Index: mojo/public/dart/third_party/string_scanner/lib/src/eager_span_scanner.dart |
diff --git a/mojo/public/dart/third_party/string_scanner/lib/src/eager_span_scanner.dart b/mojo/public/dart/third_party/string_scanner/lib/src/eager_span_scanner.dart |
new file mode 100644 |
index 0000000000000000000000000000000000000000..3fae5cca7cfdefa1017b8b6298d1680df1f8f34e |
--- /dev/null |
+++ b/mojo/public/dart/third_party/string_scanner/lib/src/eager_span_scanner.dart |
@@ -0,0 +1,115 @@ |
+// Copyright (c) 2015, 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. |
+ |
+library string_scanner.eager_span_scanner; |
+ |
+import 'package:charcode/ascii.dart'; |
+ |
+import 'line_scanner.dart'; |
+import 'span_scanner.dart'; |
+ |
+// TODO(nweiz): Currently this duplicates code in line_scanner.dart. Once |
+// sdk#23770 is fully complete, we should move the shared code into a mixin. |
+ |
+/// A regular expression matching newlines across platforms. |
+final _newlineRegExp = new RegExp(r"\r\n?|\n"); |
+ |
+/// A [SpanScanner] that tracks the line and column eagerly, like [LineScanner]. |
+class EagerSpanScanner extends SpanScanner { |
+ int get line => _line; |
+ int _line = 0; |
+ |
+ int get column => _column; |
+ int _column = 0; |
+ |
+ LineScannerState get state => |
+ new _EagerSpanScannerState(this, position, line, column); |
+ |
+ bool get _betweenCRLF => peekChar(-1) == $cr && peekChar() == $lf; |
+ |
+ set state(LineScannerState state) { |
+ if (state is! _EagerSpanScannerState || |
+ !identical((state as _EagerSpanScannerState)._scanner, this)) { |
+ throw new ArgumentError("The given LineScannerState was not returned by " |
+ "this LineScanner."); |
+ } |
+ |
+ super.position = state.position; |
+ _line = state.line; |
+ _column = state.column; |
+ } |
+ |
+ set position(int newPosition) { |
+ var oldPosition = position; |
+ super.position = newPosition; |
+ |
+ if (newPosition > oldPosition) { |
+ var newlines = _newlinesIn(string.substring(oldPosition, newPosition)); |
+ _line += newlines.length; |
+ if (newlines.isEmpty) { |
+ _column += newPosition - oldPosition; |
+ } else { |
+ _column = newPosition - newlines.last.end; |
+ } |
+ } else { |
+ var newlines = _newlinesIn(string.substring(newPosition, oldPosition)); |
+ if (_betweenCRLF) newlines.removeLast(); |
+ |
+ _line -= newlines.length; |
+ if (newlines.isEmpty) { |
+ _column -= oldPosition - newPosition; |
+ } else { |
+ _column = newPosition - |
+ string.lastIndexOf(_newlineRegExp, newPosition) - 1; |
+ } |
+ } |
+ } |
+ |
+ EagerSpanScanner(String string, {sourceUrl, int position}) |
+ : super(string, sourceUrl: sourceUrl, position: position); |
+ |
+ int readChar() { |
+ var char = super.readChar(); |
+ if (char == $lf || (char == $cr && peekChar() != $lf)) { |
+ _line += 1; |
+ _column = 0; |
+ } else { |
+ _column += 1; |
+ } |
+ return char; |
+ } |
+ |
+ bool scan(Pattern pattern) { |
+ if (!super.scan(pattern)) return false; |
+ |
+ var newlines = _newlinesIn(lastMatch[0]); |
+ _line += newlines.length; |
+ if (newlines.isEmpty) { |
+ _column += lastMatch[0].length; |
+ } else { |
+ _column = lastMatch[0].length - newlines.last.end; |
+ } |
+ |
+ return true; |
+ } |
+ |
+ /// Returns a list of [Match]es describing all the newlines in [text], which |
+ /// is assumed to end at [position]. |
+ List<Match> _newlinesIn(String text) { |
+ var newlines = _newlineRegExp.allMatches(text).toList(); |
+ if (_betweenCRLF) newlines.removeLast(); |
+ return newlines; |
+ } |
+} |
+ |
+/// A class representing the state of an [EagerSpanScanner]. |
+class _EagerSpanScannerState implements LineScannerState { |
+ final EagerSpanScanner _scanner; |
+ final int position; |
+ final int line; |
+ final int column; |
+ |
+ _EagerSpanScannerState(this._scanner, this.position, this.line, this.column); |
+} |
+ |