mirror of https://github.com/python/cpython
92 lines
3.0 KiB
Python
92 lines
3.0 KiB
Python
# Copyright 2007 Google, Inc. All Rights Reserved.
|
|
# Licensed to PSF under a Contributor Agreement.
|
|
|
|
"""Fixer that changes map(F, ...) into list(map(F, ...)) unless there
|
|
exists a 'from future_builtins import map' statement in the top-level
|
|
namespace.
|
|
|
|
As a special case, map(None, X) is changed into list(X). (This is
|
|
necessary because the semantics are changed in this case -- the new
|
|
map(None, X) is equivalent to [(x,) for x in X].)
|
|
|
|
We avoid the transformation (except for the special case mentioned
|
|
above) if the map() call is directly contained in iter(<>), list(<>),
|
|
tuple(<>), sorted(<>), ...join(<>), or for V in <>:.
|
|
|
|
NOTE: This is still not correct if the original code was depending on
|
|
map(F, X, Y, ...) to go on until the longest argument is exhausted,
|
|
substituting None for missing values -- like zip(), it now stops as
|
|
soon as the shortest argument is exhausted.
|
|
"""
|
|
|
|
# Local imports
|
|
from ..pgen2 import token
|
|
from .. import fixer_base
|
|
from ..fixer_util import Name, Call, ListComp, in_special_context
|
|
from ..pygram import python_symbols as syms
|
|
|
|
class FixMap(fixer_base.ConditionalFix):
|
|
BM_compatible = True
|
|
|
|
PATTERN = """
|
|
map_none=power<
|
|
'map'
|
|
trailer< '(' arglist< 'None' ',' arg=any [','] > ')' >
|
|
>
|
|
|
|
|
map_lambda=power<
|
|
'map'
|
|
trailer<
|
|
'('
|
|
arglist<
|
|
lambdef< 'lambda'
|
|
(fp=NAME | vfpdef< '(' fp=NAME ')'> ) ':' xp=any
|
|
>
|
|
','
|
|
it=any
|
|
>
|
|
')'
|
|
>
|
|
>
|
|
|
|
|
power<
|
|
'map' trailer< '(' [arglist=any] ')' >
|
|
>
|
|
"""
|
|
|
|
skip_on = 'future_builtins.map'
|
|
|
|
def transform(self, node, results):
|
|
if self.should_skip(node):
|
|
return
|
|
|
|
if node.parent.type == syms.simple_stmt:
|
|
self.warning(node, "You should use a for loop here")
|
|
new = node.clone()
|
|
new.prefix = u""
|
|
new = Call(Name(u"list"), [new])
|
|
elif "map_lambda" in results:
|
|
new = ListComp(results["xp"].clone(),
|
|
results["fp"].clone(),
|
|
results["it"].clone())
|
|
else:
|
|
if "map_none" in results:
|
|
new = results["arg"].clone()
|
|
else:
|
|
if "arglist" in results:
|
|
args = results["arglist"]
|
|
if args.type == syms.arglist and \
|
|
args.children[0].type == token.NAME and \
|
|
args.children[0].value == "None":
|
|
self.warning(node, "cannot convert map(None, ...) "
|
|
"with multiple arguments because map() "
|
|
"now truncates to the shortest sequence")
|
|
return
|
|
if in_special_context(node):
|
|
return None
|
|
new = node.clone()
|
|
new.prefix = u""
|
|
new = Call(Name(u"list"), [new])
|
|
new.prefix = node.prefix
|
|
return new
|