Merge pull request #581 from kevmoo/polymer

lib/src/refactor.dart

-// Copyright (c) 2012, 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.
-
-/**
- * Tools to help implement refactoring like transformations to Dart code.
- *
- * [TextEditTransaction] supports making a series of changes to a text buffer.
- * [guessIndent] helps to guess the appropriate indentiation for the new code.
- */
-library refactor;
-
-import 'code_printer.dart';
-import 'package:source_maps/span.dart';
-
-const $CR = 13;
-const $LF = 10;
-const $TAB = 9;
-const $SPACE = 32;
-
-/**
- * Editable text transaction. Applies a series of edits using original location
- * information, and composes them into the edited string.
- */
-class TextEditTransaction {
-  final SourceFile file;
-  final String original;
-  final _edits = <_TextEdit>[];
-
-  TextEditTransaction(this.original, this.file);
-
-  bool get hasEdits => _edits.length > 0;
-
-  /**
-   * Edit the original text, replacing text on the range [begin] and [end]
-   * with the [replacement]. [replacement] can be either a string or a
-   * [CodePrinter].
-   */
-  void edit(int begin, int end, replacement) {
-    _edits.add(new _TextEdit(begin, end, replacement));
-  }
-
-  /** Create a source map [Location] for [offset]. */
-  Location _loc(int offset) =>
-      file != null ? file.location(offset) : null;
-
-  /**
-   * Applies all pending [edit]s and returns the rewritten string.
-   * If no edits were made, returns the [original] string.
-   * Throws [UnsupportedError] if the edits were overlapping.
-   */
-  CodePrinter commit() {
-    var printer = new CodePrinter(0);
-    if (_edits.length == 0) {
-      printer.add(original, location: _loc(0), isOriginal: true);
-      return printer;
-    }
-
-    // Sort edits by start location.
-    _edits.sort();
-
-    int consumed = 0;
-    for (var edit in _edits) {
-      if (consumed > edit.begin) {
-        var sb = new StringBuffer();
-        sb..write(file.location(edit.begin).formatString)
-            ..write(': overlapping edits. Insert at offset ')
-            ..write(edit.begin)
-            ..write(' but have consumed ')
-            ..write(consumed)
-            ..write(' input characters. List of edits:');
-        for (var e in _edits) sb..write('\n    ')..write(e);
-        throw new UnsupportedError(sb.toString());
-      }
-
-      // Add characters from the original string between this edit and the last
-      // one, if any.
-      var betweenEdits = original.substring(consumed, edit.begin);
-      printer..add(betweenEdits, location: _loc(consumed), isOriginal: true)
-             ..add(edit.replace, location: _loc(edit.begin));
-      consumed = edit.end;
-    }
-
-    // Add any text from the end of the original string that was not replaced.
-    printer.add(original.substring(consumed),
-        location: _loc(consumed), isOriginal: true);
-    return printer;
-  }
-}
-
-class _TextEdit implements Comparable<_TextEdit> {
-  final int begin;
-  final int end;
-
-  /** The replacement used by the edit, can be a string or a [CodePrinter]. */
-  final replace;
-
-  _TextEdit(this.begin, this.end, this.replace);
-
-  int get length => end - begin;
-
-  String toString() => '(Edit @ $begin,$end: "$replace")';
-
-  int compareTo(_TextEdit other) {
-    int diff = begin - other.begin;
-    if (diff != 0) return diff;
-    return end - other.end;
-  }
-}
-
-/**
- * Finds and returns all whitespace characters at the start of the current line.
- */
-String guessIndent(String code, int charOffset) {
-  // Find the beginning of the line
-  int lineStart = 0;
-  for (int i = charOffset - 1; i >= 0; i--) {
-    var c = code.codeUnitAt(i);
-    if (c == $LF || c == $CR) {
-      lineStart = i + 1;
-      break;
-    }
-  }
-
-  // Grab all the whitespace
-  int whitespaceEnd = code.length;
-  for (int i = lineStart; i < code.length; i++) {
-    var c = code.codeUnitAt(i);
-    if (c != $SPACE && c != $TAB) {
-      whitespaceEnd = i;
-      break;
-    }
-  }
-
-  return code.substring(lineStart, whitespaceEnd);
-}