spanFor method

@override SourceMapSpan? spanFor(int line, int column, { Map<String, SourceFile>? files, String? uri, })

Returns the span associated with line and column.

uri is the optional location of the output file to find the span for to disambiguate cases where a mapping may have different mappings for different output files.

Implementation

@override
SourceMapSpan? spanFor(int line, int column,
    {Map<String, SourceFile>? files, String? uri}) {
  var entry = _findColumn(line, column, _findLine(line));
  if (entry == null) return null;

  var sourceUrlId = entry.sourceUrlId;
  if (sourceUrlId == null) return null;

  var url = urls[sourceUrlId];
  if (sourceRoot != null) {
    url = '$sourceRoot$url';
  }

  var sourceNameId = entry.sourceNameId;
  var file = files?[url];
  if (file != null) {
    var start = file.getOffset(entry.sourceLine!, entry.sourceColumn);
    if (sourceNameId != null) {
      var text = names[sourceNameId];
      return SourceMapFileSpan(file.span(start, start + text.length),
          isIdentifier: true);
    } else {
      return SourceMapFileSpan(file.location(start).pointSpan());
    }
  } else {
    var start = SourceLocation(0,
        sourceUrl: _mapUrl?.resolve(url) ?? url,
        line: entry.sourceLine,
        column: entry.sourceColumn);

    // Offset and other context is not available.
    if (sourceNameId != null) {
      return SourceMapSpan.identifier(start, names[sourceNameId]);
    } else {
      return SourceMapSpan(start, start, '');
    }
  }
}