changed "repeat until" loop to "repeat times"

Added setBackground function
Renamed setStepDuration to setStep

LanguageInterpreter/Execution/ExpressionEvaluator.cs

@@ -290,20 +290,22 @@ public Result<SyntaxException, object> Evaluate(CancellationToken token)
             return null;
         }
 
-        object? value;
+        object? value = Empty.Instance;
+
+        if (Visit(expression.CountExpression, token) is not double count)
+            return null;
+
+        int i = 0;
 
         while (true)
         {
+            if (i >= count)
+                break;
+            i++;
+
             value = Visit(expression.Body, token);
             if (value is null)
                 return null;
-
-            var condition = Visit(expression.Condition, token);
-            if (condition is null)
-                return null;
-
-            if ((bool)condition)
-                break;
         }
 
         return value;

LanguageInterpreter/Execution/TypeResolver.cs

@@ -279,14 +279,14 @@ public Result<SyntaxException, Type> Resolve(CancellationToken token)
             return null;
         }
 
-        var conditionType = Visit(expression.Condition, token);
+        var countType = Visit(expression.CountExpression, token);
 
-        if (conditionType is null)
+        if (countType is null)
             return null;
 
-        if (conditionType != typeof(bool))
+        if (countType != typeof(double))
         {
-            _errors.Add(new ExpectedOtherTypeException(expression.Condition, conditionType, typeof(bool)));
+            _errors.Add(new ExpectedOtherTypeException(expression.CountExpression, countType, typeof(double)));
             return null;
         }
 

LanguageParser.Tests/UnitTest1.cs

@@ -247,8 +247,8 @@ public void CanParseRepeatExpression()
     {
         var texts = new[]
         {
-            "repeat expression() until (true)", "repeat { expression() foo(e, a) 5 - 8 } until (true)",
-            "repeat expression(); until (true);", "repeat { expression(); foo(e, a); 5 - 8; } until (true);"
+            "repeat count() times expression()", "repeat  50 times { expression() foo(e, a) 5 - 8 }",
+            "repeat count(); times expression();", "repeat 50; times { expression(); foo(e, a); 5 - 8; };"
         };
 
         foreach (var text in texts)
@@ -355,7 +355,7 @@ public void CanParseSequenceOfExpressions()
     public void CanParseComplexString()
     {
         var text =
-            "number a;\nnumber b;\n\nstring arg1;\n\nstring arg2 = \"some string;\"\n\nbool boolValue = false \n    \nsomeFunction(arg1, arg2)\n\nif (boolValue)\n    arg1 = someFunction2(arg)\n\nif (false)\n    a = someFunction3(arg)\nelse\n    b = someFunction4(arg)\n\nif (predicat())\n    print(\"Hello, world\")\n\nwhile(true)\n{\n    Function1()\n    Function2()\n    Function3()\n    number c = (4 + 3) * 2.5 - 38 / 2\n}\n\nfor (;;)\n{\n    ForBody()\n}\n\nrepeat Expression() until (true)\n\nfor (i = 0; i <= 23; i = i + 1)\n    ForBody()\n\nfor (;i > 0;)\n{}\n\n{\n    Expression1()\n    Expression2()\n\n    a + b + 4\n}\n\nif (1)\n    if (2)\n        DoSomething()\n    else\n        if (3)\n            doOther()\n        else\n            print(\"String\")\n\n\nif (1)\n{\n    if (2)\n        DoSomething()\n    else\n        if (3)\n            doOther()\n}\nelse\n    print(\"String\")";
+            "number a;\nnumber b;\n\nstring arg1;\n\nstring arg2 = \"some string;\"\n\nbool boolValue = false \n    \nsomeFunction(arg1, arg2)\n\nif (boolValue)\n    arg1 = someFunction2(arg)\n\nif (false)\n    a = someFunction3(arg)\nelse\n    b = someFunction4(arg)\n\nif (predicat())\n    print(\"Hello, world\")\n\nwhile(true)\n{\n    Function1()\n    Function2()\n    Function3()\n    number c = (4 + 3) * 2.5 - 38 / 2\n}\n\nfor (;;)\n{\n    ForBody()\n}\n\nrepeat 100 times Expression()\n\nfor (i = 0; i <= 23; i = i + 1)\n    ForBody()\n\nfor (;i > 0;)\n{}\n\n{\n    Expression1()\n    Expression2()\n\n    a + b + 4\n}\n\nif (1)\n    if (2)\n        DoSomething()\n    else\n        if (3)\n            doOther()\n        else\n            print(\"String\")\n\n\nif (1)\n{\n    if (2)\n        DoSomething()\n    else\n        if (3)\n            doOther()\n}\nelse\n    print(\"String\")";
 
         _testOutputHelper.WriteLine(text);
 
@@ -375,7 +375,7 @@ public void CanParseComplexString()
     public void CanParseComplexStringWithSemicolons()
     {
         var text =
-            "number a;\nnumber b;\n\nstring arg1;\n\nstring arg2 = \"some string\";\n\nbool boolValue = false; \n    \nsomeFunction(arg1, arg2);\n\nif (boolValue)\n    arg1 = someFunction2(arg);\n\nif (false)\n    a = someFunction3(arg);\nelse\n    b = someFunction4(arg);\n\nif (predicat())\n    print(\"Hello, world\");\n\nwhile(true)\n{\n    Function1();\n    Function2();\n    Function3();\n    number c = (4 + 3) * 2.5 - 38 / 2;\n}\n\nfor (;;)\n{\n    ForBody();\n}\n\nrepeat Expression() until (true)\n\nfor (i = 0; i <= 23; i = i + 1)\n    ForBody();\n\nfor (;i > 0;)\n{}\n\n{\n    Expression1();\n    Expression2();\n\n    a + b + 4;\n}\n\nif (1)\n    if (2)\n        DoSomething();\n    else\n        if (3)\n            doOther();\n        else\n            print(\"String\");\n\n\nif (1)\n{\n    if (2)\n        DoSomething();\n    else\n        if (3)\n            doOther();\n}\nelse\n    print(\"String\");";
+            "number a;\nnumber b;\n\nstring arg1;\n\nstring arg2 = \"some string\";\n\nbool boolValue = false; \n    \nsomeFunction(arg1, arg2);\n\nif (boolValue)\n    arg1 = someFunction2(arg);\n\nif (false)\n    a = someFunction3(arg);\nelse\n    b = someFunction4(arg);\n\nif (predicat())\n    print(\"Hello, world\");\n\nwhile(true)\n{\n    Function1();\n    Function2();\n    Function3();\n    number c = (4 + 3) * 2.5 - 38 / 2;\n}\n\nfor (;;)\n{\n    ForBody();\n}\n\nrepeat 100 times Expression()\n\nfor (i = 0; i <= 23; i = i + 1)\n    ForBody();\n\nfor (;i > 0;)\n{}\n\n{\n    Expression1();\n    Expression2();\n\n    a + b + 4;\n}\n\nif (1)\n    if (2)\n        DoSomething();\n    else\n        if (3)\n            doOther();\n        else\n            print(\"String\");\n\n\nif (1)\n{\n    if (2)\n        DoSomething();\n    else\n        if (3)\n            doOther();\n}\nelse\n    print(\"String\");";
 
         _testOutputHelper.WriteLine(text);
 
@@ -671,7 +671,7 @@ public void CanUsePredefinedFunctionsAndVariablesInLoops()
         Assert.NotNull(interpreter);
 
         const string text =
-            "print(\"start\")\n\nnumber someNumber = 6\n\nfor (number i = 0; i < someNumber; i = i + 1)\n    print(\"current i = \" + i)\n\nnumber i = 0\n\nwhile (i > someNumber / 2)\n{\n    print(i + \": PI still equals \" + PI)\n\n    i = i - 1\n}\n\nnumber j = 0\n\nrepeat\n{\n    print(\"Repeat print E\")\n    print(E)\n\n    j = j + 1\n} until (j >= 5)\n\nprint(\"done\")";
+            "print(\"start\")\n\nnumber someNumber = 6\n\nfor (number i = 0; i < someNumber; i = i + 1)\n    print(\"current i = \" + i)\n\nnumber i = 0\n\nwhile (i > someNumber / 2)\n{\n    print(i + \": PI still equals \" + PI)\n\n    i = i - 1\n}\n\nnumber j = 0\n\nrepeat 5 times\n{\n    print(\"Repeat print E\")\n    print(E)\n}\nprint(\"done\")";
 
         _testOutputHelper.WriteLine(text);
         _testOutputHelper.WriteLine("\nresult:\n");

LanguageParser/Common/SyntaxKind.cs

@@ -100,9 +100,9 @@ public enum SyntaxKind
     /// </summary>
     Repeat,
     /// <summary>
-    /// until keyword
+    /// times keyword
     /// </summary>
-    Until,
+    Times,
     /// <summary>
     /// for keyword
     /// </summary>

LanguageParser/Expressions/RepeatExpression.cs

@@ -7,32 +7,25 @@ namespace LanguageParser.Expressions;
 
 public sealed class RepeatExpression : ExpressionBase
 {
-    internal RepeatExpression(Token repeatToken, ExpressionBase body, Token untilToken, Token openParenthesis,
-        ExpressionBase condition, Token closeParenthesis) : base(SyntaxKind.RepeatExpression)
+    internal RepeatExpression(Token repeatToken, ExpressionBase countExpression, Token timesToken, ExpressionBase body) : base(SyntaxKind.RepeatExpression)
     {
         RepeatToken = repeatToken;
+        CountExpression = countExpression;
+        TimesToken = timesToken;
         Body = body;
-        UntilToken = untilToken;
-        OpenParenthesis = openParenthesis;
-        Condition = condition;
-        CloseParenthesis = closeParenthesis;
     }
 
     public Token RepeatToken { get; }
+    public ExpressionBase CountExpression { get; }
+    public Token TimesToken { get; }
     public ExpressionBase Body { get; }
-    public Token UntilToken { get; }
-    public Token OpenParenthesis { get; }
-    public ExpressionBase Condition { get; }
-    public Token CloseParenthesis { get; }
 
     public override IEnumerable<ISyntaxElement> GetAllElements()
     {
         yield return RepeatToken;
+        yield return CountExpression;
+        yield return TimesToken;
         yield return Body;
-        yield return UntilToken;
-        yield return OpenParenthesis;
-        yield return Condition;
-        yield return CloseParenthesis;
     }
 
     public override void Visit(ExpressionVisitor visitor)

LanguageParser/Lexer/Syntax.cs

@@ -27,7 +27,7 @@ public static string GetLexemeForToken(SyntaxKind kind)
             SyntaxKind.If => "if",
             SyntaxKind.Else => "else",
             SyntaxKind.Repeat => "repeat",
-            SyntaxKind.Until => "until",
+            SyntaxKind.Times => "times",
             SyntaxKind.While => "while",
             SyntaxKind.For => "for",
             SyntaxKind.Number => "number",

LanguageParser/Lexer/Tokenizer.cs

@@ -80,14 +80,14 @@ private Token ReadToken()
         }
     }
 
-    private Token AdjustKeyword(Token token)
+    private static Token AdjustKeyword(Token token)
     {
         return token.Lexeme switch
         {
             "if" => new Token(SyntaxKind.If, token.Lexeme, token.Range.Start),
             "else" => new Token(SyntaxKind.Else, token.Lexeme, token.Range.Start),
             "repeat" => new Token(SyntaxKind.Repeat, token.Lexeme, token.Range.Start),
-            "until" => new Token(SyntaxKind.Until, token.Lexeme, token.Range.Start),
+            "times" => new Token(SyntaxKind.Times, token.Lexeme, token.Range.Start),
             "while" => new Token(SyntaxKind.While, token.Lexeme, token.Range.Start),
             "for" => new Token(SyntaxKind.For, token.Lexeme, token.Range.Start),
             "number" => new Token(SyntaxKind.Number, token.Lexeme, token.Range.Start),

LanguageParser/Parser/ExpressionsParser.cs

@@ -333,27 +333,19 @@ private bool TryParseSeparated(SyntaxKind open, SyntaxKind close, SyntaxKind sep
         if (repeatToken is null)
             return null;
 
-        var body = ParseExpression();
-        if (body is null) 
-            return null;
-
-        var untilToken = EatToken(SyntaxKind.Until);
-        if (untilToken is null)
-            return null;
-
-        var openToken = EatToken(SyntaxKind.OpenParenthesis);
-        if (openToken is null)
+        var count = ParseExpression();
+        if (count is null)
             return null;
 
-        var condition = ParseExpression();
-        if (condition is null)
+        var timesToken = EatToken(SyntaxKind.Times);
+        if (timesToken is null)
             return null;
-
-        var closeToken = EatToken(SyntaxKind.CloseParenthesis);
-        if (closeToken is null)
+        
+        var body = ParseExpression();
+        if (body is null) 
             return null;
 
-        return new RepeatExpression(repeatToken, body, untilToken, openToken, condition, closeToken);
+        return new RepeatExpression(repeatToken, count, timesToken, body);
     }
 
     private ExpressionBase? ParseWhileExpression()

LanguageParser/Visitors/ExpressionWalker.cs

@@ -47,8 +47,8 @@ public override void VisitParenthesized(ParenthesizedExpression expression)
 
     public override void VisitRepeat(RepeatExpression expression)
     {
+        Visit(expression.CountExpression);
         Visit(expression.Body);
-        Visit(expression.Condition);
     }
 
     public override void VisitScope(ScopeExpression expression)

SimpleExecutor/Models/ExpressionsColorizer.cs

@@ -98,11 +98,11 @@ public override void VisitRepeat(RepeatExpression expression)
     {
         SetForeground(expression.RepeatToken, KeywordBrush);
 
-        Visit(expression.Body);
-
-        SetForeground(expression.UntilToken, KeywordBrush);
+        Visit(expression.CountExpression);
+        
+        SetForeground(expression.TimesToken, KeywordBrush);
 
-        Visit(expression.Condition);
+        Visit(expression.Body);
     }
 
     public override void VisitScope(ScopeExpression expression)

SimpleExecutor/ViewModels/MainViewModel.cs

@@ -75,15 +75,22 @@ public MainViewModel()
             Task.Delay((int)time).Wait();
         });
 
-        var setStepDurationFunction = new Function("setStepDuration",
+        var setStepFunction = new Function("setStep",
             new[] { new Variable("milliseconds", typeof(double)) },
             args => { StepDuration = (int)(double)args[0]; });
 
         var setColorFunction = new Function("setColor", new[] { new Variable("color", typeof(string)) }, args =>
         {
             var brush = (ISolidColorBrush)Brush.Parse((string)args[0]);
 
-            Executor.TraceColor = (IImmutableSolidColorBrush)brush.ToImmutable();
+            Dispatcher.UIThread.Invoke(() => Executor.TraceColor = (IImmutableSolidColorBrush) brush.ToImmutable());
+        });
+
+        var setBackgroundFunction = new Function("setBackground", new[] {new Variable("color", typeof(string))}, args =>
+        {
+            var brush = (ISolidColorBrush)Brush.Parse((string)args[0]);
+
+            Dispatcher.UIThread.Invoke(() => Executor.Background = (IImmutableSolidColorBrush) brush.ToImmutable());
         });
 
         TokensSyntaxColorizer = new TokensSyntaxColorizer(this);
@@ -99,8 +106,9 @@ public MainViewModel()
             .WithPredefinedFunction(resetFunction)
             .WithPredefinedFunction(jumpFunction)
             .WithPredefinedFunction(delayFunction)
-            .WithPredefinedFunction(setStepDurationFunction)
+            .WithPredefinedFunction(setStepFunction)
             .WithPredefinedFunction(setColorFunction)
+            .WithPredefinedFunction(setBackgroundFunction)
             .WithPredefinedFunction(widthFunction)
             .WithPredefinedFunction(heightFunction)
             .WithPredefinedFunction(timeFunction)
@@ -261,4 +269,28 @@ public string Output
 //     y = y + velocityY * deltaTime;
 // 	
 //     jump(x, y);
+// }
+
+// reset()
+// setBackground('black')
+// setStep(10)
+// setColor('transparent')
+// jump(getWidth() * 0.5, getHeight() * 0.5)
+//
+// for (number i = 0; i <= 500; i = i + 1)
+// {
+//     if (i % 6 == 0)
+//         setColor('yellow')
+//     else if (i % 5 == 0)
+//         setColor('orange')
+//     else if (i % 4 == 0)
+//         setColor('green')
+//     else if (i % 3 == 0)
+//         setColor('blue')
+//     else if (i % 2 == 0)
+//         setColor('purple')
+//     else setColor('red')
+// 	
+//     move(i)
+//     rotate(59)	
 // }

SimpleExecutor/Views/ExecutorView.axaml.cs

@@ -60,6 +60,11 @@ private void OnRender(SKCanvas canvas, SKSurface surface)
             return;
 
         using var paint = new SKPaint();
+
+        paint.Color = _executor.Background.Color.ToSKColor();
+
+        canvas.DrawRect(Bounds.ToSKRect(), paint);
+
         paint.IsAntialias = true;
 
         paint.StrokeWidth = 2;