Added a checker module.

NOTE: I think I should look at guava or commons for some sort of sealable Map instead of the current Scope :D

4 files changed, 115 insertions, 0 deletions

diff --git a/core/src/main/java/lv/enes/orang/core/ImmutableScope.java b/core/src/main/java/lv/enes/orang/core/ImmutableScope.java
new file mode 100644
index 0000000..5120b08
--- /dev/null
+++ b/core/src/main/java/lv/enes/orang/core/ImmutableScope.java
@@ -0,0 +1,47 @@
+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
new file mode 100644
index 0000000..8d8b455
--- /dev/null
+++ b/core/src/main/java/lv/enes/orang/core/MutableScope.java
@@ -0,0 +1,26 @@
+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/OrangRuntimeException.java b/core/src/main/java/lv/enes/orang/core/OrangRuntimeException.java
new file mode 100644
index 0000000..6ce5f70
--- /dev/null
+++ b/core/src/main/java/lv/enes/orang/core/OrangRuntimeException.java
@@ -0,0 +1,11 @@
+package lv.enes.orang.core;
+
+public class OrangRuntimeException extends OrangException {
+        public OrangRuntimeException(String message) {
+                super(message);
+        }
+
+        public OrangRuntimeException(Throwable cause) {
+                super(cause);
+        }
+}
diff --git a/core/src/main/java/lv/enes/orang/core/Scope.java b/core/src/main/java/lv/enes/orang/core/Scope.java
new file mode 100644
index 0000000..0f4d23a
--- /dev/null
+++ b/core/src/main/java/lv/enes/orang/core/Scope.java
@@ -0,0 +1,31 @@
+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);
+        }
+}