Method TranslatePosition

pkg/lsp/translator.go:52–202

TranslatePosition translates a single position between Dingo and Go files. LSP uses character offsets (0-indexed), where each character (including tabs) counts as 1. This is NOT visual columns - tabs are 1 character, not 4 visual columns.

(
	uri protocol.DocumentURI,
	pos protocol.Position,
	dir Direction,
)

// LSP uses character offsets (0-indexed), where each character (including tabs) counts as 1.
// This is NOT visual columns - tabs are 1 character, not 4 visual columns.
func (t *Translator) TranslatePosition(
	uri protocol.DocumentURI,
	pos protocol.Position,
	dir Direction,
) (protocol.DocumentURI, protocol.Position, error) {
	dirName := "DingoToGo"
	if dir == GoToDingo {
		dirName = "GoToDingo"
	}
	log.Printf("[LSP Translator] TranslatePosition START: direction=%s, uri=%s, line=%d, char=%d",
		dirName, uri.Filename(), pos.Line, pos.Character)

	// Convert LSP position (0-based) to 1-based for dmap
	line := int(pos.Line) + 1
	col := int(pos.Character) + 1 // LSP character offset is 0-indexed, dmap uses 1-indexed

	// Determine file paths using config-aware path calculation
	var goPath string
	if dir == DingoToGo {
		goPath = dingoToGoPathWithConfig(uri.Filename(), t.dingoConfig)
	} else {
		goPath = uri.Filename()
	}

	// Load source map reader
	reader, err := t.cache.Get(goPath)
	if err != nil {
		// CRITICAL FIX C6: Still translate URI even with 1:1 positions
		// Bug was: returning .dingo URI to gopls when source map missing
		if dir == DingoToGo {
			// Must return .go URI, not .dingo URI
			goURI := lspuri.File(goPath)
			return goURI, pos, fmt.Errorf("source map not found: %s (file not transpiled)", goPath)
		}
		// CRITICAL FIX: For Go->Dingo without map, return location unchanged
		// This handles standard library and external package definitions
		// No source map = not a transpiled file, so return the .go location as-is
		log.Printf("[LSP Translator] No source map for %s, returning location unchanged (likely stdlib/external package)", goPath)
		return uri, pos, nil
	}

	// Translate position using binary .dmap reader
	var newLine, newCol int
	var newURI protocol.DocumentURI

	if dir == DingoToGo {
		// Use DingoLineToGoLine which handles both:
		// - Transformed lines (returns GoLineStart where actual code is)
		// - Untransformed lines (uses line shift calculation)
		newLine = reader.DingoLineToGoLine(line)

		// Apply column translation for transformed lines (error propagation, etc.)
		// This adjusts for LHS changes: "userID := func()?" -> "tmp, err := func()"
		var colFound bool
		newCol, colFound = reader.TranslateDingoColumn(line, col)
		if colFound {
			log.Printf("[LSP Translator] DingoToGo: column translated %d -> %d", col, newCol)
		} else {