yacc.py 文件源码

def signature(self):
        try:
            from hashlib import md5
        except ImportError:
            from md5 import md5
        try:
            sig = md5()
            if self.start:
                sig.update(self.start.encode('latin-1'))
            if self.prec:
                sig.update("".join(["".join(p) for p in self.prec]).encode('latin-1'))
            if self.tokens:
                sig.update(" ".join(self.tokens).encode('latin-1'))
            for f in self.pfuncs:
                if f[3]:
                    sig.update(f[3].encode('latin-1'))
        except (TypeError,ValueError):
            pass
        return sig.digest()

    # -----------------------------------------------------------------------------
    # validate_file()
    #
    # This method checks to see if there are duplicated p_rulename() functions
    # in the parser module file.  Without this function, it is really easy for
    # users to make mistakes by cutting and pasting code fragments (and it's a real
    # bugger to try and figure out why the resulting parser doesn't work).  Therefore,
    # we just do a little regular expression pattern matching of def statements
    # to try and detect duplicates.
    # -----------------------------------------------------------------------------