diff options
Diffstat (limited to 'trunk/src/examples/invRegex.py')
| -rw-r--r-- | trunk/src/examples/invRegex.py | 257 |
1 files changed, 0 insertions, 257 deletions
diff --git a/trunk/src/examples/invRegex.py b/trunk/src/examples/invRegex.py deleted file mode 100644 index b6fe1f1..0000000 --- a/trunk/src/examples/invRegex.py +++ /dev/null @@ -1,257 +0,0 @@ -#
-# invRegex.py
-#
-# Copyright 2008, Paul McGuire
-#
-# pyparsing script to expand a regular expression into all possible matching strings
-# Supports:
-# - {n} and {m,n} repetition, but not unbounded + or * repetition
-# - ? optional elements
-# - [] character ranges
-# - () grouping
-# - | alternation
-#
-__all__ = ["count","invert"]
-
-from pyparsing import (Literal, oneOf, printables, ParserElement, Combine,
- SkipTo, infixNotation, ParseFatalException, Word, nums, opAssoc,
- Suppress, ParseResults, srange)
-
-class CharacterRangeEmitter(object):
- def __init__(self,chars):
- # remove duplicate chars in character range, but preserve original order
- seen = set()
- self.charset = "".join( seen.add(c) or c for c in chars if c not in seen )
- def __str__(self):
- return '['+self.charset+']'
- def __repr__(self):
- return '['+self.charset+']'
- def makeGenerator(self):
- def genChars():
- for s in self.charset:
- yield s
- return genChars
-
-class OptionalEmitter(object):
- def __init__(self,expr):
- self.expr = expr
- def makeGenerator(self):
- def optionalGen():
- yield ""
- for s in self.expr.makeGenerator()():
- yield s
- return optionalGen
-
-class DotEmitter(object):
- def makeGenerator(self):
- def dotGen():
- for c in printables:
- yield c
- return dotGen
-
-class GroupEmitter(object):
- def __init__(self,exprs):
- self.exprs = ParseResults(exprs)
- def makeGenerator(self):
- def groupGen():
- def recurseList(elist):
- if len(elist)==1:
- for s in elist[0].makeGenerator()():
- yield s
- else:
- for s in elist[0].makeGenerator()():
- for s2 in recurseList(elist[1:]):
- yield s + s2
- if self.exprs:
- for s in recurseList(self.exprs):
- yield s
- return groupGen
-
-class AlternativeEmitter(object):
- def __init__(self,exprs):
- self.exprs = exprs
- def makeGenerator(self):
- def altGen():
- for e in self.exprs:
- for s in e.makeGenerator()():
- yield s
- return altGen
-
-class LiteralEmitter(object):
- def __init__(self,lit):
- self.lit = lit
- def __str__(self):
- return "Lit:"+self.lit
- def __repr__(self):
- return "Lit:"+self.lit
- def makeGenerator(self):
- def litGen():
- yield self.lit
- return litGen
-
-def handleRange(toks):
- return CharacterRangeEmitter(srange(toks[0]))
-
-def handleRepetition(toks):
- toks=toks[0]
- if toks[1] in "*+":
- raise ParseFatalException("",0,"unbounded repetition operators not supported")
- if toks[1] == "?":
- return OptionalEmitter(toks[0])
- if "count" in toks:
- return GroupEmitter([toks[0]] * int(toks.count))
- if "minCount" in toks:
- mincount = int(toks.minCount)
- maxcount = int(toks.maxCount)
- optcount = maxcount - mincount
- if optcount:
- opt = OptionalEmitter(toks[0])
- for i in range(1,optcount):
- opt = OptionalEmitter(GroupEmitter([toks[0],opt]))
- return GroupEmitter([toks[0]] * mincount + [opt])
- else:
- return [toks[0]] * mincount
-
-def handleLiteral(toks):
- lit = ""
- for t in toks:
- if t[0] == "\\":
- if t[1] == "t":
- lit += '\t'
- else:
- lit += t[1]
- else:
- lit += t
- return LiteralEmitter(lit)
-
-def handleMacro(toks):
- macroChar = toks[0][1]
- if macroChar == "d":
- return CharacterRangeEmitter("0123456789")
- elif macroChar == "w":
- return CharacterRangeEmitter(srange("[A-Za-z0-9_]"))
- elif macroChar == "s":
- return LiteralEmitter(" ")
- else:
- raise ParseFatalException("",0,"unsupported macro character (" + macroChar + ")")
-
-def handleSequence(toks):
- return GroupEmitter(toks[0])
-
-def handleDot():
- return CharacterRangeEmitter(printables)
-
-def handleAlternative(toks):
- return AlternativeEmitter(toks[0])
-
-
-_parser = None
-def parser():
- global _parser
- if _parser is None:
- ParserElement.setDefaultWhitespaceChars("")
- lbrack,rbrack,lbrace,rbrace,lparen,rparen,colon,qmark = map(Literal,"[]{}():?")
-
- reMacro = Combine("\\" + oneOf(list("dws")))
- escapedChar = ~reMacro + Combine("\\" + oneOf(list(printables)))
- reLiteralChar = "".join(c for c in printables if c not in r"\[]{}().*?+|") + " \t"
-
- reRange = Combine(lbrack + SkipTo(rbrack,ignore=escapedChar) + rbrack)
- reLiteral = ( escapedChar | oneOf(list(reLiteralChar)) )
- reNonCaptureGroup = Suppress("?:")
- reDot = Literal(".")
- repetition = (
- ( lbrace + Word(nums)("count") + rbrace ) |
- ( lbrace + Word(nums)("minCount")+","+ Word(nums)("maxCount") + rbrace ) |
- oneOf(list("*+?"))
- )
-
- reRange.setParseAction(handleRange)
- reLiteral.setParseAction(handleLiteral)
- reMacro.setParseAction(handleMacro)
- reDot.setParseAction(handleDot)
-
- reTerm = ( reLiteral | reRange | reMacro | reDot | reNonCaptureGroup)
- reExpr = infixNotation( reTerm,
- [
- (repetition, 1, opAssoc.LEFT, handleRepetition),
- (None, 2, opAssoc.LEFT, handleSequence),
- (Suppress('|'), 2, opAssoc.LEFT, handleAlternative),
- ]
- )
- _parser = reExpr
-
- return _parser
-
-def count(gen):
- """Simple function to count the number of elements returned by a generator."""
- return sum(1 for _ in gen)
-
-def invert(regex):
- """Call this routine as a generator to return all the strings that
- match the input regular expression.
- for s in invert("[A-Z]{3}\d{3}"):
- print s
- """
- invReGenerator = GroupEmitter(parser().parseString(regex)).makeGenerator()
- return invReGenerator()
-
-def main():
- tests = r"""
- [A-EA]
- [A-D]*
- [A-D]{3}
- X[A-C]{3}Y
- X[A-C]{3}\(
- X\d
- foobar\d\d
- foobar{2}
- foobar{2,9}
- fooba[rz]{2}
- (foobar){2}
- ([01]\d)|(2[0-5])
- (?:[01]\d)|(2[0-5])
- ([01]\d\d)|(2[0-4]\d)|(25[0-5])
- [A-C]{1,2}
- [A-C]{0,3}
- [A-C]\s[A-C]\s[A-C]
- [A-C]\s?[A-C][A-C]
- [A-C]\s([A-C][A-C])
- [A-C]\s([A-C][A-C])?
- [A-C]{2}\d{2}
- @|TH[12]
- @(@|TH[12])?
- @(@|TH[12]|AL[12]|SP[123]|TB(1[0-9]?|20?|[3-9]))?
- @(@|TH[12]|AL[12]|SP[123]|TB(1[0-9]?|20?|[3-9])|OH(1[0-9]?|2[0-9]?|30?|[4-9]))?
- (([ECMP]|HA|AK)[SD]|HS)T
- [A-CV]{2}
- A[cglmrstu]|B[aehikr]?|C[adeflmorsu]?|D[bsy]|E[rsu]|F[emr]?|G[ade]|H[efgos]?|I[nr]?|Kr?|L[airu]|M[dgnot]|N[abdeiop]?|Os?|P[abdmortu]?|R[abefghnu]|S[bcegimnr]?|T[abcehilm]|Uu[bhopqst]|U|V|W|Xe|Yb?|Z[nr]
- (a|b)|(x|y)
- (a|b) (x|y)
- [ABCDEFG](?:#|##|b|bb)?(?:maj|min|m|sus|aug|dim)?[0-9]?(?:/[ABCDEFG](?:#|##|b|bb)?)?
- (Fri|Mon|S(atur|un)|T(hur|ue)s|Wednes)day
- A(pril|ugust)|((Dec|Nov|Sept)em|Octo)ber|(Febr|Jan)uary|Ju(ly|ne)|Ma(rch|y)
- """.split('\n')
-
- for t in tests:
- t = t.strip()
- if not t: continue
- print('-'*50)
- print(t)
- try:
- num = count(invert(t))
- print(num)
- maxprint = 30
- for s in invert(t):
- print(s)
- maxprint -= 1
- if not maxprint:
- break
- except ParseFatalException as pfe:
- print(pfe.msg)
- print('')
- continue
- print('')
-
-if __name__ == "__main__":
- main()
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