mirror of https://github.com/python/cpython
103 lines
3.1 KiB
Python
103 lines
3.1 KiB
Python
|
"""Fixer for it.next() -> next(it), per PEP 3114."""
|
||
|
|
# Author: Collin Winter
|
||
|
|
|
||
|
|
# Things that currently aren't covered:
|
||
|
|
# - listcomp "next" names aren't warned
|
||
|
|
# - "with" statement targets aren't checked
|
||
|
|
|
||
|
|
# Local imports
|
||
|
|
from ..pgen2 import token
|
||
|
|
from ..pygram import python_symbols as syms
|
||
|
|
from .. import fixer_base
|
||
|
|
from ..fixer_util import Name, Call, find_binding
|
||
|
|
|
||
|
|
bind_warning = "Calls to builtin next() possibly shadowed by global binding"
|
||
|
|
|
||
|
|
|
||
|
|
class FixNext(fixer_base.BaseFix):
|
||
|
|
PATTERN = """
|
||
|
|
power< base=any+ trailer< '.' attr='next' > trailer< '(' ')' > >
|
||
|
|
|
|
||
|
|
power< head=any+ trailer< '.' attr='next' > not trailer< '(' ')' > >
|
||
|
|
|
|
||
|
|
classdef< 'class' any+ ':'
|
||
|
|
suite< any*
|
||
|
|
funcdef< 'def'
|
||
|
|
name='next'
|
||
|
|
parameters< '(' NAME ')' > any+ >
|
||
|
|
any* > >
|
||
|
|
|
|
||
|
|
global=global_stmt< 'global' any* 'next' any* >
|
||
|
|
"""
|
||
|
|
|
||
|
|
order = "pre" # Pre-order tree traversal
|
||
|
|
|
||
|
|
def start_tree(self, tree, filename):
|
||
|
|
super(FixNext, self).start_tree(tree, filename)
|
||
|
|
|
||
|
|
n = find_binding(u'next', tree)
|
||
|
|
if n:
|
||
|
|
self.warning(n, bind_warning)
|
||
|
|
self.shadowed_next = True
|
||
|
|
else:
|
||
|
|
self.shadowed_next = False
|
||
|
|
|
||
|
|
def transform(self, node, results):
|
||
|
|
assert results
|
||
|
|
|
||
|
|
base = results.get("base")
|
||
|
|
attr = results.get("attr")
|
||
|
|
name = results.get("name")
|
||
|
|
|
||
|
|
if base:
|
||
|
|
if self.shadowed_next:
|
||
|
|
attr.replace(Name(u"__next__", prefix=attr.prefix))
|
||
|
|
else:
|
||
|
|
base = [n.clone() for n in base]
|
||
|
|
base[0].prefix = u""
|
||
|
|
node.replace(Call(Name(u"next", prefix=node.prefix), base))
|
||
|
|
elif name:
|
||
|
|
n = Name(u"__next__", prefix=name.prefix)
|
||
|
|
name.replace(n)
|
||
|
|
elif attr:
|
||
|
|
# We don't do this transformation if we're assigning to "x.next".
|
||
|
|
# Unfortunately, it doesn't seem possible to do this in PATTERN,
|
||
|
|
# so it's being done here.
|
||
|
|
if is_assign_target(node):
|
||
|
|
head = results["head"]
|
||
|
|
if "".join([str(n) for n in head]).strip() == u'__builtin__':
|
||
|
|
self.warning(node, bind_warning)
|
||
|
|
return
|
||
|
|
attr.replace(Name(u"__next__"))
|
||
|
|
elif "global" in results:
|
||
|
|
self.warning(node, bind_warning)
|
||
|
|
self.shadowed_next = True
|
||
|
|
|
||
|
|
|
||
|
|
### The following functions help test if node is part of an assignment
|
||
|
|
### target.
|
||
|
|
|
||
|
|
def is_assign_target(node):
|
||
|
|
assign = find_assign(node)
|
||
|
|
if assign is None:
|
||
|
|
return False
|
||
|
|
|
||
|
|
for child in assign.children:
|
||
|
|
if child.type == token.EQUAL:
|
||
|
|
return False
|
||
|
|
elif is_subtree(child, node):
|
||
|
|
return True
|
||
|
|
return False
|
||
|
|
|
||
|
|
def find_assign(node):
|
||
|
|
if node.type == syms.expr_stmt:
|
||
|
|
return node
|
||
|
|
if node.type == syms.simple_stmt or node.parent is None:
|
||
|
|
return None
|
||
|
|
return find_assign(node.parent)
|
||
|
|
|
||
|
|
def is_subtree(root, node):
|
||
|
|
if root == node:
|
||
|
|
return True
|
||
|
|
return any(is_subtree(c, node) for c in root.children)
|