Method lookup

src/source_map_support.js:62–74

(offset)

  }

  lookup(offset) {
    var normalized = this.normalizeOffset(offset);
    var info = this.mapping[normalized];
    if (!info) {
      return null;
    }
    return {
      file: this.sources[info.source],
      line: info.line,
      column: info.column,
      name: this.names[info.name],
    };
  }

  normalizeOffset(offset) {
    var lo = 0;