Source Code for Module lepl.stream.maxdepth

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11  # The Original Code is LEPL (http://www.acooke.org/lepl) 
12  # The Initial Developer of the Original Code is Andrew Cooke. 
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14  # Andrew Cooke (andrew@acooke.org). All Rights Reserved. 
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28   
29  ''' 
30  Raise an exception if the stream is not consumed entirely. 
31  ''' 
32   
33  from lepl.stream.core import s_empty, s_fmt, s_deepest, s_next 
34  from lepl.matchers.support import trampoline_matcher_factory 
35   
36   
37  @trampoline_matcher_factory() 
38 -def FullFirstMatch(matcher, eos=True): 
39      ''' 
40      Raise an exception if the first match fails (if eos=False) or does not 
41      consume the entire input stream (eos=True).  The exception includes  
42      information about the location of the deepest match. 
43       
44      This only works for the first match because we cannot reset the stream 
45      facade for subsequent matches (also, if you want multiple matches you 
46      probably want more sophisticated error handling than this). 
47      ''' 
48       
49      def _matcher(support, stream1): 
50          # set default maxdepth 
51          s_next(stream1, count=0) 
52          # first match 
53          generator = matcher._match(stream1) 
54          try: 
55              (result2, stream2) = yield generator 
56              if eos and not s_empty(stream2): 
57                  raise FullFirstMatchException(stream2) 
58              else: 
59                  yield (result2, stream2) 
60          except StopIteration: 
61              raise FullFirstMatchException(stream1) 
62           
63          # subsequent matches: 
64          while True: 
65              result = yield generator 
66              yield result 
67   
68      return _matcher 
69   
70   
71 -class FullFirstMatchException(Exception): 
72      ''' 
73      The exception raised by `FullFirstMatch`.  This includes information 
74      about the deepest point read in the stream.  
75      ''' 
76       
77 -    def __init__(self, stream): 
78          super(FullFirstMatchException, self).__init__( 
79              s_fmt(s_deepest(stream), 
80                       'The match failed in {filename} at {rest} ({location}).')) 
81