56 lines
1.6 KiB
Python
56 lines
1.6 KiB
Python
|
#-----------------------------------------------------------------
|
||
|
|
# plyparser.py
|
||
|
|
#
|
||
|
|
# PLYParser class and other utilites for simplifying programming
|
||
|
|
# parsers with PLY
|
||
|
|
#
|
||
|
|
# Copyright (C) 2008-2015, Eli Bendersky
|
||
|
|
# License: BSD
|
||
|
|
#-----------------------------------------------------------------
|
||
|
|
|
||
|
|
|
||
|
|
class Coord(object):
|
||
|
|
""" Coordinates of a syntactic element. Consists of:
|
||
|
|
- File name
|
||
|
|
- Line number
|
||
|
|
- (optional) column number, for the Lexer
|
||
|
|
"""
|
||
|
|
__slots__ = ('file', 'line', 'column', '__weakref__')
|
||
|
|
def __init__(self, file, line, column=None):
|
||
|
|
self.file = file
|
||
|
|
self.line = line
|
||
|
|
self.column = column
|
||
|
|
|
||
|
|
def __str__(self):
|
||
|
|
str = "%s:%s" % (self.file, self.line)
|
||
|
|
if self.column: str += ":%s" % self.column
|
||
|
|
return str
|
||
|
|
|
||
|
|
|
||
|
|
class ParseError(Exception): pass
|
||
|
|
|
||
|
|
|
||
|
|
class PLYParser(object):
|
||
|
|
def _create_opt_rule(self, rulename):
|
||
|
|
""" Given a rule name, creates an optional ply.yacc rule
|
||
|
|
for it. The name of the optional rule is
|
||
|
|
<rulename>_opt
|
||
|
|
"""
|
||
|
|
optname = rulename + '_opt'
|
||
|
|
|
||
|
|
def optrule(self, p):
|
||
|
|
p[0] = p[1]
|
||
|
|
|
||
|
|
optrule.__doc__ = '%s : empty\n| %s' % (optname, rulename)
|
||
|
|
optrule.__name__ = 'p_%s' % optname
|
||
|
|
setattr(self.__class__, optrule.__name__, optrule)
|
||
|
|
|
||
|
|
def _coord(self, lineno, column=None):
|
||
|
|
return Coord(
|
||
|
|
file=self.clex.filename,
|
||
|
|
line=lineno,
|
||
|
|
column=column)
|
||
|
|
|
||
|
|
def _parse_error(self, msg, coord):
|
||
|
|
raise ParseError("%s: %s" % (coord, msg))
|