blob: cd30ccb94941fd4b2ec57872e3be7a8e3daef716 [file] [log] [blame]
// Copyright (c) 2013, the Dart project authors. Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.
/// Contains a builder object useful for creating source maps programatically.
library source_maps.builder;
// TODO(sigmund): add a builder for multi-section mappings.
import 'dart:convert';
import 'parser.dart';
import 'span.dart';
/// Builds a source map given a set of mappings.
class SourceMapBuilder {
final List<Entry> _entries = <Entry>[];
/// Adds an entry mapping the [targetOffset] to [source].
void addFromOffset(Location source,
SourceFile targetFile, int targetOffset, String identifier) {
if (targetFile == null) {
throw new ArgumentError('targetFile cannot be null');
_entries.add(new Entry(source,
new FileLocation(targetFile, targetOffset), identifier));
/// Adds an entry mapping [target] to [source].
void addSpan(Span source, Span target) {
var name = source.isIdentifier ? source.text : null;
_entries.add(new Entry(source.start, target.start, name));
void addLocation(Location source, Location target, String identifier) {
_entries.add(new Entry(source, target, identifier));
/// Encodes all mappings added to this builder as a json map.
Map build(String fileUrl) {
return new SingleMapping.fromEntries(this._entries, fileUrl).toJson();
/// Encodes all mappings added to this builder as a json string.
String toJson(String fileUrl) => JSON.encode(build(fileUrl));
/// An entry in the source map builder.
class Entry implements Comparable {
/// Span denoting the original location in the input source file
final Location source;
/// Span indicating the corresponding location in the target file.
final Location target;
/// An identifier name, when this location is the start of an identifier.
final String identifierName;
Entry(this.source,, this.identifierName);
/// Implements [Comparable] to ensure that entries are ordered by their
/// location in the target file. We sort primarily by the target offset
/// because source map files are encoded by printing each mapping in order as
/// they appear in the target file.
int compareTo(Entry other) {
int res = target.compareTo(;
if (res != 0) return res;
res = source.sourceUrl.compareTo(other.source.sourceUrl);
if (res != 0) return res;
return source.compareTo(other.source);