Eval Infix Integer Operator

2 files changed, 43 insertions, 0 deletions

diff --git a/evaluator/evaluator.go b/evaluator/evaluator.go
index b8940a9..5d69e2b 100644
--- a/evaluator/evaluator.go
+++ b/evaluator/evaluator.go
@@ -31,6 +31,11 @@ func Eval(node ast.Node) object.Object {
 	case *ast.PrefixExpression:
 		right := Eval(node.Right)
 		return evalPrefixExpression(node.Operator, right)
+	
+	case *ast.InfixExpression:
+		left := Eval(node.Left)
+		right := Eval(node.Right)
+		return evalInfixExpression(node.Operator, left, right)
 	}
 
 	return nil
@@ -64,6 +69,15 @@ func evalPrefixExpression(operator string, right object.Object) object.Object {
 	}
 }
 
+func evalInfixExpression(operator string, left, right object.Object) object.Object {
+	switch {
+	case left.Type() == object.INTEGER_OBJ && right.Type() == object.INTEGER_OBJ:
+		return evalIntegerInfixExpression(operator, left, right)
+	default:
+		return NULL
+	}
+}
+
 func evalBangOperatorExpression(right object.Object) object.Object {
 	switch right {
 	case TRUE:
@@ -85,3 +99,21 @@ func evalMinusPrefixOperatorExpression(right object.Object) object.Object {
 	value := right.(*object.Integer).Value
 	return &object.Integer{Value: -value}
 }
+
+func evalIntegerInfixExpression(operator string, left, right object.Object) object.Object {
+	leftValue := left.(*object.Integer).Value
+	rightValue := right.(*object.Integer).Value
+
+	switch operator {
+	case "+":
+		return &object.Integer{Value: leftValue + rightValue}
+	case "-":
+		return &object.Integer{Value: leftValue - rightValue}
+	case "*":
+		return &object.Integer{Value: leftValue * rightValue}
+	case "/":
+		return &object.Integer{Value: leftValue / rightValue}
+	default:
+		return NULL
+	}
+}
diff --git a/evaluator/evaluator_test.go b/evaluator/evaluator_test.go
index 1221de6..f0a5180 100644
--- a/evaluator/evaluator_test.go
+++ b/evaluator/evaluator_test.go
@@ -17,6 +17,17 @@ func TestEvalIntegerExpression(t *testing.T) {
 		{"10", 10},
 		{"-5", -5},
 		{"-10", -10},
+		{"5 + 5 + 5 + 5 - 10", 10},
+		{"2 * 2 * 2 * 2 * 2", 32},
+		{"-50 + 100 + -50", 0},
+		{"5 * 2 + 10", 20},
+		{"5 + 2 * 10", 25},
+		{"20 + 2 * -10", 0},
+		{"50 / 2 * 2 + 10", 60},
+		{"2 * (5 + 10)", 30},
+		{"3 * 3 * 3 + 10", 37},
+		{"3 * (3 * 3) + 10", 37},
+		{"(5 + 10 * 2 + 15 / 3) * 2 + -10", 50},
 	}
 
 	for _, tt := range tests {