python - pyparsing Optional() & Optional() allows repetitions -

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i've simple grammar:

word = word(alphanums + '_') with_stmt = suppress('with') + oneormore(group(word('key') + suppress('=') + word('value')))('overrides') using_stmt = suppress('using') + regex('id-[0-9a-f]{8}')('id') modifiers = optional(with_stmt('with_stmt')) & optional(using_stmt('using_stmt')) pattern = stringstart() + modifiers + stringend()

it seems optional() & optional() erroneously allows multiple repetitions of either modifier, , labels last one:

>>> print dict(pattern.parsestring('with foo=bar bing=baz using id-deadbeef using id-feedfeed')) {   'with_stmt': (     [       (['foo', 'bar'], {'value': [('bar', 1)], 'key': [('foo', 0)]}),        (['bing', 'baz'], {'value': [('baz', 1)], 'key': [('bing', 0)]})     ],     {'overrides':        [(([         (['foo', 'bar'], {'value': [('bar', 1)], 'key': [('foo', 0)]}),         (['bing', 'baz'], {'value': [('baz', 1)], 'key': [('bing', 0)]})       ], {}), 0)]     }   ),    'overrides':      (       [(['foo', 'bar'], {'value': [('bar', 1)], 'key': [('foo', 0)]}),       (['bing', 'baz'], {'value': [('baz', 1)], 'key': [('bing', 0)]})], {}     ),   'id': (['id-deadbeef', 'id-feedfeed'], {}),   'using_stmt': (['id-deadbeef', 'id-feedfeed'], {'id': [('id-deadbeef', 0), ('id-feedfeed', 1)]}) }

using_stmt matches both id-deadbeef , id-feedfeed instead of throwing error @ using id-feedfeed.

strangely enough, if make modifiers non-optional, repitition problem goes away , parsing fails expected:

>>> dict(pattern.parsestring('with foo=bar bing=baz using id-deadbeef using id-feedfeed')) traceback (most recent call last):   file "parse.py", line 10, in <module>     print dict(pattern.parsestring('with foo=bar bing=baz using id-deadbeef using id-feedfeed'))   file "/path/to/lib/python2.7/site-packages/pyparsing.py", line 1139, in parsestring     raise exc pyparsing.parseexception: expected end of text (at char 40), (line:1, col:41)

switching + instead of & causes fail expected. with_stmt exhibits same problem, , making non-optional fixes it.

what marking pattern optional allows repetition inside each()?

this bug in pyparsing's each class - fixed in 2.0.6.


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