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1 : // Copyright (c) 2013, the Dart project authors. Please see the AUTHORS file
2 : // for details. All rights reserved. Use of this source code is governed by a
3 : // BSD-style license that can be found in the LICENSE file.
4 :
5 : /// Contains a builder object useful for creating source maps programatically.
6 : library source_maps.builder;
7 :
8 : // TODO(sigmund): add a builder for multi-section mappings.
9 :
10 : import 'dart:convert';
11 :
12 : import 'package:source_span/source_span.dart';
13 :
14 : import 'parser.dart';
15 : import 'src/source_map_span.dart';
16 :
17 : /// Builds a source map given a set of mappings.
18 : class SourceMapBuilder {
19 :
20 : final List<Entry> _entries = <Entry>[];
21 :
22 : /// Adds an entry mapping the [targetOffset] to [source].
23 : void addFromOffset(SourceLocation source, SourceFile targetFile,
24 : int targetOffset, String identifier) {
25 : if (targetFile == null) {
26 0 : throw new ArgumentError('targetFile cannot be null');
27 : }
28 0 : _entries.add(
29 0 : new Entry(source, targetFile.location(targetOffset), identifier));
30 : }
31 :
32 : /// Adds an entry mapping [target] to [source].
33 : ///
34 : /// If [isIdentifier] is true or if [target] is a [SourceMapSpan] with
35 : /// `isIdentifier` set to true, this entry is considered to represent an
36 : /// identifier whose value will be stored in the source map. [isIdenfier]
37 : /// takes precedence over [target]'s `isIdentifier` value.
38 : void addSpan(SourceSpan source, SourceSpan target, {bool isIdentifier}) {
39 : if (isIdentifier == null) {
40 0 : isIdentifier = source is SourceMapSpan ? source.isIdentifier : false;
41 : }
42 :
43 0 : var name = isIdentifier ? source.text : null;
44 0 : _entries.add(new Entry(source.start, target.start, name));
45 : }
46 :
47 : /// Adds an entry mapping [target] to [source].
48 : void addLocation(SourceLocation source, SourceLocation target,
49 : String identifier) {
50 0 : _entries.add(new Entry(source, target, identifier));
51 : }
52 :
53 : /// Encodes all mappings added to this builder as a json map.
54 : Map build(String fileUrl) {
55 0 : return new SingleMapping.fromEntries(this._entries, fileUrl).toJson();
56 : }
57 :
58 : /// Encodes all mappings added to this builder as a json string.
59 0 : String toJson(String fileUrl) => JSON.encode(build(fileUrl));
60 : }
61 :
62 : /// An entry in the source map builder.
63 : class Entry implements Comparable<Entry> {
64 : /// Span denoting the original location in the input source file
65 : final SourceLocation source;
66 :
67 : /// Span indicating the corresponding location in the target file.
68 : final SourceLocation target;
69 :
70 : /// An identifier name, when this location is the start of an identifier.
71 : final String identifierName;
72 :
73 : /// Creates a new [Entry] mapping [target] to [source].
74 0 : Entry(this.source, this.target, this.identifierName);
75 :
76 : /// Implements [Comparable] to ensure that entries are ordered by their
77 : /// location in the target file. We sort primarily by the target offset
78 : /// because source map files are encoded by printing each mapping in order as
79 : /// they appear in the target file.
80 : int compareTo(Entry other) {
81 0 : int res = target.compareTo(other.target);
82 0 : if (res != 0) return res;
83 0 : res = source.sourceUrl.toString().compareTo(
84 0 : other.source.sourceUrl.toString());
85 0 : if (res != 0) return res;
86 0 : return source.compareTo(other.source);
87 : }
88 : }
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