143 lines
3.9 KiB
Python
143 lines
3.9 KiB
Python
#!/usr/bin/python
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__all__ = ('parse_checks', 'BooleanParser')
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try: from pyparsing import *
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except ImportError: from utils.pyparsing import *
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def __make_parser():
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key = Word(alphas, alphanums+"_-")
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value = Word(alphanums + "-.,_=<>!@$%^&*[]{}:;|/'") | QuotedString('"')
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return Dict(ZeroOrMore(Group( key + Optional( Suppress("=") + value, default=True ) ) ))
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__checkparser = __make_parser()
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def parse_checks(string):
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"""
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from parsers import parse_checks
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>>> parse_checks('dependent=5a,no dependent="5a && 4a" dog="Roaming Rover" name=Robert foo bar')
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([(['dependent', '5a,no'], {}), (['dependent', '5a && 4a'], {}), (['dog', 'Roaming Rover'], {}), (['name', 'Robert'], {}), (['foo', True], {}), (['bar', True], {})], {'dependent': [('5a,no', 0), ('5a && 4a', 1)], 'foo': [(True, 4)], 'bar': [(True, 5)], 'dog': [('Roaming Rover', 2)], 'name': [('Robert', 3)]})
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"""
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return __checkparser.parseString(string, parseAll=True)
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# -=-=-=-=-=-=-=-=-=-=-=-=-=-=-
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# - Boolean Expression Parser -
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# -=-=-=-=-=-=-=-=-=-=-=-=-=-=-
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class BoolOperand(object):
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def __init__(self, t):
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self.args = t[0][0::2]
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def __str__(self):
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sep = " %s " % self.reprsymbol
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return "(" + sep.join(map(str, self.args)) + ")"
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class BoolAnd(BoolOperand):
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reprsymbol = '&&'
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def __nonzero__(self):
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for a in self.args:
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if not bool(a):
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return False
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return True
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class BoolOr(BoolOperand):
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reprsymbol = '||'
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def __nonzero__(self):
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for a in self.args:
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if bool(a):
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return True
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return False
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class BoolNot(BoolOperand):
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def __init__(self,t):
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self.arg = t[0][1]
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def __str__(self):
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return "!" + str(self.arg)
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def __nonzero__(self):
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return not bool(self.arg)
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class Checker(object):
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"Simple wrapper to call a specific function, passing in args and kwargs each time"
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def __init__(self, func, expr, *args, **kwargs):
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self.func = func
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self.expr = expr
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self.args = args
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self.kwargs = kwargs
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def __nonzero__(self):
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return self.func(self.expr, *self.args, **self.kwargs)
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def __hash__(self):
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return hash(self.expr)
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def __unicode__(self):
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try: fname=self.func.func_name
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except: fname="TestExpr"
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return "%s('%s')" % (fname, self.expr)
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__str__ = __unicode__
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class BooleanParser(object):
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"""Simple boolean parser
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>>> def foo(x):
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... if x == '1': return True
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... return False
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...
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>>> foo('1')
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True
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>>> foo('0')
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False
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>>> p = BooleanParser(foo)
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>>> p.parse('1 and 0')
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False
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>>> p.parse('1 and 1')
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True
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>>> p.parse('1 or 1')
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True
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>>> p.parse('0 or 1')
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True
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>>> p.parse('0 or 0')
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False
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>>> p.parse('(0 or 0) and 1')
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False
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>>> p.parse('(0 or 0) and (1)')
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False
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>>> p.parse('(0 or 1) and (1)')
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True
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>>> p.parse('(0 or 0) or (1)')
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True
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"""
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def __init__(self, func, *args, **kwargs): # treats kwarg boolOperand specially!
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self.args = args
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self.kwargs = kwargs
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self.func = func
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if "boolOperand" in kwargs:
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boolOperand = kwargs["boolOperand"]
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del kwargs["boolOperand"]
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else:
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boolOperand = Word(alphanums + "-.,_=<>!@$%^&*[]{}:;|/\\")
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boolOperand = boolOperand.setParseAction(self._check)
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self.boolExpr = infixNotation(boolOperand,
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[
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("not ", 1, opAssoc.RIGHT, BoolNot),
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("or", 2, opAssoc.LEFT, BoolOr),
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("and", 2, opAssoc.LEFT, BoolAnd),
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])
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def _check(self, string, location, tokens):
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checker = Checker(self.func, tokens[0], *self.args, **self.kwargs)
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tokens[0] = checker
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def parse(self, code):
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if not code or not code.strip():
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return False
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return bool(self.boolExpr.parseString(code)[0])
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def toString(self, code):
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return str(self.boolExpr.parseString(code)[0])
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if __name__ == '__main__':
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import doctest
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doctest.testmod()
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