1#!/usr/bin/env python
2#
3# Copyright 2007 The Closure Linter Authors. All Rights Reserved.
4#
5# Licensed under the Apache License, Version 2.0 (the "License");
6# you may not use this file except in compliance with the License.
7# You may obtain a copy of the License at
8#
9#      http://www.apache.org/licenses/LICENSE-2.0
10#
11# Unless required by applicable law or agreed to in writing, software
12# distributed under the License is distributed on an "AS-IS" BASIS,
13# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14# See the License for the specific language governing permissions and
15# limitations under the License.
16
17"""Regular expression based JavaScript matcher classes."""
18
19__author__ = ('robbyw@google.com (Robert Walker)',
20              'ajp@google.com (Andy Perelson)')
21
22from closure_linter.common import position
23from closure_linter.common import tokens
24
25# Shorthand
26Token = tokens.Token
27Position = position.Position
28
29
30class Matcher(object):
31  """A token matcher.
32
33  Specifies a pattern to match, the type of token it represents, what mode the
34  token changes to, and what mode the token applies to.
35
36  Modes allow more advanced grammars to be incorporated, and are also necessary
37  to tokenize line by line.  We can have different patterns apply to different
38  modes - i.e. looking for documentation while in comment mode.
39
40  Attributes:
41    regex: The regular expression representing this matcher.
42    type: The type of token indicated by a successful match.
43    result_mode: The mode to move to after a successful match.
44  """
45
46  def __init__(self, regex, token_type, result_mode=None, line_start=False):
47    """Create a new matcher template.
48
49    Args:
50      regex: The regular expression to match.
51      token_type: The type of token a successful match indicates.
52      result_mode: What mode to change to after a successful match.  Defaults to
53        None, which means to not change the current mode.
54      line_start: Whether this matcher should only match string at the start
55        of a line.
56    """
57    self.regex = regex
58    self.type = token_type
59    self.result_mode = result_mode
60    self.line_start = line_start
61