add support for index operator on string

Signed-off-by: Flipez <code@brauser.io>
Flipez · Sep 28, 2021 · f7babd3 · f7babd3
1 parent aaa900e
commit f7babd3
Showing 1 changed file with 14 additions and 0 deletions.
diff --git a/evaluator/evaluator.go b/evaluator/evaluator.go
@@ -174,11 +174,25 @@ func evalIndexExpression(left, index object.Object) object.Object {
 		return evalArrayIndexExpression(left, index)
 	case left.Type() == object.HASH_OBJ:
 		return evalHashIndexExpression(left, index)
+	case left.Type() == object.STRING_OBJ:
+		return evalStringIndexExpression(left, index)
 	default:
 		return newError("index operator not supported: %s", left.Type())
 	}
 }
 
+func evalStringIndexExpression(left, index object.Object) object.Object {
+	stringObject := left.(*object.String)
+	idx := index.(*object.Integer).Value
+	max := int64(len(stringObject.Value) - 1)
+
+	if idx < 0 || idx > max {
+		return NULL
+	}
+
+	return &object.String{Value: string(stringObject.Value[idx])}
+}
+
 func evalHashIndexExpression(hash, index object.Object) object.Object {
 	hashObject := hash.(*object.Hash)
 	key, ok := index.(object.Hashable)