Merge pull request #108 from NuruProgramming/fh/fix-infinite-recursion

fix: prevent infinite recursion

Author: AvicennaJr

evaluator/while.go

@@ -5,21 +5,36 @@ import (
 	"github.com/NuruProgramming/Nuru/object"
 )
 
+const MAX_ITERATIONS = 1_000_000
+
 func evalWhileExpression(we *ast.WhileExpression, env *object.Environment) object.Object {
-	condition := Eval(we.Condition, env)
 	var evaluated object.Object
-	if isError(condition) {
-		return condition
-	}
-	if isTruthy(condition) {
+	iterations := 0
+
+	for {
+		iterations++
+		if iterations > MAX_ITERATIONS {
+			return newError("mzunguko usio na mwisho umegunduliwa")
+		}
+
+		condition := Eval(we.Condition, env)
+		if isError(condition) {
+			return condition
+		}
+
+		if !isTruthy(condition) {
+			break
+		}
+
 		evaluated = Eval(we.Consequence, env)
 		if isError(evaluated) {
 			return evaluated
 		}
+
 		if evaluated != nil && evaluated.Type() == object.BREAK_OBJ {
 			return evaluated
 		}
-		evaluated = evalWhileExpression(we, env)
 	}
+
 	return evaluated
 }