✨ Interpreter support for while loops

Author: igorkulman

PascalInterpreter/PascalInterpreter/Interpreter/Interpreter.swift

@@ -48,6 +48,8 @@ public class Interpreter {
             return eval(ifElse: ifElse)
         case let repeatUntil as RepeatUntil:
             return eval(repeatUntil: repeatUntil)
+        case let whileLoop as While:
+            return eval(whileLoop: whileLoop)
         case let forLoop as For:
             return eval(forLoop: forLoop)
         default:
@@ -182,6 +184,14 @@ public class Interpreter {
         return .none
     }
 
+    func eval(whileLoop: While) -> Value {
+        while case .boolean(true) = eval(condition: whileLoop.condition) {
+            eval(node: whileLoop.statement)
+        }
+
+        return .none
+    }
+
     func eval(forLoop: For) -> Value {
         guard let currentFrame = callStack.peek() else {
             fatalError("No call stack frame")