4 files changed, 52 insertions, 0 deletions

diff --git a/chunk.d b/chunk.d
index 7a532f5..68df45b 100644
--- a/chunk.d
+++ b/chunk.d
@@ -139,6 +139,7 @@ enum OpCode {
     OP_ADD,
     OP_LESS,
     OP_NOT,
+    OP_EQUAL,
     OP_GREATER,
     OP_NEGATE,
     OP_RETURN,
diff --git a/compiler.d b/compiler.d
index eccc4ce..4fb37f2 100644
--- a/compiler.d
+++ b/compiler.d
@@ -304,6 +304,20 @@ class Compiler {
         return ValueType.BOOLEAN;
     }
 
+    ValueType compileEq(Form[] args) {
+        if (args.length != 2) {
+            this.error(format("'eq?': expected [1] argument, received %d", to!int(args.length)), -1);
+            this.advance();
+            return ValueType.NIL;
+        }
+        ValueType vt1 = this.resolve(args[0], ValueType.ANY);
+        ValueType vt2 = this.resolve(args[1], ValueType.ANY);
+
+        this.func.chunk.writeOp(OpCode.OP_EQUAL, args[1].line);
+
+        return ValueType.BOOLEAN;
+    }
+
 
     //int parseVariable(Def def) {
     int parseVariable(Symbol sym) {
@@ -726,6 +740,8 @@ class Compiler {
                     return this.compileSubtract(cons.tail, ValueType.NUMBER);
                 }
                 break;
+
+            // BOOLEAN
             case "<":
                 return this.compileLess(cons.tail, ValueType.NUMBER);
                 break;
@@ -742,6 +758,8 @@ class Compiler {
                 return vt;
             case "not":
                 return this.compileNot(cons.tail);
+            case "eq?":
+                return this.compileEq(cons.tail);
 
             // STRINGS
             case "concat":
diff --git a/parser.d b/parser.d
index 6974662..440cae0 100644
--- a/parser.d
+++ b/parser.d
@@ -320,6 +320,34 @@ struct Value {
     As as;
 }
 
+bool areValuesEqual(Value left, Value right) {
+    if (left.type != right.type) {
+        return false;
+    }
+
+    switch (left.type) {
+        case ValueType.NUMBER:
+            return left.as.number == right.as.number;
+        case ValueType.BOOLEAN:
+            return left.as.boolean == right.as.boolean;
+        case ValueType.SEQ:
+            Seq leftSeq = cast(Seq)left.as.seq;
+            Seq rightSeq = cast(Seq)right.as.seq;
+            if (leftSeq.type != rightSeq.type) {
+                return false;
+            } else if (leftSeq.type == SeqType.STRING) {
+                return (cast(String)leftSeq).str == (cast(String)rightSeq).str;
+            } else {
+                // NOTE if eq? should work for lists, that logic goes here
+                return false;
+            }
+        default:
+            writeln("!!! THIS VALUE TYPE IS NOT SUPPORTED BY eq?");
+            return false;
+    }
+
+}
+
 Value makeStringValue(string str) {
     As as = { str: str };
     Value val = { ValueType.STRING, as };
diff --git a/vm.d b/vm.d
index dcacd28..c7e5e8e 100644
--- a/vm.d
+++ b/vm.d
@@ -447,6 +447,11 @@ class VM {
                     bool bval = asBoolean(val);
                     this.pushA(makeBooleanValue(!bval));
                     break;
+                case OpCode.OP_EQUAL:
+                    Value b = this.popA();
+                    Value a = this.popA();
+                    this.pushA(makeBooleanValue(areValuesEqual(a, b)));
+                    break;
                 case OpCode.OP_CONCAT:
                     Seq b = asSeq(this.popA());
                     Seq a = asSeq(this.popA());