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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 /// Tools to help implement refactoring like transformations to Dart code. | |
6 /// | |
7 /// [TextEditTransaction] supports making a series of changes to a text buffer. | |
8 /// [guessIndent] helps to guess the appropriate indentiation for the new code. | |
9 library source_maps.refactor; | |
10 | |
11 import 'span.dart'; | |
12 import 'printer.dart'; | |
13 | |
14 /// Editable text transaction. | |
15 /// | |
16 /// Applies a series of edits using original location | |
17 /// information, and composes them into the edited string. | |
18 class TextEditTransaction { | |
19 final SourceFile file; | |
20 final String original; | |
21 final _edits = <_TextEdit>[]; | |
22 | |
23 TextEditTransaction(this.original, this.file); | |
24 | |
25 bool get hasEdits => _edits.length > 0; | |
26 | |
27 /// Edit the original text, replacing text on the range [begin] and [end] | |
28 /// with the [replacement]. [replacement] can be either a string or a | |
29 /// [NestedPrinter]. | |
30 void edit(int begin, int end, replacement) { | |
31 _edits.add(new _TextEdit(begin, end, replacement)); | |
32 } | |
33 | |
34 /// Create a source map [Location] for [offset]. | |
35 Location _loc(int offset) => | |
36 file != null ? file.location(offset) : null; | |
37 | |
38 /// Applies all pending [edit]s and returns a [NestedPrinter] containing the | |
39 /// rewritten string and source map information. [filename] is given to the | |
40 /// underlying printer to indicate the name of the generated file that will | |
41 /// contains the source map information. | |
42 /// | |
43 /// Throws [UnsupportedError] if the edits were overlapping. If no edits were | |
44 /// made, the printer simply contains the original string. | |
45 NestedPrinter commit() { | |
46 var printer = new NestedPrinter(); | |
47 if (_edits.length == 0) { | |
48 return printer..add(original, location: _loc(0), isOriginal: true); | |
49 } | |
50 | |
51 // Sort edits by start location. | |
52 _edits.sort(); | |
53 | |
54 int consumed = 0; | |
55 for (var edit in _edits) { | |
56 if (consumed > edit.begin) { | |
57 var sb = new StringBuffer(); | |
58 sb..write(file.location(edit.begin).formatString) | |
59 ..write(': overlapping edits. Insert at offset ') | |
60 ..write(edit.begin) | |
61 ..write(' but have consumed ') | |
62 ..write(consumed) | |
63 ..write(' input characters. List of edits:'); | |
64 for (var e in _edits) sb..write('\n ')..write(e); | |
65 throw new UnsupportedError(sb.toString()); | |
66 } | |
67 | |
68 // Add characters from the original string between this edit and the last | |
69 // one, if any. | |
70 var betweenEdits = original.substring(consumed, edit.begin); | |
71 printer..add(betweenEdits, location: _loc(consumed), isOriginal: true) | |
72 ..add(edit.replace, location: _loc(edit.begin)); | |
73 consumed = edit.end; | |
74 } | |
75 | |
76 // Add any text from the end of the original string that was not replaced. | |
77 printer.add(original.substring(consumed), | |
78 location: _loc(consumed), isOriginal: true); | |
79 return printer; | |
80 } | |
81 } | |
82 | |
83 class _TextEdit implements Comparable<_TextEdit> { | |
84 final int begin; | |
85 final int end; | |
86 | |
87 /// The replacement used by the edit, can be a string or a [NestedPrinter]. | |
88 final replace; | |
89 | |
90 _TextEdit(this.begin, this.end, this.replace); | |
91 | |
92 int get length => end - begin; | |
93 | |
94 String toString() => '(Edit @ $begin,$end: "$replace")'; | |
95 | |
96 int compareTo(_TextEdit other) { | |
97 int diff = begin - other.begin; | |
98 if (diff != 0) return diff; | |
99 return end - other.end; | |
100 } | |
101 } | |
102 | |
103 /** | |
Jennifer Messerly
2013/08/09 22:14:47
triple slash?
Siggi Cherem (dart-lang)
2013/08/09 22:19:51
I had a feeling I was going to miss one... thanks!
| |
104 * Finds and returns all whitespace characters at the start of the current line. | |
105 */ | |
106 String guessIndent(String code, int charOffset) { | |
107 // Find the beginning of the line | |
108 int lineStart = 0; | |
109 for (int i = charOffset - 1; i >= 0; i--) { | |
110 var c = code.codeUnitAt(i); | |
111 if (c == _LF || c == _CR) { | |
112 lineStart = i + 1; | |
113 break; | |
114 } | |
115 } | |
116 | |
117 // Grab all the whitespace | |
118 int whitespaceEnd = code.length; | |
119 for (int i = lineStart; i < code.length; i++) { | |
120 var c = code.codeUnitAt(i); | |
121 if (c != _SPACE && c != _TAB) { | |
122 whitespaceEnd = i; | |
123 break; | |
124 } | |
125 } | |
126 | |
127 return code.substring(lineStart, whitespaceEnd); | |
128 } | |
129 | |
130 const int _CR = 13; | |
131 const int _LF = 10; | |
132 const int _TAB = 9; | |
133 const int _SPACE = 32; | |
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