Fix line wrapping with syntax highlighting

renderer.go

@@ -360,8 +360,11 @@ func (r *Renderer) lex(lexer Lexer, input string) {
  s := input
 
  prefix := r.prefixCallback()
- r.renderPrefix(prefix)
+ prefixWidth := istrings.GetWidth(prefix)
+ col := r.col - prefixWidth
  multilinePrefix := r.getMultilinePrefix(prefix)
+ r.renderPrefix(prefix)
+ var lineCharIndex istrings.Width
  for {
  token, ok := lexer.Next()
  if !ok {
@@ -372,15 +375,25 @@ func (r *Renderer) lex(lexer Lexer, input string) {
  s = strings.TrimPrefix(s, text)
 
  var lineBuffer strings.Builder
+
  for _, char := range text {
- lineBuffer.WriteRune(char)
- if char != '\n' {
+ if lineCharIndex >= col || char == '\n' {
+ if char != '\n' {
+ lineBuffer.WriteByte('\n')
+ }
+ r.writeString(lineBuffer.String(), token.Color())
+ r.renderPrefix(multilinePrefix)
+ lineCharIndex = 0
+ lineBuffer.Reset()
+ if char != '\n' {
+ lineBuffer.WriteRune(char)
+ lineCharIndex += istrings.GetRuneWidth(char)
+ }
  continue
  }
 
- r.writeString(lineBuffer.String(), token.Color())
- r.renderPrefix(multilinePrefix)
- lineBuffer.Reset()
+ lineBuffer.WriteRune(char)
+ lineCharIndex += istrings.GetRuneWidth(char)
  }
  r.writeString(lineBuffer.String(), token.Color())
  }
@@ -395,8 +408,11 @@ func (r *Renderer) BreakLine(buffer *Buffer, lexer Lexer) {
  cursor.X += prefixWidth
  r.clear(cursor)
 
- text := buffer.Document().Text + "\n"
+ text := buffer.Document().Text
  r.renderText(lexer, text)
+ if _, err := r.out.WriteString("\n"); err != nil {
+ panic(err)
+ }
 
  r.out.SetColor(DefaultColor, DefaultColor, false)