
diff --git a/src/main/java/cuchaz/enigma/mapping/MappingsRenamer.java b/src/main/java/cuchaz/enigma/mapping/MappingsRenamer.java
index 7126d2b..85b6d2a 100644
--- a/src/main/java/cuchaz/enigma/mapping/MappingsRenamer.java
+++ b/src/main/java/cuchaz/enigma/mapping/MappingsRenamer.java
@@ -13,6 +13,7 @@ package cuchaz.enigma.mapping;
 
 import com.google.common.collect.Lists;
 import cuchaz.enigma.analysis.JarIndex;
+import cuchaz.enigma.mapping.entry.*;
 import cuchaz.enigma.throwables.IllegalNameException;
 import cuchaz.enigma.throwables.MappingConflict;
 
@@ -25,12 +26,14 @@ import java.util.zip.GZIPOutputStream;
 
 public class MappingsRenamer {
 
-        private JarIndex index;
+        private final JarIndex index;
+        private final ReferencedEntryPool entryPool;
         private Mappings mappings;
 
-        public MappingsRenamer(JarIndex index, Mappings mappings) {
+        public MappingsRenamer(JarIndex index, Mappings mappings, ReferencedEntryPool entryPool) {
                 this.index = index;
                 this.mappings = mappings;
+                this.entryPool = entryPool;
         }
 
         public void setMappings(Mappings mappings) {
@@ -46,7 +49,7 @@ public class MappingsRenamer {
 
                         if (deobfName != null) {
                                 // make sure we don't rename to an existing obf or deobf class
-                                if (mappings.containsDeobfClass(deobfName) || index.containsObfClass(new ClassEntry(deobfName))) {
+                                if (mappings.containsDeobfClass(deobfName) || index.containsObfClass(entryPool.getClass(deobfName))) {
                                         throw new IllegalNameException(deobfName, "There is already a class with that name");
                                 }
                         }
@@ -87,13 +90,13 @@ public class MappingsRenamer {
 
         public void setFieldName(FieldEntry obf, String deobfName) {
                 deobfName = NameValidator.validateFieldName(deobfName);
-                FieldEntry targetEntry = new FieldEntry(obf.getClassEntry(), deobfName, obf.getType());
+                FieldEntry targetEntry = entryPool.getField(obf.getOwnerClassEntry(), deobfName, obf.getDesc());
                 ClassEntry definedClass = null;
-                if (mappings.containsDeobfField(obf.getClassEntry(), deobfName) || index.containsEntryWithSameName(targetEntry))
-                        definedClass = obf.getClassEntry();
+                if (mappings.containsDeobfField(obf.getOwnerClassEntry(), deobfName) || index.containsEntryWithSameName(targetEntry))
+                        definedClass = obf.getOwnerClassEntry();
                 else {
-                        for (ClassEntry ancestorEntry : this.index.getTranslationIndex().getAncestry(obf.getClassEntry())) {
-                                if (mappings.containsDeobfField(ancestorEntry, deobfName) || index.containsEntryWithSameName(targetEntry.cloneToNewClass(ancestorEntry))) {
+                        for (ClassEntry ancestorEntry : this.index.getTranslationIndex().getAncestry(obf.getOwnerClassEntry())) {
+                                if (mappings.containsDeobfField(ancestorEntry, deobfName) || index.containsEntryWithSameName(targetEntry.updateOwnership(ancestorEntry))) {
                                         definedClass = ancestorEntry;
                                         break;
                                 }
@@ -101,42 +104,44 @@ public class MappingsRenamer {
                 }
 
                 if (definedClass != null) {
-                        String className = mappings.getTranslator(TranslationDirection.Deobfuscating, index.getTranslationIndex()).translateClass(definedClass.getClassName());
+                        Translator translator = mappings.getTranslator(TranslationDirection.DEOBFUSCATING, index.getTranslationIndex());
+                        String className = translator.getTranslatedClass(entryPool.getClass(definedClass.getClassName())).getName();
                         if (className == null)
                                 className = definedClass.getClassName();
                         throw new IllegalNameException(deobfName, "There is already a field with that name in " + className);
                 }
 
-                ClassMapping classMapping = getOrCreateClassMapping(obf.getClassEntry());
-                classMapping.setFieldName(obf.getName(), obf.getType(), deobfName);
+                ClassMapping classMapping = getOrCreateClassMapping(obf.getOwnerClassEntry());
+                classMapping.setFieldName(obf.getName(), obf.getDesc(), deobfName);
         }
 
         public void removeFieldMapping(FieldEntry obf) {
-                ClassMapping classMapping = getOrCreateClassMapping(obf.getClassEntry());
-                classMapping.removeFieldMapping(classMapping.getFieldByObf(obf.getName(), obf.getType()));
+                ClassMapping classMapping = getOrCreateClassMapping(obf.getOwnerClassEntry());
+                classMapping.removeFieldMapping(classMapping.getFieldByObf(obf.getName(), obf.getDesc()));
         }
 
         public void markFieldAsDeobfuscated(FieldEntry obf) {
-                ClassMapping classMapping = getOrCreateClassMapping(obf.getClassEntry());
-                classMapping.setFieldName(obf.getName(), obf.getType(), obf.getName());
+                ClassMapping classMapping = getOrCreateClassMapping(obf.getOwnerClassEntry());
+                classMapping.setFieldName(obf.getName(), obf.getDesc(), obf.getName());
         }
 
         private void validateMethodTreeName(MethodEntry entry, String deobfName) {
-                MethodEntry targetEntry = new MethodEntry(entry.getClassEntry(), deobfName, entry.getSignature());
+                MethodEntry targetEntry = entryPool.getMethod(entry.getOwnerClassEntry(), deobfName, entry.getDesc());
 
                 // TODO: Verify if I don't break things
-                ClassMapping classMapping = mappings.getClassByObf(entry.getClassEntry());
-                if ((classMapping != null && classMapping.containsDeobfMethod(deobfName, entry.getSignature()) && classMapping.getMethodByObf(entry.getName(), entry.getSignature()) != classMapping.getMethodByDeobf(deobfName, entry.getSignature()))
-                        || index.containsObfBehavior(targetEntry)) {
-                        String deobfClassName = mappings.getTranslator(TranslationDirection.Deobfuscating, index.getTranslationIndex()).translateClass(entry.getClassName());
+                ClassMapping classMapping = mappings.getClassByObf(entry.getOwnerClassEntry());
+                if ((classMapping != null && classMapping.containsDeobfMethod(deobfName, entry.getDesc()) && classMapping.getMethodByObf(entry.getName(), entry.getDesc()) != classMapping.getMethodByDeobf(deobfName, entry.getDesc()))
+                                || index.containsObfMethod(targetEntry)) {
+                        Translator translator = mappings.getTranslator(TranslationDirection.DEOBFUSCATING, index.getTranslationIndex());
+                        String deobfClassName = translator.getTranslatedClass(entryPool.getClass(entry.getClassName())).getClassName();
                         if (deobfClassName == null) {
                                 deobfClassName = entry.getClassName();
                         }
                         throw new IllegalNameException(deobfName, "There is already a method with that name and signature in class " + deobfClassName);
                 }
 
-                for (ClassEntry child : index.getTranslationIndex().getSubclass(entry.getClassEntry())) {
-                        validateMethodTreeName(entry.cloneToNewClass(child), deobfName);
+                for (ClassEntry child : index.getTranslationIndex().getSubclass(entry.getOwnerClassEntry())) {
+                        validateMethodTreeName(entry.updateOwnership(child), deobfName);
                 }
         }
 
@@ -155,20 +160,21 @@ public class MappingsRenamer {
 
         public void setMethodName(MethodEntry obf, String deobfName) {
                 deobfName = NameValidator.validateMethodName(deobfName);
-                MethodEntry targetEntry = new MethodEntry(obf.getClassEntry(), deobfName, obf.getSignature());
-                ClassMapping classMapping = getOrCreateClassMapping(obf.getClassEntry());
+                MethodEntry targetEntry = entryPool.getMethod(obf.getOwnerClassEntry(), deobfName, obf.getDesc());
+                ClassMapping classMapping = getOrCreateClassMapping(obf.getOwnerClassEntry());
 
                 // TODO: Verify if I don't break things
-                if ((mappings.containsDeobfMethod(obf.getClassEntry(), deobfName, obf.getSignature()) && classMapping.getMethodByObf(obf.getName(), obf.getSignature()) != classMapping.getMethodByDeobf(deobfName, obf.getSignature()))
-                        || index.containsObfBehavior(targetEntry)) {
-                        String deobfClassName = mappings.getTranslator(TranslationDirection.Deobfuscating, index.getTranslationIndex()).translateClass(obf.getClassName());
+                if ((mappings.containsDeobfMethod(obf.getOwnerClassEntry(), deobfName, obf.getDesc()) && classMapping.getMethodByObf(obf.getName(), obf.getDesc()) != classMapping.getMethodByDeobf(deobfName, obf.getDesc()))
+                                || index.containsObfMethod(targetEntry)) {
+                        Translator translator = mappings.getTranslator(TranslationDirection.DEOBFUSCATING, index.getTranslationIndex());
+                        String deobfClassName = translator.getTranslatedClass(entryPool.getClass(obf.getClassName())).getClassName();
                         if (deobfClassName == null) {
                                 deobfClassName = obf.getClassName();
                         }
                         throw new IllegalNameException(deobfName, "There is already a method with that name and signature in class " + deobfClassName);
                 }
 
-                classMapping.setMethodName(obf.getName(), obf.getSignature(), deobfName);
+                classMapping.setMethodName(obf.getName(), obf.getDesc(), deobfName);
         }
 
         public void removeMethodTreeMapping(MethodEntry obf) {
@@ -176,8 +182,8 @@ public class MappingsRenamer {
         }
 
         public void removeMethodMapping(MethodEntry obf) {
-                ClassMapping classMapping = getOrCreateClassMapping(obf.getClassEntry());
-                classMapping.setMethodName(obf.getName(), obf.getSignature(), null);
+                ClassMapping classMapping = getOrCreateClassMapping(obf.getOwnerClassEntry());
+                classMapping.setMethodName(obf.getName(), obf.getDesc(), null);
         }
 
         public void markMethodTreeAsDeobfuscated(MethodEntry obf) {
@@ -185,30 +191,25 @@ public class MappingsRenamer {
         }
 
         public void markMethodAsDeobfuscated(MethodEntry obf) {
-                ClassMapping classMapping = getOrCreateClassMapping(obf.getClassEntry());
-                classMapping.setMethodName(obf.getName(), obf.getSignature(), obf.getName());
+                ClassMapping classMapping = getOrCreateClassMapping(obf.getOwnerClassEntry());
+                classMapping.setMethodName(obf.getName(), obf.getDesc(), obf.getName());
         }
 
-        public void setArgumentTreeName(ArgumentEntry obf, String deobfName) {
-                if (!(obf.getBehaviorEntry() instanceof MethodEntry)) {
-                        setArgumentName(obf, deobfName);
-                        return;
-                }
-
-                MethodEntry obfMethod = (MethodEntry) obf.getBehaviorEntry();
+        public void setLocalVariableTreeName(LocalVariableEntry obf, String deobfName) {
+                MethodEntry obfMethod = obf.getOwnerEntry();
 
                 Set<MethodEntry> implementations = index.getRelatedMethodImplementations(obfMethod);
                 for (MethodEntry entry : implementations) {
-                        ClassMapping classMapping = mappings.getClassByObf(entry.getClassEntry());
+                        ClassMapping classMapping = mappings.getClassByObf(entry.getOwnerClassEntry());
                         if (classMapping != null) {
-                                MethodMapping mapping = classMapping.getMethodByObf(entry.getName(), entry.getSignature());
+                                MethodMapping mapping = classMapping.getMethodByObf(entry.getName(), entry.getDesc());
                                 // NOTE: don't need to check arguments for name collisions with names determined by Procyon
                                 // TODO: Verify if I don't break things
                                 if (mapping != null) {
-                                        for (ArgumentMapping argumentMapping : Lists.newArrayList(mapping.arguments())) {
-                                                if (argumentMapping.getIndex() != obf.getIndex()) {
-                                                        if (mapping.getDeobfArgumentName(argumentMapping.getIndex()).equals(deobfName)
-                                                                || argumentMapping.getName().equals(deobfName)) {
+                                        for (LocalVariableMapping localVariableMapping : Lists.newArrayList(mapping.arguments())) {
+                                                if (localVariableMapping.getIndex() != obf.getIndex()) {
+                                                        if (mapping.getDeobfLocalVariableName(localVariableMapping.getIndex()).equals(deobfName)
+                                                                        || localVariableMapping.getName().equals(deobfName)) {
                                                                 throw new IllegalNameException(deobfName, "There is already an argument with that name");
                                                         }
                                                 }
@@ -218,45 +219,45 @@ public class MappingsRenamer {
                 }
 
                 for (MethodEntry entry : implementations) {
-                        setArgumentName(new ArgumentEntry(obf, entry), deobfName);
+                        setLocalVariableName(new LocalVariableEntry(entry, obf.getIndex(), obf.getName()), deobfName);
                 }
         }
 
-        public void setArgumentName(ArgumentEntry obf, String deobfName) {
+        public void setLocalVariableName(LocalVariableEntry obf, String deobfName) {
                 deobfName = NameValidator.validateArgumentName(deobfName);
-                ClassMapping classMapping = getOrCreateClassMapping(obf.getClassEntry());
-                MethodMapping mapping = classMapping.getMethodByObf(obf.getMethodName(), obf.getMethodSignature());
+                ClassMapping classMapping = getOrCreateClassMapping(obf.getOwnerClassEntry());
+                MethodMapping mapping = classMapping.getMethodByObf(obf.getMethodName(), obf.getMethodDesc());
                 // NOTE: don't need to check arguments for name collisions with names determined by Procyon
                 // TODO: Verify if I don't break things
                 if (mapping != null) {
-                        for (ArgumentMapping argumentMapping : Lists.newArrayList(mapping.arguments())) {
-                                if (argumentMapping.getIndex() != obf.getIndex()) {
-                                        if (mapping.getDeobfArgumentName(argumentMapping.getIndex()).equals(deobfName)
-                                                || argumentMapping.getName().equals(deobfName)) {
+                        for (LocalVariableMapping localVariableMapping : Lists.newArrayList(mapping.arguments())) {
+                                if (localVariableMapping.getIndex() != obf.getIndex()) {
+                                        if (mapping.getDeobfLocalVariableName(localVariableMapping.getIndex()).equals(deobfName)
+                                                        || localVariableMapping.getName().equals(deobfName)) {
                                                 throw new IllegalNameException(deobfName, "There is already an argument with that name");
                                         }
                                 }
                         }
                 }
 
-                classMapping.setArgumentName(obf.getMethodName(), obf.getMethodSignature(), obf.getIndex(), deobfName);
+                classMapping.setArgumentName(obf.getMethodName(), obf.getMethodDesc(), obf.getIndex(), deobfName);
         }
 
-        public void removeArgumentMapping(ArgumentEntry obf) {
-                ClassMapping classMapping = getOrCreateClassMapping(obf.getClassEntry());
-                classMapping.removeArgumentName(obf.getMethodName(), obf.getMethodSignature(), obf.getIndex());
+        public void removeLocalVariableMapping(LocalVariableEntry obf) {
+                ClassMapping classMapping = getOrCreateClassMapping(obf.getOwnerClassEntry());
+                classMapping.removeArgumentName(obf.getMethodName(), obf.getMethodDesc(), obf.getIndex());
         }
 
-        public void markArgumentAsDeobfuscated(ArgumentEntry obf) {
-                ClassMapping classMapping = getOrCreateClassMapping(obf.getClassEntry());
-                classMapping.setArgumentName(obf.getMethodName(), obf.getMethodSignature(), obf.getIndex(), obf.getName());
+        public void markArgumentAsDeobfuscated(LocalVariableEntry obf) {
+                ClassMapping classMapping = getOrCreateClassMapping(obf.getOwnerClassEntry());
+                classMapping.setArgumentName(obf.getMethodName(), obf.getMethodDesc(), obf.getIndex(), obf.getName());
         }
 
         public boolean moveFieldToObfClass(ClassMapping classMapping, FieldMapping fieldMapping, ClassEntry obfClass) {
                 classMapping.removeFieldMapping(fieldMapping);
                 ClassMapping targetClassMapping = getOrCreateClassMapping(obfClass);
-                if (!targetClassMapping.containsObfField(fieldMapping.getObfName(), fieldMapping.getObfType())) {
-                        if (!targetClassMapping.containsDeobfField(fieldMapping.getDeobfName(), fieldMapping.getObfType())) {
+                if (!targetClassMapping.containsObfField(fieldMapping.getObfName(), fieldMapping.getObfDesc())) {
+                        if (!targetClassMapping.containsDeobfField(fieldMapping.getDeobfName(), fieldMapping.getObfDesc())) {
                                 targetClassMapping.addFieldMapping(fieldMapping);
                                 return true;
                         } else {
@@ -269,12 +270,12 @@ public class MappingsRenamer {
         public boolean moveMethodToObfClass(ClassMapping classMapping, MethodMapping methodMapping, ClassEntry obfClass) {
                 classMapping.removeMethodMapping(methodMapping);
                 ClassMapping targetClassMapping = getOrCreateClassMapping(obfClass);
-                if (!targetClassMapping.containsObfMethod(methodMapping.getObfName(), methodMapping.getObfSignature())) {
-                        if (!targetClassMapping.containsDeobfMethod(methodMapping.getDeobfName(), methodMapping.getObfSignature())) {
+                if (!targetClassMapping.containsObfMethod(methodMapping.getObfName(), methodMapping.getObfDesc())) {
+                        if (!targetClassMapping.containsDeobfMethod(methodMapping.getDeobfName(), methodMapping.getObfDesc())) {
                                 targetClassMapping.addMethodMapping(methodMapping);
                                 return true;
                         } else {
-                                System.err.println("WARNING: deobf method was already there: " + obfClass + "." + methodMapping.getDeobfName() + methodMapping.getObfSignature());
+                                System.err.println("WARNING: deobf method was already there: " + obfClass + "." + methodMapping.getDeobfName() + methodMapping.getObfDesc());
                         }
                 }
                 return false;
@@ -326,12 +327,35 @@ public class MappingsRenamer {
         }
 
         public void setFieldModifier(FieldEntry obEntry, Mappings.EntryModifier modifier) {
-                ClassMapping classMapping = getOrCreateClassMapping(obEntry.getClassEntry());
-                classMapping.setFieldModifier(obEntry.getName(), obEntry.getType(), modifier);
+                ClassMapping classMapping = getOrCreateClassMapping(obEntry.getOwnerClassEntry());
+                classMapping.setFieldModifier(obEntry.getName(), obEntry.getDesc(), modifier);
+        }
+
+        public void setMethodModifier(MethodEntry obEntry, Mappings.EntryModifier modifier) {
+                ClassMapping classMapping = getOrCreateClassMapping(obEntry.getOwnerClassEntry());
+                classMapping.setMethodModifier(obEntry.getName(), obEntry.getDesc(), modifier);
+        }
+
+        public Mappings.EntryModifier getClassModifier(ClassEntry obfEntry) {
+                ClassMapping classMapping = getOrCreateClassMapping(obfEntry);
+                return classMapping.getModifier();
         }
 
-        public void setMethodModifier(BehaviorEntry obEntry, Mappings.EntryModifier modifier) {
-                ClassMapping classMapping = getOrCreateClassMapping(obEntry.getClassEntry());
-                classMapping.setMethodModifier(obEntry.getName(), obEntry.getSignature(), modifier);
+        public Mappings.EntryModifier getFieldModifier(FieldEntry obfEntry) {
+                ClassMapping classMapping = getOrCreateClassMapping(obfEntry.getOwnerClassEntry());
+                FieldMapping fieldMapping = classMapping.getFieldByObf(obfEntry);
+                if (fieldMapping == null) {
+                        return Mappings.EntryModifier.UNCHANGED;
+                }
+                return fieldMapping.getModifier();
+        }
+
+        public Mappings.EntryModifier getMethodModfifier(MethodEntry obfEntry) {
+                ClassMapping classMapping = getOrCreateClassMapping(obfEntry.getOwnerClassEntry());
+                MethodMapping methodMapping = classMapping.getMethodByObf(obfEntry);
+                if (methodMapping == null) {
+                        return Mappings.EntryModifier.UNCHANGED;
+                }
+                return methodMapping.getModifier();
         }
 }
diff --git a/src/main/java/cuchaz/enigma/mapping/MappingsSRGWriter.java b/src/main/java/cuchaz/enigma/mapping/MappingsSRGWriter.java
index b0eb826..32f0ee9 100644
--- a/src/main/java/cuchaz/enigma/mapping/MappingsSRGWriter.java
+++ b/src/main/java/cuchaz/enigma/mapping/MappingsSRGWriter.java
@@ -2,6 +2,7 @@ package cuchaz.enigma.mapping;
 
 import com.google.common.base.Charsets;
 import cuchaz.enigma.analysis.TranslationIndex;
+import cuchaz.enigma.mapping.entry.ReferencedEntryPool;
 
 import java.io.*;
 import java.util.ArrayList;
@@ -19,7 +20,7 @@ public class MappingsSRGWriter {
                 }
                 file.createNewFile();
 
-                TranslationIndex index = new TranslationIndex();
+                TranslationIndex index = new TranslationIndex(new ReferencedEntryPool());
 
                 PrintWriter writer = new PrintWriter(new OutputStreamWriter(new FileOutputStream(file), Charsets.UTF_8));
                 List<String> fieldMappings = new ArrayList<>();
@@ -43,7 +44,7 @@ public class MappingsSRGWriter {
                                 }
 
                                 for (MethodMapping methodMapping : sorted(innerClassMapping.methods())) {
-                                        methodMappings.add("MD: " + innerClassName + "/" + methodMapping.getObfName() + " " + methodMapping.getObfSignature() + " " + innerDeobfClassName + "/" + methodMapping.getDeobfName() + " " + mappings.getTranslator(TranslationDirection.Deobfuscating, index).translateSignature(methodMapping.getObfSignature()));
+                                        methodMappings.add("MD: " + innerClassName + "/" + methodMapping.getObfName() + " " + methodMapping.getObfDesc() + " " + innerDeobfClassName + "/" + methodMapping.getDeobfName() + " " + mappings.getTranslator(TranslationDirection.DEOBFUSCATING, index).getTranslatedMethodDesc(methodMapping.getObfDesc()));
                                 }
                         }
 
@@ -52,7 +53,7 @@ public class MappingsSRGWriter {
                         }
 
                         for (MethodMapping methodMapping : sorted(classMapping.methods())) {
-                                methodMappings.add("MD: " + classMapping.getObfFullName() + "/" + methodMapping.getObfName() + " " + methodMapping.getObfSignature() + " " + classMapping.getDeobfName() + "/" + methodMapping.getDeobfName() + " " + mappings.getTranslator(TranslationDirection.Deobfuscating, index).translateSignature(methodMapping.getObfSignature()));
+                                methodMappings.add("MD: " + classMapping.getObfFullName() + "/" + methodMapping.getObfName() + " " + methodMapping.getObfDesc() + " " + classMapping.getDeobfName() + "/" + methodMapping.getDeobfName() + " " + mappings.getTranslator(TranslationDirection.DEOBFUSCATING, index).getTranslatedMethodDesc(methodMapping.getObfDesc()));
                         }
                 }
                 for (String fd : fieldMappings) {
diff --git a/src/main/java/cuchaz/enigma/mapping/MappingsTinyReader.java b/src/main/java/cuchaz/enigma/mapping/MappingsTinyReader.java
index befc92a..69d5684 100644
--- a/src/main/java/cuchaz/enigma/mapping/MappingsTinyReader.java
+++ b/src/main/java/cuchaz/enigma/mapping/MappingsTinyReader.java
@@ -2,6 +2,7 @@ package cuchaz.enigma.mapping;
 
 import com.google.common.base.Charsets;
 import com.google.common.collect.Maps;
+import cuchaz.enigma.mapping.entry.ClassEntry;
 import cuchaz.enigma.throwables.MappingConflict;
 import cuchaz.enigma.throwables.MappingParseException;
 
@@ -20,11 +21,11 @@ public class MappingsTinyReader {
         }
 
         public FieldMapping readField(String[] parts) {
-                return new FieldMapping(parts[3], new Type(parts[2]), parts[4], Mappings.EntryModifier.UNCHANGED);
+                return new FieldMapping(parts[3], new TypeDescriptor(parts[2]), parts[4], Mappings.EntryModifier.UNCHANGED);
         }
 
         public MethodMapping readMethod(String[] parts) {
-                return new MethodMapping(parts[3], new Signature(parts[2]), parts[4]);
+                return new MethodMapping(parts[3], new MethodDescriptor(parts[2]), parts[4]);
         }
 
         public Mappings read(File file) throws IOException, MappingParseException {
@@ -72,7 +73,7 @@ public class MappingsTinyReader {
                                                 break;
                                         case "MTH-ARG":
                                                 classMapping = classMappingMap.computeIfAbsent(parts[1], k -> new ClassMapping(parts[1]));
-                                                classMapping.setArgumentName(parts[3], new Signature(parts[2]), Integer.parseInt(parts[4]), parts[5]);
+                                                classMapping.setArgumentName(parts[3], new MethodDescriptor(parts[2]), Integer.parseInt(parts[4]), parts[5]);
                                                 break;
                                         default:
                                                 throw new MappingParseException(file, lineNumber, "Unknown token '" + token + "' !");
diff --git a/src/main/java/cuchaz/enigma/mapping/MemberMapping.java b/src/main/java/cuchaz/enigma/mapping/MemberMapping.java
index d4514d4..6effb91 100644
--- a/src/main/java/cuchaz/enigma/mapping/MemberMapping.java
+++ b/src/main/java/cuchaz/enigma/mapping/MemberMapping.java
@@ -11,6 +11,9 @@
 
 package cuchaz.enigma.mapping;
 
+import cuchaz.enigma.mapping.entry.ClassEntry;
+import cuchaz.enigma.mapping.entry.Entry;
+
 public interface MemberMapping<T extends Entry> {
         T getObfEntry(ClassEntry classEntry);
 
diff --git a/src/main/java/cuchaz/enigma/mapping/MethodDescriptor.java b/src/main/java/cuchaz/enigma/mapping/MethodDescriptor.java
new file mode 100644
index 0000000..0fc0351
--- /dev/null
+++ b/src/main/java/cuchaz/enigma/mapping/MethodDescriptor.java
@@ -0,0 +1,114 @@
+/*******************************************************************************
+ * Copyright (c) 2015 Jeff Martin.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Lesser General Public
+ * License v3.0 which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/lgpl.html
+ * <p>
+ * Contributors:
+ * Jeff Martin - initial API and implementation
+ ******************************************************************************/
+
+package cuchaz.enigma.mapping;
+
+import com.google.common.collect.Lists;
+import cuchaz.enigma.mapping.entry.ClassEntry;
+import cuchaz.enigma.utils.Utils;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.function.Function;
+
+public class MethodDescriptor {
+
+        private List<TypeDescriptor> argumentDescs;
+        private TypeDescriptor returnDesc;
+
+        public MethodDescriptor(String desc) {
+                try {
+                        this.argumentDescs = Lists.newArrayList();
+                        int i = 0;
+                        while (i < desc.length()) {
+                                char c = desc.charAt(i);
+                                if (c == '(') {
+                                        assert (this.argumentDescs.isEmpty());
+                                        assert (this.returnDesc == null);
+                                        i++;
+                                } else if (c == ')') {
+                                        i++;
+                                        break;
+                                } else {
+                                        String type = TypeDescriptor.parseFirst(desc.substring(i));
+                                        this.argumentDescs.add(new TypeDescriptor(type));
+                                        i += type.length();
+                                }
+                        }
+                        this.returnDesc = new TypeDescriptor(TypeDescriptor.parseFirst(desc.substring(i)));
+                } catch (Exception ex) {
+                        throw new IllegalArgumentException("Unable to parse method descriptor: " + desc, ex);
+                }
+        }
+
+        public MethodDescriptor(List<TypeDescriptor> argumentDescs, TypeDescriptor returnDesc) {
+                this.argumentDescs = argumentDescs;
+                this.returnDesc = returnDesc;
+        }
+
+        public List<TypeDescriptor> getArgumentDescs() {
+                return this.argumentDescs;
+        }
+
+        public TypeDescriptor getReturnDesc() {
+                return this.returnDesc;
+        }
+
+        @Override
+        public String toString() {
+                StringBuilder buf = new StringBuilder();
+                buf.append("(");
+                for (TypeDescriptor desc : this.argumentDescs) {
+                        buf.append(desc);
+                }
+                buf.append(")");
+                buf.append(this.returnDesc);
+                return buf.toString();
+        }
+
+        public Iterable<TypeDescriptor> types() {
+                List<TypeDescriptor> descs = Lists.newArrayList();
+                descs.addAll(this.argumentDescs);
+                descs.add(this.returnDesc);
+                return descs;
+        }
+
+        @Override
+        public boolean equals(Object other) {
+                return other instanceof MethodDescriptor && equals((MethodDescriptor) other);
+        }
+
+        public boolean equals(MethodDescriptor other) {
+                return this.argumentDescs.equals(other.argumentDescs) && this.returnDesc.equals(other.returnDesc);
+        }
+
+        @Override
+        public int hashCode() {
+                return Utils.combineHashesOrdered(this.argumentDescs.hashCode(), this.returnDesc.hashCode());
+        }
+
+        public boolean hasClass(ClassEntry classEntry) {
+                for (TypeDescriptor desc : types()) {
+                        if (desc.containsType() && desc.getTypeEntry().equals(classEntry)) {
+                                return true;
+                        }
+                }
+                return false;
+        }
+
+        public MethodDescriptor remap(Function<String, String> remapper) {
+                List<TypeDescriptor> argumentDescs = new ArrayList<>(this.argumentDescs.size());
+                for (TypeDescriptor desc : this.argumentDescs) {
+                        argumentDescs.add(desc.remap(remapper));
+                }
+                return new MethodDescriptor(argumentDescs, returnDesc.remap(remapper));
+        }
+}
diff --git a/src/main/java/cuchaz/enigma/mapping/MethodEntry.java b/src/main/java/cuchaz/enigma/mapping/MethodEntry.java
deleted file mode 100644
index 9c3058c..0000000
--- a/src/main/java/cuchaz/enigma/mapping/MethodEntry.java
+++ /dev/null
@@ -1,90 +0,0 @@
-/*******************************************************************************
- * Copyright (c) 2015 Jeff Martin.
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Lesser General Public
- * License v3.0 which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/lgpl.html
- * <p>
- * Contributors:
- * Jeff Martin - initial API and implementation
- ******************************************************************************/
-
-package cuchaz.enigma.mapping;
-
-import cuchaz.enigma.utils.Utils;
-
-public class MethodEntry implements BehaviorEntry {
-
-        private ClassEntry classEntry;
-        private String name;
-        private Signature signature;
-
-        public MethodEntry(ClassEntry classEntry, String name, Signature signature) {
-                if (classEntry == null) {
-                        throw new IllegalArgumentException("Class cannot be null!");
-                }
-                if (name == null) {
-                        throw new IllegalArgumentException("Method name cannot be null!");
-                }
-                if (signature == null) {
-                        throw new IllegalArgumentException("Method signature cannot be null!");
-                }
-                if (name.startsWith("<")) {
-                        throw new IllegalArgumentException("Don't use MethodEntry for a constructor!");
-                }
-
-                this.classEntry = classEntry;
-                this.name = name;
-                this.signature = signature;
-        }
-
-        public MethodEntry(MethodEntry other, String newClassName) {
-                this.classEntry = new ClassEntry(newClassName);
-                this.name = other.name;
-                this.signature = other.signature;
-        }
-
-        @Override
-        public ClassEntry getClassEntry() {
-                return this.classEntry;
-        }
-
-        @Override
-        public String getName() {
-                return this.name;
-        }
-
-        @Override
-        public Signature getSignature() {
-                return this.signature;
-        }
-
-        @Override
-        public String getClassName() {
-                return this.classEntry.getName();
-        }
-
-        @Override
-        public MethodEntry cloneToNewClass(ClassEntry classEntry) {
-                return new MethodEntry(this, classEntry.getName());
-        }
-
-        @Override
-        public int hashCode() {
-                return Utils.combineHashesOrdered(this.classEntry, this.name, this.signature);
-        }
-
-        @Override
-        public boolean equals(Object other) {
-                return other instanceof MethodEntry && equals((MethodEntry) other);
-        }
-
-        public boolean equals(MethodEntry other) {
-                return this.classEntry.equals(other.classEntry) && this.name.equals(other.name) && this.signature.equals(other.signature);
-        }
-
-        @Override
-        public String toString() {
-                return this.classEntry.getName() + "." + this.name + this.signature;
-        }
-}
diff --git a/src/main/java/cuchaz/enigma/mapping/MethodMapping.java b/src/main/java/cuchaz/enigma/mapping/MethodMapping.java
index 1524ce6..2f10144 100644
--- a/src/main/java/cuchaz/enigma/mapping/MethodMapping.java
+++ b/src/main/java/cuchaz/enigma/mapping/MethodMapping.java
@@ -11,50 +11,49 @@
 
 package cuchaz.enigma.mapping;
 
+import com.google.common.base.Preconditions;
 import com.google.common.collect.Maps;
+import cuchaz.enigma.mapping.entry.ClassEntry;
+import cuchaz.enigma.mapping.entry.MethodEntry;
 import cuchaz.enigma.throwables.IllegalNameException;
 import cuchaz.enigma.throwables.MappingConflict;
 
 import java.util.Map;
 
-public class MethodMapping implements Comparable<MethodMapping>, MemberMapping<BehaviorEntry> {
+public class MethodMapping implements Comparable<MethodMapping>, MemberMapping<MethodEntry> {
 
         private String obfName;
         private String deobfName;
-        private Signature obfSignature;
-        private Map<Integer, ArgumentMapping> arguments;
+        private MethodDescriptor obfDescriptor;
+        private Map<Integer, LocalVariableMapping> localVariables;
         private Mappings.EntryModifier modifier;
 
-        public MethodMapping(String obfName, Signature obfSignature) {
-                this(obfName, obfSignature, null, Mappings.EntryModifier.UNCHANGED);
+        public MethodMapping(String obfName, MethodDescriptor obfDescriptor) {
+                this(obfName, obfDescriptor, null, Mappings.EntryModifier.UNCHANGED);
         }
 
-        public MethodMapping(String obfName, Signature obfSignature, String deobfName) {
-                this(obfName, obfSignature, deobfName, Mappings.EntryModifier.UNCHANGED);
+        public MethodMapping(String obfName, MethodDescriptor obfDescriptor, String deobfName) {
+                this(obfName, obfDescriptor, deobfName, Mappings.EntryModifier.UNCHANGED);
         }
 
-        public MethodMapping(String obfName, Signature obfSignature, String deobfName, Mappings.EntryModifier modifier) {
-                if (obfName == null) {
-                        throw new IllegalArgumentException("obf name cannot be null!");
-                }
-                if (obfSignature == null) {
-                        throw new IllegalArgumentException("obf signature cannot be null!");
-                }
+        public MethodMapping(String obfName, MethodDescriptor obfDescriptor, String deobfName, Mappings.EntryModifier modifier) {
+                Preconditions.checkNotNull(obfName, "Method obf name cannot be null");
+                Preconditions.checkNotNull(obfDescriptor, "Method obf desc cannot be null");
                 this.obfName = obfName;
                 this.deobfName = NameValidator.validateMethodName(deobfName);
-                this.obfSignature = obfSignature;
-                this.arguments = Maps.newTreeMap();
+                this.obfDescriptor = obfDescriptor;
+                this.localVariables = Maps.newTreeMap();
                 this.modifier = modifier;
         }
 
-        public MethodMapping(MethodMapping other, ClassNameReplacer obfClassNameReplacer) {
+        public MethodMapping(MethodMapping other, Translator translator) {
                 this.obfName = other.obfName;
                 this.deobfName = other.deobfName;
                 this.modifier = other.modifier;
-                this.obfSignature = new Signature(other.obfSignature, obfClassNameReplacer);
-                this.arguments = Maps.newTreeMap();
-                for (Map.Entry<Integer, ArgumentMapping> entry : other.arguments.entrySet()) {
-                        this.arguments.put(entry.getKey(), new ArgumentMapping(entry.getValue()));
+                this.obfDescriptor = translator.getTranslatedMethodDesc(other.obfDescriptor);
+                this.localVariables = Maps.newTreeMap();
+                for (Map.Entry<Integer, LocalVariableMapping> entry : other.localVariables.entrySet()) {
+                        this.localVariables.put(entry.getKey(), new LocalVariableMapping(entry.getValue()));
                 }
         }
 
@@ -77,6 +76,9 @@ public class MethodMapping implements Comparable<MethodMapping>, MemberMapping<B
         }
 
         public String getDeobfName() {
+                if (deobfName == null) {
+                        return obfName;
+                }
                 return this.deobfName;
         }
 
@@ -84,56 +86,56 @@ public class MethodMapping implements Comparable<MethodMapping>, MemberMapping<B
                 this.deobfName = NameValidator.validateMethodName(val);
         }
 
-        public Signature getObfSignature() {
-                return this.obfSignature;
+        public MethodDescriptor getObfDesc() {
+                return this.obfDescriptor;
         }
 
-        public void setObfSignature(Signature val) {
-                this.obfSignature = val;
+        public void setObfDescriptor(MethodDescriptor val) {
+                this.obfDescriptor = val;
         }
 
-        public Iterable<ArgumentMapping> arguments() {
-                return this.arguments.values();
+        public Iterable<LocalVariableMapping> arguments() {
+                return this.localVariables.values();
         }
 
-        public void addArgumentMapping(ArgumentMapping argumentMapping) throws MappingConflict {
-                if (this.arguments.containsKey(argumentMapping.getIndex())) {
-                        throw new MappingConflict("argument", argumentMapping.getName(), this.arguments.get(argumentMapping.getIndex()).getName());
+        public void addArgumentMapping(LocalVariableMapping localVariableMapping) throws MappingConflict {
+                if (this.localVariables.containsKey(localVariableMapping.getIndex())) {
+                        throw new MappingConflict("argument", localVariableMapping.getName(), this.localVariables.get(localVariableMapping.getIndex()).getName());
                 }
-                this.arguments.put(argumentMapping.getIndex(), argumentMapping);
+                this.localVariables.put(localVariableMapping.getIndex(), localVariableMapping);
         }
 
-        public String getObfArgumentName(int index) {
-                ArgumentMapping argumentMapping = this.arguments.get(index);
-                if (argumentMapping != null) {
-                        return argumentMapping.getName();
+        public String getObfLocalVariableName(int index) {
+                LocalVariableMapping localVariableMapping = this.localVariables.get(index);
+                if (localVariableMapping != null) {
+                        return localVariableMapping.getName();
                 }
 
                 return null;
         }
 
-        public String getDeobfArgumentName(int index) {
-                ArgumentMapping argumentMapping = this.arguments.get(index);
-                if (argumentMapping != null) {
-                        return argumentMapping.getName();
+        public String getDeobfLocalVariableName(int index) {
+                LocalVariableMapping localVariableMapping = this.localVariables.get(index);
+                if (localVariableMapping != null) {
+                        return localVariableMapping.getName();
                 }
 
                 return null;
         }
 
-        public void setArgumentName(int index, String name) {
-                ArgumentMapping argumentMapping = this.arguments.get(index);
-                if (argumentMapping == null) {
-                        argumentMapping = new ArgumentMapping(index, name);
-                        boolean wasAdded = this.arguments.put(index, argumentMapping) == null;
+        public void setLocalVariableName(int index, String name) {
+                LocalVariableMapping localVariableMapping = this.localVariables.get(index);
+                if (localVariableMapping == null) {
+                        localVariableMapping = new LocalVariableMapping(index, name);
+                        boolean wasAdded = this.localVariables.put(index, localVariableMapping) == null;
                         assert (wasAdded);
                 } else {
-                        argumentMapping.setName(name);
+                        localVariableMapping.setName(name);
                 }
         }
 
-        public void removeArgumentName(int index) {
-                boolean wasRemoved = this.arguments.remove(index) != null;
+        public void removeLocalVariableName(int index) {
+                boolean wasRemoved = this.localVariables.remove(index) != null;
                 assert (wasRemoved);
         }
 
@@ -146,14 +148,14 @@ public class MethodMapping implements Comparable<MethodMapping>, MemberMapping<B
                 buf.append(this.deobfName);
                 buf.append("\n");
                 buf.append("\t");
-                buf.append(this.obfSignature);
+                buf.append(this.obfDescriptor);
                 buf.append("\n");
-                buf.append("\tArguments:\n");
-                for (ArgumentMapping argumentMapping : this.arguments.values()) {
+                buf.append("\tLocal Variables:\n");
+                for (LocalVariableMapping localVariableMapping : this.localVariables.values()) {
                         buf.append("\t\t");
-                        buf.append(argumentMapping.getIndex());
+                        buf.append(localVariableMapping.getIndex());
                         buf.append(" -> ");
-                        buf.append(argumentMapping.getName());
+                        buf.append(localVariableMapping.getName());
                         buf.append("\n");
                 }
                 return buf.toString();
@@ -161,12 +163,12 @@ public class MethodMapping implements Comparable<MethodMapping>, MemberMapping<B
 
         @Override
         public int compareTo(MethodMapping other) {
-                return (this.obfName + this.obfSignature).compareTo(other.obfName + other.obfSignature);
+                return (this.obfName + this.obfDescriptor).compareTo(other.obfName + other.obfDescriptor);
         }
 
-        public boolean containsArgument(String name) {
-                for (ArgumentMapping argumentMapping : this.arguments.values()) {
-                        if (argumentMapping.getName().equals(name)) {
+        public boolean containsLocalVariable(String name) {
+                for (LocalVariableMapping localVariableMapping : this.localVariables.values()) {
+                        if (localVariableMapping.getName().equals(name)) {
                                 return true;
                         }
                 }
@@ -175,32 +177,23 @@ public class MethodMapping implements Comparable<MethodMapping>, MemberMapping<B
 
         public boolean renameObfClass(final String oldObfClassName, final String newObfClassName) {
                 // rename obf classes in the signature
-                Signature newSignature = new Signature(this.obfSignature, className ->
-                {
+                MethodDescriptor newDescriptor = obfDescriptor.remap(className -> {
                         if (className.equals(oldObfClassName)) {
                                 return newObfClassName;
                         }
-                        return null;
+                        return className;
                 });
 
-                if (!newSignature.equals(this.obfSignature)) {
-                        this.obfSignature = newSignature;
+                if (!newDescriptor.equals(this.obfDescriptor)) {
+                        this.obfDescriptor = newDescriptor;
                         return true;
                 }
                 return false;
         }
 
-        public boolean isConstructor() {
-                return this.obfName.startsWith("<");
-        }
-
         @Override
-        public BehaviorEntry getObfEntry(ClassEntry classEntry) {
-                if (isConstructor()) {
-                        return new ConstructorEntry(classEntry, this.obfSignature);
-                } else {
-                        return new MethodEntry(classEntry, this.obfName, this.obfSignature);
-                }
+        public MethodEntry getObfEntry(ClassEntry classEntry) {
+                return new MethodEntry(classEntry, this.obfName, this.obfDescriptor);
         }
 
         public Mappings.EntryModifier getModifier() {
@@ -210,4 +203,8 @@ public class MethodMapping implements Comparable<MethodMapping>, MemberMapping<B
         public void setModifier(Mappings.EntryModifier modifier) {
                 this.modifier = modifier;
         }
+
+        public boolean isObfuscated() {
+                return deobfName == null || deobfName.equals(obfName);
+        }
 }
diff --git a/src/main/java/cuchaz/enigma/mapping/NameValidator.java b/src/main/java/cuchaz/enigma/mapping/NameValidator.java
index aa3dc4d..9273c9b 100644
--- a/src/main/java/cuchaz/enigma/mapping/NameValidator.java
+++ b/src/main/java/cuchaz/enigma/mapping/NameValidator.java
@@ -11,8 +11,8 @@
 
 package cuchaz.enigma.mapping;
 
+import cuchaz.enigma.mapping.entry.ClassEntry;
 import cuchaz.enigma.throwables.IllegalNameException;
-import javassist.bytecode.Descriptor;
 
 import java.util.Arrays;
 import java.util.List;
@@ -23,11 +23,11 @@ public class NameValidator {
         private static final Pattern IdentifierPattern;
         private static final Pattern ClassPattern;
         private static final List<String> ReservedWords = Arrays.asList(
-                "abstract", "continue", "for", "new", "switch", "assert", "default", "goto", "package", "synchronized",
-                "boolean", "do", "if", "private", "this", "break", "double", "implements", "protected", "throw", "byte",
-                "else", "import", "public", "throws", "case", "enum", "instanceof", "return", "transient", "catch",
-                "extends", "int", "short", "try", "char", "final", "interface", "static", "void", "class", "finally",
-                "long", "strictfp", "volatile", "const", "float", "native", "super", "while"
+                        "abstract", "continue", "for", "new", "switch", "assert", "default", "goto", "package", "synchronized",
+                        "boolean", "do", "if", "private", "this", "break", "double", "implements", "protected", "throw", "byte",
+                        "else", "import", "public", "throws", "case", "enum", "instanceof", "return", "transient", "catch",
+                        "extends", "int", "short", "try", "char", "final", "interface", "static", "void", "class", "finally",
+                        "long", "strictfp", "volatile", "const", "float", "native", "super", "while"
         );
 
         static {
@@ -43,10 +43,10 @@ public class NameValidator {
                 if (!ClassPattern.matcher(name).matches() || ReservedWords.contains(name)) {
                         throw new IllegalNameException(name, "This doesn't look like a legal class name");
                 }
-                if (packageRequired && new ClassEntry(name).getPackageName() == null) {
+                if (packageRequired && ClassEntry.getPackageName(name) == null) {
                         throw new IllegalNameException(name, "Class must be in a package");
                 }
-                return Descriptor.toJvmName(name);
+                return name;
         }
 
         public static String validateFieldName(String name) {
diff --git a/src/main/java/cuchaz/enigma/mapping/ProcyonEntryFactory.java b/src/main/java/cuchaz/enigma/mapping/ProcyonEntryFactory.java
deleted file mode 100644
index 33d930d..0000000
--- a/src/main/java/cuchaz/enigma/mapping/ProcyonEntryFactory.java
+++ /dev/null
@@ -1,67 +0,0 @@
-/*******************************************************************************
- * Copyright (c) 2015 Jeff Martin.
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Lesser General Public
- * License v3.0 which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/lgpl.html
- * <p>
- * Contributors:
- * Jeff Martin - initial API and implementation
- ******************************************************************************/
-
-package cuchaz.enigma.mapping;
-
-import com.strobel.assembler.metadata.*;
-
-import java.util.List;
-
-public class ProcyonEntryFactory {
-
-        private static String getErasedSignature(MemberReference def) {
-                if (!(def instanceof MethodReference))
-                        return def.getErasedSignature();
-                MethodReference methodReference = (MethodReference) def;
-                StringBuilder builder = new StringBuilder("(");
-                for (ParameterDefinition param : methodReference.getParameters()) {
-                        TypeReference paramType = param.getParameterType();
-                        if (paramType.getErasedSignature().equals("Ljava/lang/Object;") && paramType.hasExtendsBound() && paramType.getExtendsBound() instanceof CompoundTypeReference) {
-                                List<TypeReference> interfaces = ((CompoundTypeReference) paramType.getExtendsBound()).getInterfaces();
-                                interfaces.forEach((inter) -> builder.append(inter.getErasedSignature()));
-                        } else
-                                builder.append(paramType.getErasedSignature());
-                }
-                builder.append(")");
-
-                TypeReference returnType = methodReference.getReturnType();
-                if (returnType.getErasedSignature().equals("Ljava/lang/Object;") && returnType.hasExtendsBound() && returnType.getExtendsBound() instanceof CompoundTypeReference) {
-                        List<TypeReference> interfaces = ((CompoundTypeReference) returnType.getExtendsBound()).getInterfaces();
-                        interfaces.forEach((inter) -> builder.append(inter.getErasedSignature()));
-                } else
-                        builder.append(returnType.getErasedSignature());
-                return builder.toString();
-        }
-
-        public static FieldEntry getFieldEntry(MemberReference def) {
-                return new FieldEntry(new ClassEntry(def.getDeclaringType().getInternalName()), def.getName(), new Type(def.getErasedSignature()));
-        }
-
-        public static MethodEntry getMethodEntry(MemberReference def) {
-                return new MethodEntry(new ClassEntry(def.getDeclaringType().getInternalName()), def.getName(), new Signature(getErasedSignature(def)));
-        }
-
-        public static ConstructorEntry getConstructorEntry(MethodReference def) {
-                if (def.isTypeInitializer()) {
-                        return new ConstructorEntry(new ClassEntry(def.getDeclaringType().getInternalName()));
-                } else {
-                        return new ConstructorEntry(new ClassEntry(def.getDeclaringType().getInternalName()), new Signature(def.getErasedSignature()));
-                }
-        }
-
-        public static BehaviorEntry getBehaviorEntry(MethodReference def) {
-                if (def.isConstructor() || def.isTypeInitializer()) {
-                        return getConstructorEntry(def);
-                } else {
-                        return getMethodEntry(def);
-                }
-        }
-}
diff --git a/src/main/java/cuchaz/enigma/mapping/Signature.java b/src/main/java/cuchaz/enigma/mapping/Signature.java
index 78130d6..071e4af 100644
--- a/src/main/java/cuchaz/enigma/mapping/Signature.java
+++ b/src/main/java/cuchaz/enigma/mapping/Signature.java
@@ -1,106 +1,82 @@
-/*******************************************************************************
- * Copyright (c) 2015 Jeff Martin.
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Lesser General Public
- * License v3.0 which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/lgpl.html
- * <p>
- * Contributors:
- * Jeff Martin - initial API and implementation
- ******************************************************************************/
-
 package cuchaz.enigma.mapping;
 
-import com.google.common.collect.Lists;
-import cuchaz.enigma.utils.Utils;
+import cuchaz.enigma.bytecode.translators.TranslationSignatureVisitor;
+import org.objectweb.asm.signature.SignatureReader;
+import org.objectweb.asm.signature.SignatureVisitor;
+import org.objectweb.asm.signature.SignatureWriter;
 
-import java.util.List;
+import java.util.function.Function;
+import java.util.regex.Pattern;
 
 public class Signature {
+        private static final Pattern OBJECT_PATTERN = Pattern.compile(".*:Ljava/lang/Object;:.*");
 
-        private List<Type> argumentTypes;
-        private Type returnType;
+        private final String signature;
+        private final boolean isType;
 
-        public Signature(String signature) {
-                try {
-                        this.argumentTypes = Lists.newArrayList();
-                        int i = 0;
-                        while (i < signature.length()) {
-                                char c = signature.charAt(i);
-                                if (c == '(') {
-                                        assert (this.argumentTypes.isEmpty());
-                                        assert (this.returnType == null);
-                                        i++;
-                                } else if (c == ')') {
-                                        i++;
-                                        break;
-                                } else {
-                                        String type = Type.parseFirst(signature.substring(i));
-                                        this.argumentTypes.add(new Type(type));
-                                        i += type.length();
-                                }
-                        }
-                        this.returnType = new Type(Type.parseFirst(signature.substring(i)));
-                } catch (Exception ex) {
-                        throw new IllegalArgumentException("Unable to parse signature: " + signature, ex);
+        private Signature(String signature, boolean isType) {
+                if (signature != null && OBJECT_PATTERN.matcher(signature).matches()) {
+                        signature = signature.replaceAll(":Ljava/lang/Object;:", "::");
                 }
+
+                this.signature = signature;
+                this.isType = isType;
         }
 
-        public Signature(Signature other, ClassNameReplacer replacer) {
-                this.argumentTypes = Lists.newArrayList(other.argumentTypes);
-                for (int i = 0; i < this.argumentTypes.size(); i++) {
-                        this.argumentTypes.set(i, new Type(this.argumentTypes.get(i), replacer));
+        public static Signature createTypedSignature(String signature) {
+                if (signature != null && !signature.isEmpty()) {
+                        return new Signature(signature, true);
                 }
-                this.returnType = new Type(other.returnType, replacer);
+                return new Signature(null, true);
         }
 
-        public List<Type> getArgumentTypes() {
-                return this.argumentTypes;
+        public static Signature createSignature(String signature) {
+                if (signature != null && !signature.isEmpty()) {
+                        return new Signature(signature, false);
+                }
+                return new Signature(null, false);
         }
 
-        public Type getReturnType() {
-                return this.returnType;
+        public String getSignature() {
+                return signature;
         }
 
-        @Override
-        public String toString() {
-                StringBuilder buf = new StringBuilder();
-                buf.append("(");
-                for (Type type : this.argumentTypes) {
-                        buf.append(type);
-                }
-                buf.append(")");
-                buf.append(this.returnType);
-                return buf.toString();
+        public boolean isType() {
+                return isType;
         }
 
-        public Iterable<Type> types() {
-                List<Type> types = Lists.newArrayList();
-                types.addAll(this.argumentTypes);
-                types.add(this.returnType);
-                return types;
+        public Signature remap(Function<String, String> remapper) {
+                if (signature == null) {
+                        return this;
+                }
+                SignatureWriter writer = new SignatureWriter();
+                SignatureVisitor visitor = new TranslationSignatureVisitor(remapper, writer);
+                if (isType) {
+                        new SignatureReader(signature).acceptType(visitor);
+                } else {
+                        new SignatureReader(signature).accept(visitor);
+                }
+                return new Signature(writer.toString(), isType);
         }
 
         @Override
-        public boolean equals(Object other) {
-                return other instanceof Signature && equals((Signature) other);
-        }
-
-        public boolean equals(Signature other) {
-                return this.argumentTypes.equals(other.argumentTypes) && this.returnType.equals(other.returnType);
+        public boolean equals(Object obj) {
+                if (obj instanceof Signature) {
+                        Signature other = (Signature) obj;
+                        return (other.signature == null && signature == null || other.signature != null
+                                        && signature != null && other.signature.equals(signature))
+                                        && other.isType == this.isType;
+                }
+                return false;
         }
 
         @Override
         public int hashCode() {
-                return Utils.combineHashesOrdered(this.argumentTypes.hashCode(), this.returnType.hashCode());
+                return signature.hashCode() | (isType ? 1 : 0) << 16;
         }
 
-        public boolean hasClass(ClassEntry classEntry) {
-                for (Type type : types()) {
-                        if (type.hasClass() && type.getClassEntry().equals(classEntry)) {
-                                return true;
-                        }
-                }
-                return false;
+        @Override
+        public String toString() {
+                return signature;
         }
 }
diff --git a/src/main/java/cuchaz/enigma/mapping/TranslationDirection.java b/src/main/java/cuchaz/enigma/mapping/TranslationDirection.java
index 17e3187..4bbde54 100644
--- a/src/main/java/cuchaz/enigma/mapping/TranslationDirection.java
+++ b/src/main/java/cuchaz/enigma/mapping/TranslationDirection.java
@@ -13,15 +13,21 @@ package cuchaz.enigma.mapping;
 
 public enum TranslationDirection {
 
-        Deobfuscating {
+        DEOBFUSCATING {
                 @Override
                 public <T> T choose(T deobfChoice, T obfChoice) {
+                        if (deobfChoice == null) {
+                                return obfChoice;
+                        }
                         return deobfChoice;
                 }
         },
-        Obfuscating {
+        OBFUSCATING {
                 @Override
                 public <T> T choose(T deobfChoice, T obfChoice) {
+                        if (obfChoice == null) {
+                                return deobfChoice;
+                        }
                         return obfChoice;
                 }
         };
diff --git a/src/main/java/cuchaz/enigma/mapping/Translator.java b/src/main/java/cuchaz/enigma/mapping/Translator.java
index 8d464fc..a9ff1cb 100644
--- a/src/main/java/cuchaz/enigma/mapping/Translator.java
+++ b/src/main/java/cuchaz/enigma/mapping/Translator.java
@@ -11,332 +11,99 @@
 
 package cuchaz.enigma.mapping;
 
-import com.google.common.collect.Lists;
-import com.google.common.collect.Maps;
-import cuchaz.enigma.analysis.TranslationIndex;
+import cuchaz.enigma.mapping.entry.*;
+import org.objectweb.asm.Handle;
+import org.objectweb.asm.Type;
 
-import java.util.List;
-import java.util.Map;
+public interface Translator {
+        ClassEntry getTranslatedClass(ClassEntry entry);
 
-public class Translator {
+        ClassDefEntry getTranslatedClassDef(ClassDefEntry entry);
 
-        private TranslationDirection direction;
-        private Map<String, ClassMapping> classes;
-        private TranslationIndex index;
+        FieldEntry getTranslatedField(FieldEntry entry);
 
-        private ClassNameReplacer classNameReplacer = className -> translateEntry(new ClassEntry(className)).getName();
+        FieldDefEntry getTranslatedFieldDef(FieldDefEntry entry);
 
-        public Translator() {
-                this.direction = null;
-                this.classes = Maps.newHashMap();
-                this.index = new TranslationIndex();
-        }
+        MethodEntry getTranslatedMethod(MethodEntry entry);
 
-        public Translator(TranslationDirection direction, Map<String, ClassMapping> classes, TranslationIndex index) {
-                this.direction = direction;
-                this.classes = classes;
-                this.index = index;
-        }
+        MethodDefEntry getTranslatedMethodDef(MethodDefEntry entry);
 
-        public TranslationDirection getDirection() {
-                return direction;
-        }
+        LocalVariableEntry getTranslatedVariable(LocalVariableEntry entry);
 
-        public TranslationIndex getTranslationIndex() {
-                return index;
-        }
+        LocalVariableDefEntry getTranslatedVariableDef(LocalVariableDefEntry entry);
 
-        @SuppressWarnings("unchecked")
-        public <T extends Entry> T translateEntry(T entry) {
-                if (entry instanceof ClassEntry) {
-                        return (T) translateEntry((ClassEntry) entry);
-                } else if (entry instanceof FieldEntry) {
-                        return (T) translateEntry((FieldEntry) entry);
-                } else if (entry instanceof MethodEntry) {
-                        return (T) translateEntry((MethodEntry) entry);
-                } else if (entry instanceof ConstructorEntry) {
-                        return (T) translateEntry((ConstructorEntry) entry);
-                } else if (entry instanceof ArgumentEntry) {
-                        return (T) translateEntry((ArgumentEntry) entry);
-                } else if (entry instanceof LocalVariableEntry) {
-                        return (T) translateEntry((LocalVariableEntry) entry);
-                } else {
-                        throw new Error("Unknown entry type: " + entry.getClass().getName());
-                }
-        }
+        boolean hasClassMapping(ClassEntry entry);
 
-        public <T extends Entry> String translate(T entry) {
-                if (entry instanceof ClassEntry) {
-                        return translate((ClassEntry) entry);
-                } else if (entry instanceof FieldEntry) {
-                        return translate((FieldEntry) entry);
-                } else if (entry instanceof MethodEntry) {
-                        return translate((MethodEntry) entry);
-                } else if (entry instanceof ConstructorEntry) {
-                        return translate(entry);
-                } else if (entry instanceof ArgumentEntry) {
-                        return translate((ArgumentEntry) entry);
-                } else if (entry instanceof LocalVariableEntry) {
-                        return translate((LocalVariableEntry) entry);
-                } else {
-                        throw new Error("Unknown entry type: " + entry.getClass().getName());
-                }
-        }
+        boolean hasFieldMapping(FieldEntry entry);
 
-        public String translate(LocalVariableEntry in) {
-                LocalVariableEntry translated = translateEntry(in);
-                if (translated.equals(in)) {
-                        return null;
-                }
-                return translated.getName();
-        }
+        boolean hasMethodMapping(MethodEntry entry);
 
-        public LocalVariableEntry translateEntry(LocalVariableEntry in) {
-                // TODO: Implement it
-                return in;
-        }
+        boolean hasLocalVariableMapping(LocalVariableEntry entry);
 
-        public String translate(ClassEntry in) {
-                ClassEntry translated = translateEntry(in);
-                if (translated.equals(in)) {
-                        return null;
-                }
-                return translated.getName();
-        }
+        TypeDescriptor getTranslatedTypeDesc(TypeDescriptor desc);
 
-        public String translateClass(String className) {
-                return translate(new ClassEntry(className));
-        }
-
-        public ClassEntry translateEntry(ClassEntry in) {
+        MethodDescriptor getTranslatedMethodDesc(MethodDescriptor descriptor);
 
-                if (in.isInnerClass()) {
+        Signature getTranslatedSignature(Signature signature);
 
-                        // translate as much of the class chain as we can
-                        List<ClassMapping> mappingsChain = getClassMappingChain(in);
-                        String[] obfClassNames = in.getName().split("\\$");
-                        StringBuilder buf = new StringBuilder();
-                        for (int i = 0; i < obfClassNames.length; i++) {
-                                boolean isFirstClass = buf.length() == 0;
-                                String className = null;
-                                ClassMapping classMapping = mappingsChain.get(i);
-                                if (classMapping != null) {
-                                        className = this.direction.choose(
-                                                classMapping.getDeobfName(),
-                                                isFirstClass ? classMapping.getObfFullName() : classMapping.getObfSimpleName()
-                                        );
-                                }
-                                if (className == null) {
-                                        className = obfClassNames[i];
-                                }
-                                if (!isFirstClass) {
-                                        buf.append("$");
-                                }
-                                buf.append(className);
+        default Type getTranslatedType(Type type) {
+                String descString = type.getDescriptor();
+                switch (type.getSort()) {
+                        case Type.OBJECT: {
+                                ClassEntry classEntry = new ClassEntry(type.getInternalName());
+                                return Type.getObjectType(getTranslatedClass(classEntry).getName());
                         }
-                        return new ClassEntry(buf.toString());
-
-                } else {
-
-                        // normal classes are easy
-                        ClassMapping classMapping = this.classes.get(in.getName());
-                        if (classMapping == null) {
-                                return in;
+                        case Type.ARRAY: {
+                                TypeDescriptor descriptor = new TypeDescriptor(descString);
+                                return Type.getType(getTranslatedTypeDesc(descriptor).toString());
                         }
-                        return this.direction.choose(
-                                classMapping.getDeobfName() != null ? new ClassEntry(classMapping.getDeobfName()) : in,
-                                new ClassEntry(classMapping.getObfFullName())
-                        );
-                }
-        }
-
-        public String translate(FieldEntry in) {
-
-                // resolve the class entry
-                ClassEntry resolvedClassEntry = this.index.resolveEntryClass(in);
-                if (resolvedClassEntry != null) {
-
-                        // look for the class
-                        ClassMapping classMapping = findClassMapping(resolvedClassEntry);
-                        if (classMapping != null) {
-
-                                // look for the field
-                                String translatedName = this.direction.choose(
-                                        classMapping.getDeobfFieldName(in.getName(), in.getType()),
-                                        classMapping.getObfFieldName(in.getName(), translateType(in.getType()))
-                                );
-                                if (translatedName != null) {
-                                        return translatedName;
-                                }
+                        case Type.METHOD: {
+                                MethodDescriptor descriptor = new MethodDescriptor(descString);
+                                return Type.getMethodType(getTranslatedMethodDesc(descriptor).toString());
                         }
                 }
-                return null;
+                return type;
         }
 
-        public FieldEntry translateEntry(FieldEntry in) {
-                String name = translate(in);
-                if (name == null) {
-                        name = in.getName();
-                }
-                return new FieldEntry(translateEntry(in.getClassEntry()), name, translateType(in.getType()));
+        default Handle getTranslatedHandle(Handle handle) {
+                MethodEntry entry = new MethodEntry(new ClassEntry(handle.getOwner()), handle.getName(), new MethodDescriptor(handle.getDesc()));
+                MethodEntry translatedMethod = getTranslatedMethod(entry);
+                ClassEntry ownerClass = translatedMethod.getOwnerClassEntry();
+                return new Handle(handle.getTag(), ownerClass.getName(), translatedMethod.getName(), translatedMethod.getDesc().toString(), handle.isInterface());
         }
 
-        public String translate(MethodEntry in) {
-                // resolve the class entry
-                ClassEntry resolvedClassEntry = this.index.resolveEntryClass(in, true);
-                if (resolvedClassEntry != null) {
-
-                        // look for class
-                        ClassMapping classMapping = findClassMapping(resolvedClassEntry);
-                        if (classMapping != null) {
-
-                                // look for the method
-                                MethodMapping methodMapping = this.direction.choose(
-                                        classMapping.getMethodByObf(in.getName(), in.getSignature()),
-                                        classMapping.getMethodByDeobf(in.getName(), translateSignature(in.getSignature()))
-                                );
-                                if (methodMapping != null) {
-                                        return this.direction.choose(methodMapping.getDeobfName(), methodMapping.getObfName());
-                                }
-                        }
+        default Object getTranslatedValue(Object value) {
+                if (value instanceof Type) {
+                        return this.getTranslatedType((Type) value);
+                } else if (value instanceof Handle) {
+                        return getTranslatedHandle((Handle) value);
                 }
-                return null;
+                return value;
         }
 
-        public MethodEntry translateEntry(MethodEntry in) {
-                String name = translate(in);
-                if (name == null) {
-                        name = in.getName();
-                }
-                return new MethodEntry(translateEntry(in.getClassEntry()), name, translateSignature(in.getSignature()));
-        }
-
-        public ConstructorEntry translateEntry(ConstructorEntry in) {
-                if (in.isStatic()) {
-                        return new ConstructorEntry(translateEntry(in.getClassEntry()));
-                } else {
-                        return new ConstructorEntry(translateEntry(in.getClassEntry()), translateSignature(in.getSignature()));
-                }
-        }
-
-        public BehaviorEntry translateEntry(BehaviorEntry in) {
-                if (in instanceof MethodEntry) {
-                        return translateEntry((MethodEntry) in);
-                } else if (in instanceof ConstructorEntry) {
-                        return translateEntry((ConstructorEntry) in);
-                }
-                throw new Error("Wrong entry type!");
-        }
-
-        // TODO: support not identical behavior (specific to constructor)
-        public String translate(ArgumentEntry in) {
-                String classTranslate = translateArgument(in);
-
-                // Not found in this class
-                if (classTranslate == null) {
-                        List<ClassEntry> ancestry = this.index.getAncestry(in.getClassEntry());
-
-                        // Check in mother class for the arg
-                        for (ClassEntry entry : ancestry) {
-                                ArgumentEntry motherArg = in.cloneToNewClass(entry);
-                                if (this.index.entryExists(motherArg)) {
-                                        String result = translateArgument(motherArg);
-                                        if (result != null)
-                                                return result;
-                                }
-                        }
-                }
-                return classTranslate;
-        }
-
-        public String translateArgument(ArgumentEntry in) {
-                // look for identical behavior in superclasses
-                ClassEntry entry = in.getClassEntry();
-
-                if (entry != null) {
-                        // look for the class
-                        ClassMapping classMapping = findClassMapping(entry);
-                        if (classMapping != null) {
-
-                                // look for the method
-                                MethodMapping methodMapping = this.direction.choose(
-                                        classMapping.getMethodByObf(in.getMethodName(), in.getMethodSignature()),
-                                        classMapping.getMethodByDeobf(in.getMethodName(), translateSignature(in.getMethodSignature()))
-                                );
-                                if (methodMapping != null) {
-                                        return this.direction.choose(
-                                                methodMapping.getDeobfArgumentName(in.getIndex()),
-                                                methodMapping.getObfArgumentName(in.getIndex())
-                                        );
-                                }
-                        }
-                }
-                return null;
-        }
-
-        public ArgumentEntry translateEntry(ArgumentEntry in) {
-                String name = translate(in);
-                if (name == null) {
-                        name = in.getName();
-                }
-                return new ArgumentEntry(translateEntry(in.getBehaviorEntry()), in.getIndex(), name);
-        }
-
-        public Type translateType(Type type) {
-                return new Type(type, this.classNameReplacer);
-        }
-
-        public Signature translateSignature(Signature signature) {
-                return new Signature(signature, this.classNameReplacer);
-        }
-
-        private ClassMapping findClassMapping(ClassEntry in) {
-                List<ClassMapping> mappingChain = getClassMappingChain(in);
-                return mappingChain.get(mappingChain.size() - 1);
-        }
-
-        private List<ClassMapping> getClassMappingChain(ClassEntry in) {
-
-                // get a list of all the classes in the hierarchy
-                String[] parts = in.getName().split("\\$");
-                List<ClassMapping> mappingsChain = Lists.newArrayList();
-
-                // get mappings for the outer class
-                ClassMapping outerClassMapping = this.classes.get(parts[0]);
-                mappingsChain.add(outerClassMapping);
-
-                for (int i = 1; i < parts.length; i++) {
-
-                        // get mappings for the inner class
-                        ClassMapping innerClassMapping = null;
-                        if (outerClassMapping != null) {
-                                innerClassMapping = this.direction.choose(
-                                        outerClassMapping.getInnerClassByObfSimple(parts[i]),
-                                        outerClassMapping.getInnerClassByDeobfThenObfSimple(parts[i])
-                                );
-                        }
-                        mappingsChain.add(innerClassMapping);
-                        outerClassMapping = innerClassMapping;
-                }
-
-                assert (mappingsChain.size() == parts.length);
-                return mappingsChain;
-        }
-
-        public Mappings.EntryModifier getModifier(Entry entry) {
-                ClassMapping classMapping = findClassMapping(entry.getClassEntry());
-                if (classMapping != null && !entry.getName().equals("<clinit>")) {
-                        if (entry instanceof ClassEntry)
-                                return classMapping.getModifier();
-                        else if (entry instanceof FieldEntry) {
-                                FieldMapping fieldMapping = classMapping.getFieldByObf(entry.getName(), ((FieldEntry) entry).getType());
-                                return fieldMapping != null ? fieldMapping.getModifier() : Mappings.EntryModifier.UNCHANGED;
-                        } else if (entry instanceof BehaviorEntry) {
-                                MethodMapping methodMapping = classMapping.getMethodByObf(entry.getName(), ((BehaviorEntry) entry).getSignature());
-                                return methodMapping != null ? methodMapping.getModifier() : Mappings.EntryModifier.UNCHANGED;
-                        } else
-                                throw new Error("Unknown entry type: " + entry.getClass().getName());
+        @SuppressWarnings("unchecked")
+        default <T extends Entry> T getTranslatedEntry(T entry) {
+                if (entry instanceof ClassDefEntry) {
+                        return (T) getTranslatedClassDef((ClassDefEntry) entry);
+                } else if (entry instanceof ClassEntry) {
+                        return (T) getTranslatedClass((ClassEntry) entry);
+                } else if (entry instanceof FieldDefEntry) {
+                        return (T) getTranslatedFieldDef((FieldDefEntry) entry);
+                } else if (entry instanceof MethodDefEntry) {
+                        return (T) getTranslatedMethodDef((MethodDefEntry) entry);
+                } else if (entry instanceof FieldEntry) {
+                        return (T) getTranslatedField((FieldEntry) entry);
+                } else if (entry instanceof MethodEntry) {
+                        return (T) getTranslatedMethod((MethodEntry) entry);
+                } else if (entry instanceof LocalVariableDefEntry) {
+                        return (T) getTranslatedVariableDef((LocalVariableDefEntry) entry);
+                } else if (entry instanceof LocalVariableEntry) {
+                        return (T) getTranslatedVariable((LocalVariableEntry) entry);
+                } else if (entry instanceof TypeDescriptor) {
+                        return (T) getTranslatedTypeDesc((TypeDescriptor) entry);
+                } else if (entry instanceof MethodDescriptor) {
+                        return (T) getTranslatedMethodDesc((MethodDescriptor) entry);
                 }
-                return Mappings.EntryModifier.UNCHANGED;
+                throw new IllegalArgumentException("Cannot translate unknown entry type");
         }
 }
diff --git a/src/main/java/cuchaz/enigma/mapping/Type.java b/src/main/java/cuchaz/enigma/mapping/TypeDescriptor.java
index 609bd64..b7b1255 100644
--- a/src/main/java/cuchaz/enigma/mapping/Type.java
+++ b/src/main/java/cuchaz/enigma/mapping/TypeDescriptor.java
@@ -11,47 +11,36 @@
 
 package cuchaz.enigma.mapping;
 
+import com.google.common.base.Preconditions;
 import com.google.common.collect.Maps;
+import cuchaz.enigma.mapping.entry.ClassEntry;
 
 import java.util.Map;
+import java.util.function.Function;
 
-public class Type {
+public class TypeDescriptor {
 
-        protected String name;
+        protected final String desc;
 
-        public Type(String name) {
+        public TypeDescriptor(String desc) {
+                Preconditions.checkNotNull(desc, "Desc cannot be null");
 
                 // don't deal with generics
                 // this is just for raw jvm types
-                if (name.charAt(0) == 'T' || name.indexOf('<') >= 0 || name.indexOf('>') >= 0) {
-                        throw new IllegalArgumentException("don't use with generic types or templates: " + name);
+                if (desc.charAt(0) == 'T' || desc.indexOf('<') >= 0 || desc.indexOf('>') >= 0) {
+                        throw new IllegalArgumentException("don't use with generic types or templates: " + desc);
                 }
 
-                this.name = name;
-        }
-
-        public Type(Type other, ClassNameReplacer replacer) {
-                this.name = other.name;
-                if (other.isClass()) {
-                        String replacedName = replacer.replace(other.getClassEntry().getClassName());
-                        if (replacedName != null) {
-                                this.name = "L" + replacedName + ";";
-                        }
-                } else if (other.isArray() && other.hasClass()) {
-                        String replacedName = replacer.replace(other.getClassEntry().getClassName());
-                        if (replacedName != null) {
-                                this.name = Type.getArrayPrefix(other.getArrayDimension()) + "L" + replacedName + ";";
-                        }
-                }
+                this.desc = desc;
         }
 
         public static String parseFirst(String in) {
 
                 if (in == null || in.length() <= 0) {
-                        throw new IllegalArgumentException("No type to parse, input is empty!");
+                        throw new IllegalArgumentException("No desc to parse, input is empty!");
                 }
 
-                // read one type from the input
+                // read one desc from the input
 
                 char c = in.charAt(0);
 
@@ -79,21 +68,13 @@ public class Type {
                 // then check for arrays
                 int dim = countArrayDimension(in);
                 if (dim > 0) {
-                        String arrayType = Type.parseFirst(in.substring(dim));
+                        String arrayType = TypeDescriptor.parseFirst(in.substring(dim));
                         return in.substring(0, dim + arrayType.length());
                 }
 
                 throw new IllegalArgumentException("don't know how to parse: " + in);
         }
 
-        private static String getArrayPrefix(int dimension) {
-                StringBuilder buf = new StringBuilder();
-                for (int i = 0; i < dimension; i++) {
-                        buf.append("[");
-                }
-                return buf.toString();
-        }
-
         private static int countArrayDimension(String in) {
                 int i = 0;
                 while (i < in.length() && in.charAt(i) == '[')
@@ -121,33 +102,37 @@ public class Type {
                 return null;
         }
 
+        public static TypeDescriptor of(String name) {
+                return new TypeDescriptor("L" + name + ";");
+        }
+
         @Override
         public String toString() {
-                return this.name;
+                return this.desc;
         }
 
         public boolean isVoid() {
-                return this.name.length() == 1 && this.name.charAt(0) == 'V';
+                return this.desc.length() == 1 && this.desc.charAt(0) == 'V';
         }
 
         public boolean isPrimitive() {
-                return this.name.length() == 1 && Primitive.get(this.name.charAt(0)) != null;
+                return this.desc.length() == 1 && Primitive.get(this.desc.charAt(0)) != null;
         }
 
         public Primitive getPrimitive() {
                 if (!isPrimitive()) {
                         throw new IllegalStateException("not a primitive");
                 }
-                return Primitive.get(this.name.charAt(0));
+                return Primitive.get(this.desc.charAt(0));
         }
 
-        public boolean isClass() {
-                return this.name.charAt(0) == 'L' && this.name.charAt(this.name.length() - 1) == ';';
+        public boolean isType() {
+                return this.desc.charAt(0) == 'L' && this.desc.charAt(this.desc.length() - 1) == ';';
         }
 
-        public ClassEntry getClassEntry() {
-                if (isClass()) {
-                        String name = this.name.substring(1, this.name.length() - 1);
+        public ClassEntry getTypeEntry() {
+                if (isType()) {
+                        String name = this.desc.substring(1, this.desc.length() - 1);
 
                         int pos = name.indexOf('<');
                         if (pos >= 0) {
@@ -157,46 +142,70 @@ public class Type {
 
                         return new ClassEntry(name);
 
-                } else if (isArray() && getArrayType().isClass()) {
-                        return getArrayType().getClassEntry();
+                } else if (isArray() && getArrayType().isType()) {
+                        return getArrayType().getTypeEntry();
                 } else {
-                        throw new IllegalStateException("type doesn't have a class");
+                        throw new IllegalStateException("desc doesn't have a class");
                 }
         }
 
         public boolean isArray() {
-                return this.name.charAt(0) == '[';
+                return this.desc.charAt(0) == '[';
         }
 
         public int getArrayDimension() {
                 if (!isArray()) {
                         throw new IllegalStateException("not an array");
                 }
-                return countArrayDimension(this.name);
+                return countArrayDimension(this.desc);
         }
 
-        public Type getArrayType() {
+        public TypeDescriptor getArrayType() {
                 if (!isArray()) {
                         throw new IllegalStateException("not an array");
                 }
-                return new Type(this.name.substring(getArrayDimension(), this.name.length()));
+                return new TypeDescriptor(this.desc.substring(getArrayDimension(), this.desc.length()));
         }
 
-        public boolean hasClass() {
-                return isClass() || (isArray() && getArrayType().hasClass());
+        public boolean containsType() {
+                return isType() || (isArray() && getArrayType().containsType());
         }
 
         @Override
         public boolean equals(Object other) {
-                return other instanceof Type && equals((Type) other);
+                return other instanceof TypeDescriptor && equals((TypeDescriptor) other);
         }
 
-        public boolean equals(Type other) {
-                return this.name.equals(other.name);
+        public boolean equals(TypeDescriptor other) {
+                return this.desc.equals(other.desc);
         }
 
+        @Override
         public int hashCode() {
-                return this.name.hashCode();
+                return this.desc.hashCode();
+        }
+
+        public TypeDescriptor remap(Function<String, String> remapper) {
+                String desc = this.desc;
+                if (isType() || (isArray() && containsType())) {
+                        String replacedName = remapper.apply(this.getTypeEntry().getName());
+                        if (replacedName != null) {
+                                if (this.isType()) {
+                                        desc = "L" + replacedName + ";";
+                                } else {
+                                        desc = getArrayPrefix(this.getArrayDimension()) + "L" + replacedName + ";";
+                                }
+                        }
+                }
+                return new TypeDescriptor(desc);
+        }
+
+        private static String getArrayPrefix(int dimension) {
+                StringBuilder buf = new StringBuilder();
+                for (int i = 0; i < dimension; i++) {
+                        buf.append("[");
+                }
+                return buf.toString();
         }
 
         public enum Primitive {
diff --git a/src/main/java/cuchaz/enigma/mapping/entry/ClassDefEntry.java b/src/main/java/cuchaz/enigma/mapping/entry/ClassDefEntry.java
new file mode 100644
index 0000000..ac1fe2a
--- /dev/null
+++ b/src/main/java/cuchaz/enigma/mapping/entry/ClassDefEntry.java
@@ -0,0 +1,37 @@
+/*******************************************************************************
+ * Copyright (c) 2015 Jeff Martin.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Lesser General Public
+ * License v3.0 which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/lgpl.html
+ * <p>
+ * Contributors:
+ * Jeff Martin - initial API and implementation
+ ******************************************************************************/
+
+package cuchaz.enigma.mapping.entry;
+
+import com.google.common.base.Preconditions;
+import cuchaz.enigma.bytecode.AccessFlags;
+import cuchaz.enigma.mapping.Signature;
+
+public class ClassDefEntry extends ClassEntry {
+        private final AccessFlags access;
+        private final Signature signature;
+
+        public ClassDefEntry(String className, Signature signature, AccessFlags access) {
+                super(className);
+                Preconditions.checkNotNull(signature, "Class signature cannot be null");
+                Preconditions.checkNotNull(access, "Class access cannot be null");
+                this.signature = signature;
+                this.access = access;
+        }
+
+        public Signature getSignature() {
+                return signature;
+        }
+
+        public AccessFlags getAccess() {
+                return access;
+        }
+}
diff --git a/src/main/java/cuchaz/enigma/mapping/ClassEntry.java b/src/main/java/cuchaz/enigma/mapping/entry/ClassEntry.java
index 788811f..c795825 100644
--- a/src/main/java/cuchaz/enigma/mapping/ClassEntry.java
+++ b/src/main/java/cuchaz/enigma/mapping/entry/ClassEntry.java
@@ -9,20 +9,20 @@
  * Jeff Martin - initial API and implementation
  ******************************************************************************/
 
-package cuchaz.enigma.mapping;
+package cuchaz.enigma.mapping.entry;
 
+import com.google.common.base.Preconditions;
 import com.google.common.collect.Lists;
 
 import java.util.List;
 
 public class ClassEntry implements Entry {
 
-        private String name;
+        private final String name;
 
         public ClassEntry(String className) {
-                if (className == null) {
-                        throw new IllegalArgumentException("Class name cannot be null!");
-                }
+                Preconditions.checkNotNull(className, "Class name cannot be null");
+
                 if (className.indexOf('.') >= 0) {
                         throw new IllegalArgumentException("Class name must be in JVM format. ie, path/to/package/class$inner : " + className);
                 }
@@ -49,12 +49,12 @@ public class ClassEntry implements Entry {
         }
 
         @Override
-        public ClassEntry getClassEntry() {
+        public ClassEntry getOwnerClassEntry() {
                 return this;
         }
 
         @Override
-        public ClassEntry cloneToNewClass(ClassEntry classEntry) {
+        public ClassEntry updateOwnership(ClassEntry classEntry) {
                 return classEntry;
         }
 
@@ -77,6 +77,10 @@ public class ClassEntry implements Entry {
                 return this.name;
         }
 
+        public boolean isArray() {
+                return this.name.lastIndexOf('[') >= 0;
+        }
+
         public boolean isInnerClass() {
                 return this.name.lastIndexOf('$') >= 0;
         }
@@ -132,11 +136,7 @@ public class ClassEntry implements Entry {
         }
 
         public String getPackageName() {
-                int pos = this.name.lastIndexOf('/');
-                if (pos > 0) {
-                        return this.name.substring(0, pos);
-                }
-                return null;
+                return getPackageName(this.name);
         }
 
         public String getSimpleName() {
@@ -147,6 +147,14 @@ public class ClassEntry implements Entry {
                 return this.name;
         }
 
+        public static String getPackageName(String name) {
+                int pos = name.lastIndexOf('/');
+                if (pos > 0) {
+                        return name.substring(0, pos);
+                }
+                return null;
+        }
+
         public ClassEntry buildClassEntry(List<ClassEntry> classChain) {
                 assert (classChain.contains(this));
                 StringBuilder buf = new StringBuilder();
diff --git a/src/main/java/cuchaz/enigma/mapping/Entry.java b/src/main/java/cuchaz/enigma/mapping/entry/Entry.java
index c79510b..b612140 100644
--- a/src/main/java/cuchaz/enigma/mapping/Entry.java
+++ b/src/main/java/cuchaz/enigma/mapping/entry/Entry.java
@@ -9,14 +9,14 @@
  * Jeff Martin - initial API and implementation
  ******************************************************************************/
 
-package cuchaz.enigma.mapping;
+package cuchaz.enigma.mapping.entry;
 
 public interface Entry {
         String getName();
 
         String getClassName();
 
-        ClassEntry getClassEntry();
+        ClassEntry getOwnerClassEntry();
 
-        Entry cloneToNewClass(ClassEntry classEntry);
+        Entry updateOwnership(ClassEntry classEntry);
 }
diff --git a/src/main/java/cuchaz/enigma/mapping/entry/EntryFactory.java b/src/main/java/cuchaz/enigma/mapping/entry/EntryFactory.java
new file mode 100644
index 0000000..5bd159f
--- /dev/null
+++ b/src/main/java/cuchaz/enigma/mapping/entry/EntryFactory.java
@@ -0,0 +1,49 @@
+/*******************************************************************************
+ * Copyright (c) 2015 Jeff Martin.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Lesser General Public
+ * License v3.0 which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/lgpl.html
+ * <p>
+ * Contributors:
+ * Jeff Martin - initial API and implementation
+ ******************************************************************************/
+
+package cuchaz.enigma.mapping.entry;
+
+import cuchaz.enigma.analysis.JarIndex;
+import cuchaz.enigma.mapping.ClassMapping;
+import cuchaz.enigma.mapping.FieldMapping;
+import cuchaz.enigma.mapping.MethodDescriptor;
+import cuchaz.enigma.mapping.MethodMapping;
+
+public class EntryFactory {
+        public static ClassEntry getObfClassEntry(JarIndex jarIndex, ClassMapping classMapping) {
+                ClassEntry obfClassEntry = new ClassEntry(classMapping.getObfFullName());
+                return obfClassEntry.buildClassEntry(jarIndex.getObfClassChain(obfClassEntry));
+        }
+
+        private static ClassEntry getObfClassEntry(ClassMapping classMapping) {
+                return new ClassEntry(classMapping.getObfFullName());
+        }
+
+        public static ClassEntry getDeobfClassEntry(ClassMapping classMapping) {
+                return new ClassEntry(classMapping.getDeobfName());
+        }
+
+        public static FieldEntry getObfFieldEntry(ClassMapping classMapping, FieldMapping fieldMapping) {
+                return new FieldEntry(getObfClassEntry(classMapping), fieldMapping.getObfName(), fieldMapping.getObfDesc());
+        }
+
+        public static MethodEntry getMethodEntry(ClassEntry classEntry, String name, MethodDescriptor desc) {
+                return new MethodEntry(classEntry, name, desc);
+        }
+
+        public static MethodEntry getObfMethodEntry(ClassEntry classEntry, MethodMapping methodMapping) {
+                return getMethodEntry(classEntry, methodMapping.getObfName(), methodMapping.getObfDesc());
+        }
+
+        public static MethodEntry getObfMethodEntry(ClassMapping classMapping, MethodMapping methodMapping) {
+                return getObfMethodEntry(getObfClassEntry(classMapping), methodMapping);
+        }
+}
diff --git a/src/main/java/cuchaz/enigma/mapping/entry/FieldDefEntry.java b/src/main/java/cuchaz/enigma/mapping/entry/FieldDefEntry.java
new file mode 100644
index 0000000..d18115b
--- /dev/null
+++ b/src/main/java/cuchaz/enigma/mapping/entry/FieldDefEntry.java
@@ -0,0 +1,43 @@
+/*******************************************************************************
+ * Copyright (c) 2015 Jeff Martin.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Lesser General Public
+ * License v3.0 which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/lgpl.html
+ * <p>
+ * Contributors:
+ * Jeff Martin - initial API and implementation
+ ******************************************************************************/
+
+package cuchaz.enigma.mapping.entry;
+
+import com.google.common.base.Preconditions;
+import cuchaz.enigma.bytecode.AccessFlags;
+import cuchaz.enigma.mapping.Signature;
+import cuchaz.enigma.mapping.TypeDescriptor;
+
+public class FieldDefEntry extends FieldEntry {
+        private final AccessFlags access;
+        private final Signature signature;
+
+        public FieldDefEntry(ClassEntry ownerEntry, String name, TypeDescriptor desc, Signature signature, AccessFlags access) {
+                super(ownerEntry, name, desc);
+                Preconditions.checkNotNull(access, "Field access cannot be null");
+                Preconditions.checkNotNull(signature, "Field signature cannot be null");
+                this.access = access;
+                this.signature = signature;
+        }
+
+        public AccessFlags getAccess() {
+                return access;
+        }
+
+        public Signature getSignature() {
+                return signature;
+        }
+
+        @Override
+        public FieldDefEntry updateOwnership(ClassEntry owner) {
+                return new FieldDefEntry(owner, this.name, this.desc, signature, access);
+        }
+}
diff --git a/src/main/java/cuchaz/enigma/mapping/entry/FieldEntry.java b/src/main/java/cuchaz/enigma/mapping/entry/FieldEntry.java
new file mode 100644
index 0000000..b6e1554
--- /dev/null
+++ b/src/main/java/cuchaz/enigma/mapping/entry/FieldEntry.java
@@ -0,0 +1,77 @@
+/*******************************************************************************
+ * Copyright (c) 2015 Jeff Martin.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Lesser General Public
+ * License v3.0 which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/lgpl.html
+ * <p>
+ * Contributors:
+ * Jeff Martin - initial API and implementation
+ ******************************************************************************/
+
+package cuchaz.enigma.mapping.entry;
+
+import com.google.common.base.Preconditions;
+import cuchaz.enigma.mapping.TypeDescriptor;
+import cuchaz.enigma.utils.Utils;
+
+public class FieldEntry implements Entry {
+
+        protected final ClassEntry ownerEntry;
+        protected final String name;
+        protected final TypeDescriptor desc;
+
+        // NOTE: this argument order is important for the MethodReader/MethodWriter
+        public FieldEntry(ClassEntry ownerEntry, String name, TypeDescriptor desc) {
+                Preconditions.checkNotNull(ownerEntry, "Owner cannot be null");
+                Preconditions.checkNotNull(name, "Field name cannot be null");
+                Preconditions.checkNotNull(desc, "Field descriptor cannot be null");
+
+                this.ownerEntry = ownerEntry;
+                this.name = name;
+                this.desc = desc;
+        }
+
+        @Override
+        public ClassEntry getOwnerClassEntry() {
+                return this.ownerEntry;
+        }
+
+        @Override
+        public String getName() {
+                return this.name;
+        }
+
+        @Override
+        public String getClassName() {
+                return this.ownerEntry.getName();
+        }
+
+        public TypeDescriptor getDesc() {
+                return this.desc;
+        }
+
+        @Override
+        public FieldEntry updateOwnership(ClassEntry owner) {
+                return new FieldEntry(owner, this.name, this.desc);
+        }
+
+        @Override
+        public int hashCode() {
+                return Utils.combineHashesOrdered(this.ownerEntry, this.name, this.desc);
+        }
+
+        @Override
+        public boolean equals(Object other) {
+                return other instanceof FieldEntry && equals((FieldEntry) other);
+        }
+
+        public boolean equals(FieldEntry other) {
+                return this.ownerEntry.equals(other.ownerEntry) && this.name.equals(other.name) && this.desc.equals(other.desc);
+        }
+
+        @Override
+        public String toString() {
+                return this.ownerEntry.getName() + "." + this.name + ":" + this.desc;
+        }
+}
diff --git a/src/main/java/cuchaz/enigma/mapping/entry/LocalVariableDefEntry.java b/src/main/java/cuchaz/enigma/mapping/entry/LocalVariableDefEntry.java
new file mode 100644
index 0000000..7742272
--- /dev/null
+++ b/src/main/java/cuchaz/enigma/mapping/entry/LocalVariableDefEntry.java
@@ -0,0 +1,57 @@
+package cuchaz.enigma.mapping.entry;
+
+import com.google.common.base.Preconditions;
+import cuchaz.enigma.mapping.TypeDescriptor;
+import cuchaz.enigma.utils.Utils;
+
+/**
+ * TypeDescriptor...
+ * Created by Thog
+ * 19/10/2016
+ */
+public class LocalVariableDefEntry extends LocalVariableEntry {
+
+        protected final MethodDefEntry ownerEntry;
+        protected final TypeDescriptor desc;
+
+        public LocalVariableDefEntry(MethodDefEntry ownerEntry, int index, String name, TypeDescriptor desc) {
+                super(ownerEntry, index, name);
+                Preconditions.checkNotNull(desc, "Variable desc cannot be null");
+
+                this.ownerEntry = ownerEntry;
+                this.desc = desc;
+        }
+
+        @Override
+        public MethodDefEntry getOwnerEntry() {
+                return this.ownerEntry;
+        }
+
+        public TypeDescriptor getDesc() {
+                return desc;
+        }
+
+        @Override
+        public LocalVariableDefEntry updateOwnership(ClassEntry classEntry) {
+                return new LocalVariableDefEntry(ownerEntry.updateOwnership(classEntry), index, name, desc);
+        }
+
+        @Override
+        public int hashCode() {
+                return Utils.combineHashesOrdered(this.ownerEntry, this.desc.hashCode(), this.name.hashCode(), Integer.hashCode(this.index));
+        }
+
+        @Override
+        public boolean equals(Object other) {
+                return other instanceof LocalVariableDefEntry && equals((LocalVariableDefEntry) other);
+        }
+
+        public boolean equals(LocalVariableDefEntry other) {
+                return this.ownerEntry.equals(other.ownerEntry) && this.desc.equals(other.desc) && this.name.equals(other.name) && this.index == other.index;
+        }
+
+        @Override
+        public String toString() {
+                return this.ownerEntry + "(" + this.index + ":" + this.name + ":" + this.desc + ")";
+        }
+}
diff --git a/src/main/java/cuchaz/enigma/mapping/entry/LocalVariableEntry.java b/src/main/java/cuchaz/enigma/mapping/entry/LocalVariableEntry.java
new file mode 100644
index 0000000..a794d0a
--- /dev/null
+++ b/src/main/java/cuchaz/enigma/mapping/entry/LocalVariableEntry.java
@@ -0,0 +1,82 @@
+package cuchaz.enigma.mapping.entry;
+
+import com.google.common.base.Preconditions;
+import cuchaz.enigma.mapping.MethodDescriptor;
+import cuchaz.enigma.utils.Utils;
+
+/**
+ * TypeDescriptor...
+ * Created by Thog
+ * 19/10/2016
+ */
+public class LocalVariableEntry implements Entry {
+
+        protected final MethodEntry ownerEntry;
+        protected final String name;
+        protected final int index;
+
+        public LocalVariableEntry(MethodEntry ownerEntry, int index, String name) {
+                Preconditions.checkNotNull(ownerEntry, "Variable owner cannot be null");
+                Preconditions.checkNotNull(name, "Variable name cannot be null");
+                Preconditions.checkArgument(index >= 0, "Index must be positive");
+
+                this.ownerEntry = ownerEntry;
+                this.name = name;
+                this.index = index;
+        }
+
+        public MethodEntry getOwnerEntry() {
+                return this.ownerEntry;
+        }
+
+        public int getIndex() {
+                return index;
+        }
+
+        @Override
+        public String getName() {
+                return this.name;
+        }
+
+        @Override
+        public ClassEntry getOwnerClassEntry() {
+                return this.ownerEntry.getOwnerClassEntry();
+        }
+
+        @Override
+        public String getClassName() {
+                return this.ownerEntry.getClassName();
+        }
+
+        @Override
+        public LocalVariableEntry updateOwnership(ClassEntry classEntry) {
+                return new LocalVariableEntry(ownerEntry.updateOwnership(classEntry), index, name);
+        }
+
+        public String getMethodName() {
+                return this.ownerEntry.getName();
+        }
+
+        public MethodDescriptor getMethodDesc() {
+                return this.ownerEntry.getDesc();
+        }
+
+        @Override
+        public int hashCode() {
+                return Utils.combineHashesOrdered(this.ownerEntry, this.name.hashCode(), Integer.hashCode(this.index));
+        }
+
+        @Override
+        public boolean equals(Object other) {
+                return other instanceof LocalVariableEntry && equals((LocalVariableEntry) other);
+        }
+
+        public boolean equals(LocalVariableEntry other) {
+                return this.ownerEntry.equals(other.ownerEntry) && this.name.equals(other.name) && this.index == other.index;
+        }
+
+        @Override
+        public String toString() {
+                return this.ownerEntry + "(" + this.index + ":" + this.name + ")";
+        }
+}
diff --git a/src/main/java/cuchaz/enigma/mapping/entry/MethodDefEntry.java b/src/main/java/cuchaz/enigma/mapping/entry/MethodDefEntry.java
new file mode 100644
index 0000000..bb7c85e
--- /dev/null
+++ b/src/main/java/cuchaz/enigma/mapping/entry/MethodDefEntry.java
@@ -0,0 +1,54 @@
+/*******************************************************************************
+ * Copyright (c) 2015 Jeff Martin.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Lesser General Public
+ * License v3.0 which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/lgpl.html
+ * <p>
+ * Contributors:
+ * Jeff Martin - initial API and implementation
+ ******************************************************************************/
+
+package cuchaz.enigma.mapping.entry;
+
+import com.google.common.base.Preconditions;
+import cuchaz.enigma.bytecode.AccessFlags;
+import cuchaz.enigma.mapping.MethodDescriptor;
+import cuchaz.enigma.mapping.Signature;
+
+public class MethodDefEntry extends MethodEntry {
+
+        private final AccessFlags access;
+        private final Signature signature;
+
+        public MethodDefEntry(ClassEntry classEntry, String name, MethodDescriptor descriptor, Signature signature, AccessFlags access) {
+                super(classEntry, name, descriptor);
+                Preconditions.checkNotNull(access, "Method access cannot be null");
+                Preconditions.checkNotNull(signature, "Method signature cannot be null");
+                this.access = access;
+                this.signature = signature;
+        }
+
+        public AccessFlags getAccess() {
+                return access;
+        }
+
+        public Signature getSignature() {
+                return signature;
+        }
+
+        public int getVariableOffset(ClassDefEntry ownerEntry) {
+                // Enum constructors have an implicit "name" and "ordinal" parameter as well as "this"
+                if (ownerEntry.getAccess().isEnum() && getName().startsWith("<")) {
+                        return 3;
+                } else {
+                        // If we're not static, "this" is bound to index 0
+                        return getAccess().isStatic() ? 0 : 1;
+                }
+        }
+
+        @Override
+        public MethodDefEntry updateOwnership(ClassEntry classEntry) {
+                return new MethodDefEntry(new ClassEntry(classEntry.getName()), name, descriptor, signature, access);
+        }
+}
diff --git a/src/main/java/cuchaz/enigma/mapping/entry/MethodEntry.java b/src/main/java/cuchaz/enigma/mapping/entry/MethodEntry.java
new file mode 100644
index 0000000..1abc5b1
--- /dev/null
+++ b/src/main/java/cuchaz/enigma/mapping/entry/MethodEntry.java
@@ -0,0 +1,80 @@
+/*******************************************************************************
+ * Copyright (c) 2015 Jeff Martin.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Lesser General Public
+ * License v3.0 which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/lgpl.html
+ * <p>
+ * Contributors:
+ * Jeff Martin - initial API and implementation
+ ******************************************************************************/
+
+package cuchaz.enigma.mapping.entry;
+
+import com.google.common.base.Preconditions;
+import cuchaz.enigma.mapping.MethodDescriptor;
+import cuchaz.enigma.utils.Utils;
+
+public class MethodEntry implements Entry {
+
+        protected final ClassEntry classEntry;
+        protected final String name;
+        protected final MethodDescriptor descriptor;
+
+        public MethodEntry(ClassEntry classEntry, String name, MethodDescriptor descriptor) {
+                Preconditions.checkNotNull(classEntry, "Class cannot be null");
+                Preconditions.checkNotNull(name, "Method name cannot be null");
+                Preconditions.checkNotNull(descriptor, "Method descriptor cannot be null");
+
+                this.classEntry = classEntry;
+                this.name = name;
+                this.descriptor = descriptor;
+        }
+
+        @Override
+        public ClassEntry getOwnerClassEntry() {
+                return this.classEntry;
+        }
+
+        @Override
+        public String getName() {
+                return this.name;
+        }
+
+        public MethodDescriptor getDesc() {
+                return this.descriptor;
+        }
+
+        public boolean isConstructor() {
+                return name.equals("<init>") || name.equals("<clinit>");
+        }
+
+        @Override
+        public String getClassName() {
+                return this.classEntry.getName();
+        }
+
+        @Override
+        public MethodEntry updateOwnership(ClassEntry classEntry) {
+                return new MethodEntry(new ClassEntry(classEntry.getName()), name, descriptor);
+        }
+
+        @Override
+        public int hashCode() {
+                return Utils.combineHashesOrdered(this.classEntry, this.name, this.descriptor);
+        }
+
+        @Override
+        public boolean equals(Object other) {
+                return other instanceof MethodEntry && equals((MethodEntry) other);
+        }
+
+        public boolean equals(MethodEntry other) {
+                return this.classEntry.equals(other.getOwnerClassEntry()) && this.name.equals(other.getName()) && this.descriptor.equals(other.getDesc());
+        }
+
+        @Override
+        public String toString() {
+                return this.classEntry.getName() + "." + this.name + this.descriptor;
+        }
+}
diff --git a/src/main/java/cuchaz/enigma/mapping/entry/ProcyonEntryFactory.java b/src/main/java/cuchaz/enigma/mapping/entry/ProcyonEntryFactory.java
new file mode 100644
index 0000000..73770c5
--- /dev/null
+++ b/src/main/java/cuchaz/enigma/mapping/entry/ProcyonEntryFactory.java
@@ -0,0 +1,48 @@
+/*******************************************************************************
+ * Copyright (c) 2015 Jeff Martin.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Lesser General Public
+ * License v3.0 which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/lgpl.html
+ * <p>
+ * Contributors:
+ * Jeff Martin - initial API and implementation
+ ******************************************************************************/
+
+package cuchaz.enigma.mapping.entry;
+
+import com.strobel.assembler.metadata.FieldDefinition;
+import com.strobel.assembler.metadata.MemberReference;
+import com.strobel.assembler.metadata.MethodDefinition;
+import cuchaz.enigma.bytecode.AccessFlags;
+import cuchaz.enigma.mapping.MethodDescriptor;
+import cuchaz.enigma.mapping.Signature;
+import cuchaz.enigma.mapping.TypeDescriptor;
+
+public class ProcyonEntryFactory {
+        private final ReferencedEntryPool entryPool;
+
+        public ProcyonEntryFactory(ReferencedEntryPool entryPool) {
+                this.entryPool = entryPool;
+        }
+
+        public FieldEntry getFieldEntry(MemberReference def) {
+                ClassEntry classEntry = entryPool.getClass(def.getDeclaringType().getInternalName());
+                return entryPool.getField(classEntry, def.getName(), def.getErasedSignature());
+        }
+
+        public FieldDefEntry getFieldDefEntry(FieldDefinition def) {
+                ClassEntry classEntry = entryPool.getClass(def.getDeclaringType().getInternalName());
+                return new FieldDefEntry(classEntry, def.getName(), new TypeDescriptor(def.getErasedSignature()), Signature.createTypedSignature(def.getSignature()), new AccessFlags(def.getModifiers()));
+        }
+
+        public MethodEntry getMethodEntry(MemberReference def) {
+                ClassEntry classEntry = entryPool.getClass(def.getDeclaringType().getInternalName());
+                return entryPool.getMethod(classEntry, def.getName(), def.getErasedSignature());
+        }
+
+        public MethodDefEntry getMethodDefEntry(MethodDefinition def) {
+                ClassEntry classEntry = entryPool.getClass(def.getDeclaringType().getInternalName());
+                return new MethodDefEntry(classEntry, def.getName(), new MethodDescriptor(def.getErasedSignature()), Signature.createSignature(def.getSignature()), new AccessFlags(def.getModifiers()));
+        }
+}
diff --git a/src/main/java/cuchaz/enigma/mapping/entry/ReferencedEntryPool.java b/src/main/java/cuchaz/enigma/mapping/entry/ReferencedEntryPool.java
new file mode 100644
index 0000000..338d209
--- /dev/null
+++ b/src/main/java/cuchaz/enigma/mapping/entry/ReferencedEntryPool.java
@@ -0,0 +1,53 @@
+/*******************************************************************************
+ * Copyright (c) 2015 Jeff Martin.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Lesser General Public
+ * License v3.0 which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/lgpl.html
+ * <p>
+ * Contributors:
+ * Jeff Martin - initial API and implementation
+ ******************************************************************************/
+
+package cuchaz.enigma.mapping.entry;
+
+import cuchaz.enigma.mapping.MethodDescriptor;
+import cuchaz.enigma.mapping.TypeDescriptor;
+
+import java.util.HashMap;
+import java.util.Map;
+
+public class ReferencedEntryPool {
+        private final Map<String, ClassEntry> classEntries = new HashMap<>();
+        private final Map<String, Map<String, MethodEntry>> methodEntries = new HashMap<>();
+        private final Map<String, Map<String, FieldEntry>> fieldEntries = new HashMap<>();
+
+        public ClassEntry getClass(String name) {
+                return this.classEntries.computeIfAbsent(name, s -> new ClassEntry(name));
+        }
+
+        public MethodEntry getMethod(ClassEntry ownerEntry, String name, String desc) {
+                return getMethod(ownerEntry, name, new MethodDescriptor(desc));
+        }
+
+        public MethodEntry getMethod(ClassEntry ownerEntry, String name, MethodDescriptor desc) {
+                String key = name + desc.toString();
+                return getClassMethods(ownerEntry.getName()).computeIfAbsent(key, s -> new MethodEntry(ownerEntry, name, desc));
+        }
+
+        public FieldEntry getField(ClassEntry ownerEntry, String name, String desc) {
+                return getField(ownerEntry, name, new TypeDescriptor(desc));
+        }
+
+        public FieldEntry getField(ClassEntry ownerEntry, String name, TypeDescriptor desc) {
+                return getClassFields(ownerEntry.getName()).computeIfAbsent(name, s -> new FieldEntry(ownerEntry, name, desc));
+        }
+
+        private Map<String, MethodEntry> getClassMethods(String name) {
+                return methodEntries.computeIfAbsent(name, s -> new HashMap<>());
+        }
+
+        private Map<String, FieldEntry> getClassFields(String name) {
+                return fieldEntries.computeIfAbsent(name, s -> new HashMap<>());
+        }
+}