cpython/Lib/lib2to3/fixes/fix_apply.py

71 lines
2.4 KiB
Python

# Copyright 2006 Google, Inc. All Rights Reserved.
# Licensed to PSF under a Contributor Agreement.
"""Fixer for apply().
This converts apply(func, v, k) into (func)(*v, **k)."""
# Local imports
from .. import pytree
from ..pgen2 import token
from .. import fixer_base
from ..fixer_util import Call, Comma, parenthesize
class FixApply(fixer_base.BaseFix):
BM_compatible = True
PATTERN = """
power< 'apply'
trailer<
'('
arglist<
(not argument<NAME '=' any>) func=any ','
(not argument<NAME '=' any>) args=any [','
(not argument<NAME '=' any>) kwds=any] [',']
>
')'
>
>
"""
def transform(self, node, results):
syms = self.syms
assert results
func = results["func"]
args = results["args"]
kwds = results.get("kwds")
# I feel like we should be able to express this logic in the
# PATTERN above but I don't know how to do it so...
if args:
if args.type == self.syms.star_expr:
return # Make no change.
if (args.type == self.syms.argument and
args.children[0].value == '**'):
return # Make no change.
if kwds and (kwds.type == self.syms.argument and
kwds.children[0].value == '**'):
return # Make no change.
prefix = node.prefix
func = func.clone()
if (func.type not in (token.NAME, syms.atom) and
(func.type != syms.power or
func.children[-2].type == token.DOUBLESTAR)):
# Need to parenthesize
func = parenthesize(func)
func.prefix = ""
args = args.clone()
args.prefix = ""
if kwds is not None:
kwds = kwds.clone()
kwds.prefix = ""
l_newargs = [pytree.Leaf(token.STAR, "*"), args]
if kwds is not None:
l_newargs.extend([Comma(),
pytree.Leaf(token.DOUBLESTAR, "**"),
kwds])
l_newargs[-2].prefix = " " # that's the ** token
# XXX Sometimes we could be cleverer, e.g. apply(f, (x, y) + t)
# can be translated into f(x, y, *t) instead of f(*(x, y) + t)
#new = pytree.Node(syms.power, (func, ArgList(l_newargs)))
return Call(func, l_newargs, prefix=prefix)