parenthesis_nester.py 文件源码

def __init__(self):
        nest = pypar.nestedExpr
        g = pypar.Forward()
        nestedParens = nest('(', ')')
        nestedBrackets = nest('[', ']')
        nestedCurlies = nest('{', '}')
        nest_grammar = nestedParens | nestedBrackets | nestedCurlies

        parens = "(){}[]"
        letters = ''.join([x for x in pypar.printables
                           if x not in parens])
        word = pypar.Word(letters)

        g = pypar.OneOrMore(word | nest_grammar)
        self.grammar = g