1 files changed, 47 insertions, 0 deletions
diff --git a/evaluator/evaluator.go b/evaluator/evaluator.go
index 913138b..5e988cc 100644
--- a/evaluator/evaluator.go
+++ b/evaluator/evaluator.go
@@ -110,6 +110,9 @@ func Eval(node ast.Node, env *object.Environment) object.Object {
 	case *ast.StringLiteral:
 		return &object.String{Value: node.Value}
 
+	case *ast.HashLiteral:
+		return evalHashLiteral(node, env)
+
 	case *ast.ReturnStatement:
 		val := Eval(node.ReturnValue, env)
 		if isError(val) {
@@ -319,6 +322,8 @@ func evalIndexExpression(left, index object.Object) object.Object {
 	switch {
 	case left.Type() == object.ARRAY_OBJ && index.Type() == object.INTEGER_OBJ:
 		return evalArrayIndexExpression(left, index)
+	case left.Type() == object.HASH_OBJ:
+		return evalHashIndexExpression(left, index)
 	default:
 		return newError("index operator not supported: %s", left.Type())
 	}
@@ -348,6 +353,48 @@ func evalIdentifier(node *ast.Identifier, env *object.Environment) object.Object
 	return newError("identifier not found: " + node.Value)
 }
 
+func evalHashLiteral(node *ast.HashLiteral, env *object.Environment) object.Object {
+	pairs := make(map[object.HashKey]object.HashPair)
+
+	for keyNode, valueNode := range node.Pairs {
+		key := Eval(keyNode, env)
+		if isError(key) {
+			return key
+		}
+
+		hashKey, ok := key.(object.Hashable)
+		if !ok {
+			return newError("unusable as hash key: %s", key.Type())
+		}
+
+		value := Eval(valueNode, env)
+		if isError(value) {
+			return value
+		}
+
+		hashed := hashKey.HashKey()
+		pairs[hashed] = object.HashPair{Key: key, Value: value}
+	}
+
+	return &object.Hash{Pairs: pairs}
+}
+
+func evalHashIndexExpression(hash, index object.Object) object.Object {
+	hashObject := hash.(*object.Hash)
+
+	key, ok := index.(object.Hashable)
+	if !ok {
+		return newError("unusable as hash key: %s", index.Type())
+	}
+
+	pair, ok := hashObject.Pairs[key.HashKey()]
+	if !ok {
+		return NULL
+	}
+
+	return pair.Value
+}
+
 func isTruthy(obj object.Object) bool {
 	switch obj {
 	case NULL: