Index: string_scanner/lib/src/string_scanner.dart |
diff --git a/string_scanner/lib/src/string_scanner.dart b/string_scanner/lib/src/string_scanner.dart |
deleted file mode 100644 |
index d9c1c2fd3c109c692671508a2e514a6bd5e9ec16..0000000000000000000000000000000000000000 |
--- a/string_scanner/lib/src/string_scanner.dart |
+++ /dev/null |
@@ -1,176 +0,0 @@ |
-// Copyright (c) 2014, 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.string_scanner; |
- |
-import 'package:source_span/source_span.dart'; |
- |
-import 'exception.dart'; |
-import 'utils.dart'; |
- |
-/// When compiled to JS, forward slashes are always escaped in [RegExp.pattern]. |
-/// |
-/// See issue 17998. |
-final _slashAutoEscape = new RegExp("/").pattern == "\\/"; |
- |
-/// A class that scans through a string using [Pattern]s. |
-class StringScanner { |
- /// The URL of the source of the string being scanned. |
- /// |
- /// This is used for error reporting. It may be `null`, indicating that the |
- /// source URL is unknown or unavailable. |
- final Uri sourceUrl; |
- |
- /// The string being scanned through. |
- final String string; |
- |
- /// The current position of the scanner in the string, in characters. |
- int get position => _position; |
- set position(int position) { |
- if (position < 0 || position > string.length) { |
- throw new ArgumentError("Invalid position $position"); |
- } |
- |
- _position = position; |
- } |
- int _position = 0; |
- |
- /// The data about the previous match made by the scanner. |
- /// |
- /// If the last match failed, this will be `null`. |
- Match get lastMatch => _lastMatch; |
- Match _lastMatch; |
- |
- /// The portion of the string that hasn't yet been scanned. |
- String get rest => string.substring(position); |
- |
- /// Whether the scanner has completely consumed [string]. |
- bool get isDone => position == string.length; |
- |
- /// Creates a new [StringScanner] that starts scanning from [position]. |
- /// |
- /// [position] defaults to 0, the beginning of the string. [sourceUrl] is the |
- /// URL of the source of the string being scanned, if available. It can be |
- /// a [String], a [Uri], or `null`. |
- StringScanner(this.string, {sourceUrl, int position}) |
- : sourceUrl = sourceUrl is String ? Uri.parse(sourceUrl) : sourceUrl { |
- if (position != null) this.position = position; |
- } |
- |
- /// Consumes a single character and returns its character code. |
- /// |
- /// This throws a [FormatException] if the string has been fully consumed. It |
- /// doesn't affect [lastMatch]. |
- int readChar() { |
- if (isDone) _fail("more input"); |
- return string.codeUnitAt(_position++); |
- } |
- |
- /// Returns the character code of the character [offset] away from [position]. |
- /// |
- /// [offset] defaults to zero, and may be negative to inspect already-consumed |
- /// characters. |
- /// |
- /// This returns `null` if [offset] points outside the string. It doesn't |
- /// affect [lastMatch]. |
- int peekChar([int offset]) { |
- if (offset == null) offset = 0; |
- var index = position + offset; |
- if (index < 0 || index >= string.length) return null; |
- return string.codeUnitAt(index); |
- } |
- |
- /// If [pattern] matches at the current position of the string, scans forward |
- /// until the end of the match. |
- /// |
- /// Returns whether or not [pattern] matched. |
- bool scan(Pattern pattern) { |
- var success = matches(pattern); |
- if (success) _position = _lastMatch.end; |
- return success; |
- } |
- |
- /// If [pattern] matches at the current position of the string, scans forward |
- /// until the end of the match. |
- /// |
- /// If [pattern] did not match, throws a [FormatException] describing the |
- /// position of the failure. [name] is used in this error as the expected name |
- /// of the pattern being matched; if it's `null`, the pattern itself is used |
- /// instead. |
- void expect(Pattern pattern, {String name}) { |
- if (scan(pattern)) return; |
- |
- if (name == null) { |
- if (pattern is RegExp) { |
- var source = pattern.pattern; |
- if (!_slashAutoEscape) source = source.replaceAll("/", "\\/"); |
- name = "/$source/"; |
- } else { |
- name = |
- pattern.toString().replaceAll("\\", "\\\\").replaceAll('"', '\\"'); |
- name = '"$name"'; |
- } |
- } |
- _fail(name); |
- } |
- |
- /// If the string has not been fully consumed, this throws a |
- /// [FormatException]. |
- void expectDone() { |
- if (isDone) return; |
- _fail("no more input"); |
- } |
- |
- /// Returns whether or not [pattern] matches at the current position of the |
- /// string. |
- /// |
- /// This doesn't move the scan pointer forward. |
- bool matches(Pattern pattern) { |
- _lastMatch = pattern.matchAsPrefix(string, position); |
- return _lastMatch != null; |
- } |
- |
- /// Returns the substring of [string] between [start] and [end]. |
- /// |
- /// Unlike [String.substring], [end] defaults to [position] rather than the |
- /// end of the string. |
- String substring(int start, [int end]) { |
- if (end == null) end = position; |
- return string.substring(start, end); |
- } |
- |
- /// Throws a [FormatException] with [message] as well as a detailed |
- /// description of the location of the error in the string. |
- /// |
- /// [match] is the match information for the span of the string with which the |
- /// error is associated. This should be a match returned by this scanner's |
- /// [lastMatch] property. By default, the error is associated with the last |
- /// match. |
- /// |
- /// If [position] and/or [length] are passed, they are used as the error span |
- /// instead. If only [length] is passed, [position] defaults to the current |
- /// position; if only [position] is passed, [length] defaults to 1. |
- /// |
- /// It's an error to pass [match] at the same time as [position] or [length]. |
- void error(String message, {Match match, int position, int length}) { |
- validateErrorArgs(string, match, position, length); |
- |
- if (match == null && position == null && length == null) match = lastMatch; |
- if (position == null) { |
- position = match == null ? this.position : match.start; |
- } |
- if (length == null) length = match == null ? 1 : match.end - match.start; |
- |
- var sourceFile = new SourceFile(string, url: sourceUrl); |
- var span = sourceFile.span(position, position + length); |
- throw new StringScannerException(message, span, string); |
- } |
- |
- // TODO(nweiz): Make this handle long lines more gracefully. |
- /// Throws a [FormatException] describing that [name] is expected at the |
- /// current position in the string. |
- void _fail(String name) { |
- error("expected $name.", position: this.position, length: 0); |
- } |
-} |