fix_apply.py revision 84ad84e0bb15e7c64109e88060afdcb60ae7b740 
1# Copyright 2006 Google, Inc. All Rights Reserved.
2# Licensed to PSF under a Contributor Agreement.
3
4"""Fixer for apply().
5
6This converts apply(func, v, k) into (func)(*v, **k)."""
7
8# Local imports
9from .. import pytree
10from ..pgen2 import token
11from .. import fixer_base
12from ..fixer_util import Call, Comma, parenthesize
13
14class FixApply(fixer_base.BaseFix):
15
16    PATTERN = """
17    power< 'apply'
18        trailer<
19            '('
20            arglist<
21                (not argument<NAME '=' any>) func=any ','
22                (not argument<NAME '=' any>) args=any [','
23                (not argument<NAME '=' any>) kwds=any] [',']
24            >
25            ')'
26        >
27    >
28    """
29
30    def transform(self, node, results):
31        syms = self.syms
32        assert results
33        func = results["func"]
34        args = results["args"]
35        kwds = results.get("kwds")
36        prefix = node.get_prefix()
37        func = func.clone()
38        if (func.type not in (token.NAME, syms.atom) and
39            (func.type != syms.power or
40             func.children[-2].type == token.DOUBLESTAR)):
41            # Need to parenthesize
42            func = parenthesize(func)
43        func.set_prefix("")
44        args = args.clone()
45        args.set_prefix("")
46        if kwds is not None:
47            kwds = kwds.clone()
48            kwds.set_prefix("")
49        l_newargs = [pytree.Leaf(token.STAR, u"*"), args]
50        if kwds is not None:
51            l_newargs.extend([Comma(),
52                              pytree.Leaf(token.DOUBLESTAR, u"**"),
53                              kwds])
54            l_newargs[-2].set_prefix(u" ") # that's the ** token
55        # XXX Sometimes we could be cleverer, e.g. apply(f, (x, y) + t)
56        # can be translated into f(x, y, *t) instead of f(*(x, y) + t)
57        #new = pytree.Node(syms.power, (func, ArgList(l_newargs)))
58        return Call(func, l_newargs, prefix=prefix)
59