Better error reporter

Upsilon/Binder/Binder.cs

@@ -131,7 +131,7 @@ namespace Upsilon.Binder
                 case SyntaxKind.FunctionExpression:
                     return BindFunctionExpression((FunctionExpressionSyntax) e);
                 case SyntaxKind.BadExpression:
-                    return new BoundLiteralExpression(new ScriptNull(), e.Span);
+                    return new BoundBadExpression(e.Span);
                 case SyntaxKind.ScriptUnit:
                     break;
                 default:
@@ -143,6 +143,8 @@ namespace Upsilon.Binder
         private BoundExpression BindUnaryExpression(UnaryExpressionSyntax e)
         {
             var inExp  = BindExpression(e.Expression);
+            if (inExp.Kind == BoundKind.BoundBadExpression)
+                return new BoundBadExpression(e.Span);
             var op    = BoundUnaryOperator.Bind(e.Operator.Kind, inExp.Type);
             if (op == null)
             {
@@ -157,6 +159,8 @@ namespace Upsilon.Binder
         {
             var left = BindExpression(e.Left);
             var right = BindExpression(e.Right);
+            if (left.Kind == BoundKind.BoundBadExpression || right.Kind == BoundKind.BoundBadExpression)
+                return new BoundBadExpression(e.Span);
             var op = BoundBinaryOperator.Bind(e.Operator.Kind, left.Type, right.Type);
             if (op == null)
             {
@@ -206,7 +210,7 @@ namespace Upsilon.Binder
             if (expression.Type != Type.Function && expression.Type != Type.Unknown)
             {
                 _diagnostics.LogError($"Unknown function called.", e.Span);
-                return new BoundLiteralExpression(new ScriptNull(), e.Span);
+                return new BoundBadExpression(e.Span);
             }
 
             var parameters = ImmutableArray.CreateBuilder<BoundExpression>();
@@ -378,7 +382,7 @@ namespace Upsilon.Binder
             if (!Scope.TryGetVariable(name, true, out var variable))
             {
                 _diagnostics.LogUnknownVariable(e.Identifier.Span, name);
-                return new BoundLiteralExpression(new ScriptNull(), e.Span);
+                return new BoundBadExpression(e.Span);
             }
             var boundVariable = new BoundVariableSymbol(variable, false, e.Identifier.Span);
             return new BoundVariableExpression(boundVariable, e.Span);
@@ -480,7 +484,7 @@ namespace Upsilon.Binder
                 }
             }
 
-            return new BoundExpressionStatement(new BoundLiteralExpression(new ScriptNull(), e.Span), e.Span);
+            return new BoundExpressionStatement(new BoundBadExpression(e.Span), e.Span);
         }
 
         private BoundStatement BindMultiAssignmentStatement(MultiAssignmentStatementSyntax s)
@@ -642,7 +646,7 @@ namespace Upsilon.Binder
                     else
                     {
                         _diagnostics.LogCannotConvert(Type.Function, variable.Type, e.Span);
-                        return new BoundExpressionStatement(new BoundLiteralExpression(new ScriptNull(), e.Span), e.Span);
+                        return new BoundExpressionStatement(new BoundBadExpression(e.Span), e.Span);
                     }
                 }
             }
@@ -706,7 +710,7 @@ namespace Upsilon.Binder
             if (index.Type != Type.Number && index.Type != Type.String && index.Type != Type.Unknown)
             {
                 _diagnostics.LogInvalidIndexExpression(expression.Type, index.Type, e.Span);
-                return new BoundLiteralExpression(new ScriptNull(), e.Span);
+                return new BoundBadExpression(e.Span);
             }
             switch (expression.Type)
             {
@@ -756,7 +760,7 @@ namespace Upsilon.Binder
                     return new BoundIndexExpression(expression, index, Type.String, e.Span);
                 default:
                     _diagnostics.LogInvalidIndexExpression(expression.Type, index.Type, e.Span);
-                    return new BoundLiteralExpression(new ScriptNull(), e.Span);
+                    return new BoundBadExpression(e.Span);
             }
         }
 
@@ -823,7 +827,7 @@ namespace Upsilon.Binder
                     return new BoundFullStopIndexExpression(expression, index, Type.String, e.Span);
                 default:
                     _diagnostics.LogInvalidIndexExpression(expression.Type, Type.String, e.Span);
-                    return new BoundLiteralExpression(new ScriptNull(), e.Span);
+                    return new BoundBadExpression(e.Span);
             }
         }
 

Upsilon/Binder/BoundExpressions/BoundBadExpression.cs

@@ -0,0 +1,26 @@
+using System.Collections.Generic;
+using Upsilon.BaseTypes;
+using Upsilon.Text;
+
+namespace Upsilon.Binder
+{
+    public class BoundBadExpression : BoundExpression
+    {
+        public BoundBadExpression(TextSpan span) : base(span)
+        {
+        }
+
+        public override BoundKind Kind => BoundKind.BoundBadExpression;
+        public override IEnumerable<BoundNode> GetNodeAtPosition(int linePosition, int characterPosition)
+        {
+            yield break;
+        }
+
+        public override IEnumerable<BoundNode> GetChildren()
+        {
+            yield break;
+        }
+
+        public override Type Type => Type.Nil;
+    }
+}

Upsilon/Binder/BoundKind.cs

@@ -13,6 +13,7 @@ namespace Upsilon.Binder
         BoundTableExpression,
         BoundIndexExpression,
         BoundFunctionExpression,
+        BoundBadExpression,
 
         // Statements
         BoundAssignmentStatement,
@@ -29,6 +30,6 @@ namespace Upsilon.Binder
         BoundNumericForStatement,
         BoundGenericForStatement,
         BoundBreakStatement,
-        BoundWhileStatement
+        BoundWhileStatement,
     }
 }

Upsilon/Evaluator/Evaluator.cs

@@ -254,7 +254,7 @@ namespace Upsilon.Evaluator
                 case BoundKind.BoundFullstopIndexExpression:
                     return EvaluateFullStopIndexExpression((BoundFullStopIndexExpression) e);
                 default:
-                    throw new NotImplementedException();
+                    throw new NotImplementedException(e.Kind.ToString());
             }
         }
 

Ycicle/Program.cs

@@ -38,6 +38,19 @@ namespace Ycicle
                     Console.ResetColor();
                     continue;
                 }
+                script.Bind();
+                if (script.Diagnostics.Errors.Count > 0)
+                {
+                    Console.ForegroundColor = ConsoleColor.Red;
+                    Console.WriteLine("Errors were found during parsing");
+                    foreach (var diagnosticsMessage in script.Diagnostics.Errors)
+                    {
+                        LogMessage(DiagnosticLevel.Error, diagnosticsMessage);
+                    }
+                    Console.ResetColor();
+                    continue;
+                }
+
                 //Console.WriteLine(script.PrettyPrintSyntaxTree());
                 var evaluate = script.Evaluate();