56 lines
1.5 KiB
Python
56 lines
1.5 KiB
Python
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#-----------------------------------------------------------------
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# plyparser.py
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#
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# PLYParser class and other utilites for simplifying programming
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# parsers with PLY
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#
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# Copyright (C) 2008-2012, Eli Bendersky
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# License: BSD
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#-----------------------------------------------------------------
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class Coord(object):
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""" Coordinates of a syntactic element. Consists of:
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- File name
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- Line number
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- (optional) column number, for the Lexer
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"""
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def __init__(self, file, line, column=None):
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self.file = file
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self.line = line
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self.column = column
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def __str__(self):
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str = "%s:%s" % (self.file, self.line)
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if self.column: str += ":%s" % self.column
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return str
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class ParseError(Exception): pass
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class PLYParser(object):
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def _create_opt_rule(self, rulename):
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""" Given a rule name, creates an optional ply.yacc rule
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for it. The name of the optional rule is
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<rulename>_opt
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"""
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optname = rulename + '_opt'
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def optrule(self, p):
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p[0] = p[1]
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optrule.__doc__ = '%s : empty\n| %s' % (optname, rulename)
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optrule.__name__ = 'p_%s' % optname
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setattr(self.__class__, optrule.__name__, optrule)
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def _coord(self, lineno, column=None):
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return Coord(
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file=self.clex.filename,
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line=lineno,
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column=column)
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def _parse_error(self, msg, coord):
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raise ParseError("%s: %s" % (coord, msg))
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