Fix diagnostic print

compiler/NubLang/Diagnostics/Diagnostic.cs

@@ -81,8 +81,6 @@ public class Diagnostic
     }
 
     public string FormatANSI()
-    {
-        try
     {
         var sb = new StringBuilder();
 
@@ -107,6 +105,9 @@ public class Diagnostic
             sb.AppendLine();
             var text = File.ReadAllText(Span.Value.FilePath);
 
+            var tokenizer = new Tokenizer(Span.Value.FilePath, text);
+            tokenizer.Tokenize();
+
             var lines = text.Split('\n');
 
             var startLine = Span.Value.Start.Line;
@@ -118,7 +119,16 @@ public class Diagnostic
             var contextEndLine = Math.Min(lines.Length, endLine + CONTEXT_LINES);
 
             var numberPadding = contextEndLine.ToString().Length;
-                var codePadding = lines.Skip(contextStartLine - 1).Take(contextEndLine - contextStartLine + 1).Max(x => x.Length);
+
+            var codePadding = 0;
+            for (var i = contextStartLine - 1; i < contextEndLine && i < lines.Length; i++)
+            {
+                var lineLength = lines[i].Length;
+                if (lineLength > codePadding)
+                {
+                    codePadding = lineLength;
+                }
+            }
 
             sb.Append('╭');
             sb.Append(new string('─', numberPadding + 2));
@@ -127,9 +137,6 @@ public class Diagnostic
             sb.Append('╮');
             sb.AppendLine();
 
-                var tokenizer = new Tokenizer(Span.Value.FilePath, text);
-                tokenizer.Tokenize();
-
             for (var i = contextStartLine; i <= contextEndLine; i++)
             {
                 var line = lines[i - 1];
@@ -138,6 +145,7 @@ public class Diagnostic
                 sb.Append(i.ToString().PadRight(numberPadding));
                 sb.Append(" │ ");
                 sb.Append(ApplySyntaxHighlighting(line.PadRight(codePadding), i, tokenizer.Tokens));
+                // sb.Append(line.PadRight(codePadding));
                 sb.Append(" │");
                 sb.AppendLine();
 
@@ -148,12 +156,12 @@ public class Diagnostic
 
                     if (i == startLine)
                     {
-                            markerStartColumn = Math.Min(Span.Value.Start.Column, 1);
+                        markerStartColumn = Span.Value.Start.Column;
                     }
 
                     if (i == endLine)
                     {
-                            markerEndColumn = Math.Min(Span.Value.End.Column, line.Length);
+                        markerEndColumn = Span.Value.End.Column;
                     }
 
                     var markerLength = markerEndColumn - markerStartColumn;
@@ -172,7 +180,7 @@ public class Diagnostic
                     sb.Append(" │ ");
                     sb.Append(new string(' ', markerStartColumn - 1));
                     sb.Append(ConsoleColors.Colorize(marker, markerColor));
-                        sb.Append(new string(' ', codePadding - markerEndColumn + 1));
+                    sb.Append(new string(' ', codePadding - (markerStartColumn - 1) - markerLength));
                     sb.Append(" │");
                     sb.AppendLine();
                 }
@@ -193,11 +201,6 @@ public class Diagnostic
 
         return sb.ToString();
     }
-        catch (Exception)
-        {
-            return ConsoleColors.Colorize("Failed to generate error message", ConsoleColors.Red);
-        }
-    }
 
     private static string ApplySyntaxHighlighting(string line, int lineNumber, List<Token> tokens)
     {
@@ -219,25 +222,34 @@ public class Diagnostic
             var tokenStart = token.Span.Start.Column;
             var tokenEnd = token.Span.End.Column;
 
-            if (tokenStart > currentColumn)
+            if (tokenStart > currentColumn && currentColumn - 1 < line.Length)
             {
-                var beforeToken = line.Substring(currentColumn - 1, tokenStart - currentColumn);
+                var beforeLength = Math.Min(tokenStart - currentColumn, line.Length - (currentColumn - 1));
+                if (beforeLength > 0)
+                {
+                    var beforeToken = line.Substring(currentColumn - 1, beforeLength);
                     sb.Append(beforeToken);
                 }
+            }
 
             var tokenLength = tokenEnd - tokenStart;
-            if (tokenStart - 1 + tokenLength <= line.Length)
+            if (tokenStart >= 1 && tokenStart - 1 < line.Length && tokenLength > 0)
             {
-                var tokenText = line.Substring(tokenStart - 1, tokenLength);
+                var availableLength = line.Length - (tokenStart - 1);
+                var actualLength = Math.Min(tokenLength, availableLength);
 
+                if (actualLength > 0)
+                {
+                    var tokenText = line.Substring(tokenStart - 1, actualLength);
                     var coloredToken = ColorizeToken(token, tokenText);
                     sb.Append(coloredToken);
                 }
+            }
 
             currentColumn = tokenEnd;
         }
 
-        if (currentColumn <= line.Length)
+        if (currentColumn - 1 < line.Length)
         {
             var remaining = line[(currentColumn - 1)..];
             sb.Append(remaining);

compiler/NubLang/Syntax/Tokenizer.cs

@@ -90,23 +90,23 @@ public sealed class Tokenizer
         {
             try
             {
-                // Skip whitespace and increment line counter if newline
                 var current = Peek()!.Value;
                 if (char.IsWhiteSpace(current))
                 {
                     if (current is '\n')
                     {
                         _line += 1;
-                        _column = 1;
+                        // note(nub31): Next increments the column, so 0 is correct here
+                        _column = 0;
                     }
 
                     Next();
                     continue;
                 }
 
-                // Skip single line comments but keep newline so next iteration increments the line counter
                 if (current == '/' && Peek(1) == '/')
                 {
+                    // note(nub31): Keep newline so next iteration increments the line counter
                     while (Peek() is not '\n')
                     {
                         Next();

examples/raylib/main.nub

@@ -4,7 +4,7 @@ module "main"
 
 extern "main" func main(args: []cstring): i64
 {
-    raylib::SetConfigFlags(4 | 64)
+    raylib: :SetConfigFlags(4 | 64)
 
     raylib::InitWindow(1600, 900, "Hi from nub-lang")
     defer raylib::CloseWindow()