7 files changed, 42 insertions, 146 deletions

diff --git a/checker/src/main/java/lv/enes/orang/checker/Checker.java b/checker/src/main/java/lv/enes/orang/checker/Checker.java
index 14604b8..ee0914f 100644
--- a/checker/src/main/java/lv/enes/orang/checker/Checker.java
+++ b/checker/src/main/java/lv/enes/orang/checker/Checker.java
@@ -1,27 +1,17 @@
 package lv.enes.orang.checker;
 
 import lv.enes.orang.ast.*;
-import lv.enes.orang.core.ImmutableScope;
-import lv.enes.orang.core.Scope;
 
-import java.util.HashMap;
-import java.util.Map;
+import java.util.*;
 
 public class Checker implements ExpressionVisitor<Void, CheckerException>, StatementVisitor<Checker, CheckerException> {
-        private final Scope<Boolean> definitions;
+        private final Set<String> definitions;
 
         public static <E> Checker of(Map<String, E> builtins) {
-                var boolMap = builtins.keySet()
-                                .stream()
-                                .<Map<String, Boolean>>collect(
-                                                HashMap::new,
-                                                (map, elem) -> map.put(elem, true),
-                                                Map::putAll
-                                );
-                return new Checker(ImmutableScope.of(boolMap));
+                return new Checker(Collections.unmodifiableSet(builtins.keySet()));
         }
 
-        private Checker(Scope<Boolean> definitions) {
+        private Checker(Set<String> definitions) {
                 this.definitions = definitions;
         }
 
@@ -55,10 +45,13 @@ public class Checker implements ExpressionVisitor<Void, CheckerException>, State
 
         @Override
         public Checker visitDefinition(Definition def) throws CheckerException {
-                if (definitions.hasDefinition(def.name())) {
+                if (definitions.contains(def.name())) {
                         throw new CheckerException(STR."Top-level definition '\{def.name()}' redefined!");
                 }
-                var ch = new Checker(ImmutableScope.of(definitions, def.name(), true));
+
+                var newScope = new HashSet<>(definitions);
+                newScope.add(def.name());
+                var ch = new Checker(newScope);
                 ch.visit(def.body());
                 return ch;
         }
@@ -79,13 +72,13 @@ public class Checker implements ExpressionVisitor<Void, CheckerException>, State
 
         @Override
         public Void visitFnExpression(FnExpression expr) throws CheckerException {
-                var args = new HashMap<String, Boolean>();
+                var newScope = new HashSet<>(definitions);
                 for (var arg : expr.args()) {
                         if (arg instanceof ArgSpec.Named(String name)) {
-                                args.put(name, true);
+                                newScope.add(name);
                         }
                 }
-                new Checker(ImmutableScope.of(definitions, args)).visit(expr.body());
+                new Checker(newScope).visit(expr.body());
                 return null;
         }
 
@@ -105,11 +98,11 @@ public class Checker implements ExpressionVisitor<Void, CheckerException>, State
 
         @Override
         public Void visitLetInExpression(LetInExpression expr) throws CheckerException {
-                var locals = new HashMap<String, Boolean>();
+                var newScope = new HashSet<>(definitions);
                 for (var local : expr.bindings()) {
-                        locals.put(local.name(), true);
+                        newScope.add(local.name());
                 }
-                new Checker(ImmutableScope.of(definitions, locals)).visit(expr.body());
+                new Checker(newScope).visit(expr.body());
                 return null;
         }
 
@@ -136,7 +129,7 @@ public class Checker implements ExpressionVisitor<Void, CheckerException>, State
 
         @Override
         public Void visitVariable(VariableExpression expr) throws CheckerException {
-                if (!definitions.hasDefinition(expr.name())) {
+                if (!definitions.contains(expr.name())) {
                         throw new CheckerException(STR."Variable named '\{expr.name()}' not defined!");
                 }
                 return null;
diff --git a/core/src/main/java/lv/enes/orang/core/ImmutableScope.java b/core/src/main/java/lv/enes/orang/core/ImmutableScope.java
deleted file mode 100644
index 5120b08..0000000
--- a/core/src/main/java/lv/enes/orang/core/ImmutableScope.java
+++ /dev/null
@@ -1,47 +0,0 @@
-package lv.enes.orang.core;
-
-import java.util.HashMap;
-import java.util.Map;
-
-public class ImmutableScope<E> extends Scope<E> {
-        public static <E> ImmutableScope<E> of(Map<String, E> builtins) {
-                return new ImmutableScope<>(null, new HashMap<>(builtins));
-        }
-
-        public static <E> ImmutableScope<E> of(Scope<E> parent) {
-                if (parent instanceof ImmutableScope<E> imm) {
-                        return imm;
-                }
-                return ImmutableScope.of(parent, Map.of());
-        }
-
-        public static <E> ImmutableScope<E> of(Scope<E> parent, String key, E value) {
-                return ImmutableScope.of(parent, Map.of(key, value));
-        }
-
-        public static <E> ImmutableScope<E> of(Scope<E> parent, Map<String, E> definitions) {
-                return new ImmutableScope<>(parent, definitions).maybeFlattened();
-        }
-
-        protected ImmutableScope(Scope<E> parent, Map<String, E> definitions) {
-                super(parent, Map.copyOf(definitions));
-        }
-
-        public ImmutableScope<E> maybeFlattened() {
-                if (depth > MAX_DEPTH) {
-                        return flattened();
-                }
-                return this;
-        }
-
-        private ImmutableScope<E> flattened() {
-                if (parent instanceof ImmutableScope<E> immParent) {
-                        var flatParent = immParent.flattened();
-                        var newDefs = new HashMap<>(flatParent.definitions);
-                        newDefs.putAll(definitions);
-                        return new ImmutableScope<>(flatParent.parent, newDefs);
-                }
-
-                return this;
-        }
-}
diff --git a/core/src/main/java/lv/enes/orang/core/MutableScope.java b/core/src/main/java/lv/enes/orang/core/MutableScope.java
deleted file mode 100644
index 8d8b455..0000000
--- a/core/src/main/java/lv/enes/orang/core/MutableScope.java
+++ /dev/null
@@ -1,26 +0,0 @@
-package lv.enes.orang.core;
-
-import java.util.HashMap;
-import java.util.Map;
-
-public class MutableScope<E> extends Scope<E> {
-        public static <E> MutableScope<E> of(Map<String, E> builtins) {
-                return new MutableScope<>(null, new HashMap<>(builtins));
-        }
-
-        public static <E> MutableScope<E> of(Scope<E> parent) {
-                return new MutableScope<>(parent, Map.of());
-        }
-
-        public static <E> MutableScope<E> of(Scope<E> parent, String name, E value) {
-                return new MutableScope<>(parent, Map.of(name, value));
-        }
-
-        protected MutableScope(Scope<E> parent, Map<String, E> definitions) {
-                super(parent, new HashMap<>(definitions));
-        }
-
-        public void setDefinition(String key, E value) {
-                definitions.put(key, value);
-        }
-}
diff --git a/core/src/main/java/lv/enes/orang/core/Scope.java b/core/src/main/java/lv/enes/orang/core/Scope.java
deleted file mode 100644
index 0f4d23a..0000000
--- a/core/src/main/java/lv/enes/orang/core/Scope.java
+++ /dev/null
@@ -1,31 +0,0 @@
-package lv.enes.orang.core;
-
-import java.util.Map;
-
-public abstract class Scope<E> {
-        public static final int MAX_DEPTH = 4;
-
-        protected final Scope<E> parent;
-        protected final Map<String, E> definitions;
-        protected final int depth;
-
-        protected Scope(Scope<E> parent, Map<String, E> definitions) {
-                this.parent = parent;
-                this.definitions = definitions;
-                this.depth = parent == null ? 0 : parent.depth + 1;
-        }
-
-        public E getDefinition(String name) throws OrangRuntimeException {
-                if (definitions.containsKey(name)) {
-                        return definitions.get(name);
-                } else if (parent != null) {
-                        return parent.getDefinition(name);
-                } else {
-                        throw new OrangRuntimeException(STR."Value named \{name} is not defined!");
-                }
-        }
-
-        public boolean hasDefinition(String name) {
-                return definitions.containsKey(name) || parent != null && parent.hasDefinition(name);
-        }
-}
diff --git a/orang/src/main/java/lv/enes/orang/Evaluator.java b/orang/src/main/java/lv/enes/orang/Evaluator.java
index 8930f5c..69a256f 100644
--- a/orang/src/main/java/lv/enes/orang/Evaluator.java
+++ b/orang/src/main/java/lv/enes/orang/Evaluator.java
@@ -1,20 +1,20 @@
 package lv.enes.orang;
 
 import lv.enes.orang.ast.*;
-import lv.enes.orang.core.MutableScope;
 import lv.enes.orang.core.OrangRuntimeException;
-import lv.enes.orang.core.Scope;
 import lv.enes.orang.value.*;
 
 import java.util.ArrayList;
 import java.util.Collections;
+import java.util.HashMap;
+import java.util.Map;
 
-public record Evaluator(Scope<Value> scope, Value lastResult) implements ExpressionVisitor<Value, OrangRuntimeException>, StatementVisitor<Evaluator, OrangRuntimeException> {
+public record Evaluator(Map<String, Value> scope, Value lastResult) implements ExpressionVisitor<Value, OrangRuntimeException>, StatementVisitor<Evaluator, OrangRuntimeException> {
         public Evaluator() {
-                this(MutableScope.of(Builtins.BUILTINS));
+                this(new HashMap<>(Builtins.BUILTINS));
         }
 
-        public Evaluator(Scope<Value> scope) {
+        public Evaluator(Map<String, Value> scope) {
                 this(scope, Undefined.INSTANCE);
         }
 
@@ -59,9 +59,10 @@ public record Evaluator(Scope<Value> scope, Value lastResult) implements Express
 
         @Override
         public Evaluator visitDefinition(Definition def) throws OrangRuntimeException {
-                var newScope = MutableScope.of(scope, def.name(), Undefined.INSTANCE);
+                var newScope = new HashMap<>(scope);
+                newScope.put(def.name(), Undefined.INSTANCE);
                 var newEvaluator = new Evaluator(newScope);
-                newScope.setDefinition(def.name(), newEvaluator.visit(def.body()));
+                newScope.put(def.name(), newEvaluator.visit(def.body()));
                 return newEvaluator;
         }
 
@@ -105,13 +106,13 @@ public record Evaluator(Scope<Value> scope, Value lastResult) implements Express
 
         @Override
         public Value visitLetInExpression(LetInExpression expr) throws OrangRuntimeException {
-                var newScope = MutableScope.of(scope);
+                var newScope = new HashMap<>(scope);
                 for (var binding : expr.bindings()) {
-                        newScope.setDefinition(binding.name(), Undefined.INSTANCE);
+                        newScope.put(binding.name(), Undefined.INSTANCE);
                 }
                 var newEvaluator = new Evaluator(newScope);
                 for (var binding : expr.bindings()) {
-                        newScope.setDefinition(binding.name(), newEvaluator.visit(binding.value()));
+                        newScope.put(binding.name(), newEvaluator.visit(binding.value()));
                 }
                 return newEvaluator.visit(expr.body());
         }
@@ -142,7 +143,11 @@ public record Evaluator(Scope<Value> scope, Value lastResult) implements Express
 
         @Override
         public Value visitVariable(VariableExpression expr) throws OrangRuntimeException {
-                return scope.getDefinition(expr.name());
+                if (scope.containsKey(expr.name())) {
+                        return scope.get(expr.name());
+                }
+
+                throw new OrangRuntimeException(STR."Value named \{expr.name()} is not defined!");
         }
 
         @Override
diff --git a/orang/src/main/java/lv/enes/orang/value/Function.java b/orang/src/main/java/lv/enes/orang/value/Function.java
index d0500b9..f8c1a7f 100644
--- a/orang/src/main/java/lv/enes/orang/value/Function.java
+++ b/orang/src/main/java/lv/enes/orang/value/Function.java
@@ -3,10 +3,11 @@ package lv.enes.orang.value;
 import lv.enes.orang.ast.ArgSpec;
 import lv.enes.orang.ast.Expression;
 import lv.enes.orang.core.OrangRuntimeException;
-import lv.enes.orang.core.Scope;
 import lv.enes.orang.utils.NonEmptyList;
 
-public record Function(Scope<Value> scope, NonEmptyList<ArgSpec> args, Expression body) implements Value {
+import java.util.Map;
+
+public record Function(Map<String, Value> scope, NonEmptyList<ArgSpec> args, Expression body) implements Value {
         @Override
         public String typeName() {
                 return "Function";
diff --git a/orang/src/main/java/lv/enes/orang/value/PartialFunction.java b/orang/src/main/java/lv/enes/orang/value/PartialFunction.java
index d03bb13..427da76 100644
--- a/orang/src/main/java/lv/enes/orang/value/PartialFunction.java
+++ b/orang/src/main/java/lv/enes/orang/value/PartialFunction.java
@@ -3,17 +3,18 @@ package lv.enes.orang.value;
 import lv.enes.orang.*;
 import lv.enes.orang.ast.ArgSpec;
 import lv.enes.orang.ast.Expression;
-import lv.enes.orang.core.MutableScope;
 import lv.enes.orang.core.OrangRuntimeException;
-import lv.enes.orang.core.Scope;
 import lv.enes.orang.utils.NonEmptyList;
 
-public record PartialFunction(Scope<Value> scope, NonEmptyList<ArgSpec> remainingArgs, Expression body) implements Value {
-        public static Value of(Scope<Value> scope, NonEmptyList<ArgSpec> remainingArgs, Expression body, Value param) throws OrangRuntimeException {
+import java.util.HashMap;
+import java.util.Map;
+
+public record PartialFunction(Map<String, Value> scope, NonEmptyList<ArgSpec> remainingArgs, Expression body) implements Value {
+        public static Value of(Map<String, Value> scope, NonEmptyList<ArgSpec> remainingArgs, Expression body, Value param) throws OrangRuntimeException {
                 var spec = remainingArgs.getFirst();
-                var newScope = MutableScope.of(scope);
+                var newScope = new HashMap<>(scope);
                 switch (spec.getType()) {
-                        case NAMED -> newScope.setDefinition(((ArgSpec.Named)spec).name(), param);
+                        case NAMED -> newScope.put(((ArgSpec.Named)spec).name(), param);
                         case NOTHING -> {
                                 if (!(param instanceof Nothing)) {
                                         throw new OrangRuntimeException(STR."Expected () as a parameter but got \{param.typeName()}");