Python code coverage for Lib/lib2to3/fixes/fix_next.py

#	count	content
1	n/a	"""Fixer for it.next() -> next(it), per PEP 3114."""
2	n/a	# Author: Collin Winter
3	n/a
4	n/a	# Things that currently aren't covered:
5	n/a	# - listcomp "next" names aren't warned
6	n/a	# - "with" statement targets aren't checked
7	n/a
8	n/a	# Local imports
9	n/a	from ..pgen2 import token
10	n/a	from ..pygram import python_symbols as syms
11	n/a	from .. import fixer_base
12	n/a	from ..fixer_util import Name, Call, find_binding
13	n/a
14	n/a	bind_warning = "Calls to builtin next() possibly shadowed by global binding"
15	n/a
16	n/a
17	n/a	class FixNext(fixer_base.BaseFix):
18	n/a	BM_compatible = True
19	n/a	PATTERN = """
20	n/a	power< base=any+ trailer< '.' attr='next' > trailer< '(' ')' > >
21	n/a	\|
22	n/a	power< head=any+ trailer< '.' attr='next' > not trailer< '(' ')' > >
23	n/a	\|
24	n/a	classdef< 'class' any+ ':'
25	n/a	suite< any*
26	n/a	funcdef< 'def'
27	n/a	name='next'
28	n/a	parameters< '(' NAME ')' > any+ >
29	n/a	any* > >
30	n/a	\|
31	n/a	global=global_stmt< 'global' any* 'next' any* >
32	n/a	"""
33	n/a
34	n/a	order = "pre" # Pre-order tree traversal
35	n/a
36	n/a	def start_tree(self, tree, filename):
37	n/a	super(FixNext, self).start_tree(tree, filename)
38	n/a
39	n/a	n = find_binding('next', tree)
40	n/a	if n:
41	n/a	self.warning(n, bind_warning)
42	n/a	self.shadowed_next = True
43	n/a	else:
44	n/a	self.shadowed_next = False
45	n/a
46	n/a	def transform(self, node, results):
47	n/a	assert results
48	n/a
49	n/a	base = results.get("base")
50	n/a	attr = results.get("attr")
51	n/a	name = results.get("name")
52	n/a
53	n/a	if base:
54	n/a	if self.shadowed_next:
55	n/a	attr.replace(Name("__next__", prefix=attr.prefix))
56	n/a	else:
57	n/a	base = [n.clone() for n in base]
58	n/a	base[0].prefix = ""
59	n/a	node.replace(Call(Name("next", prefix=node.prefix), base))
60	n/a	elif name:
61	n/a	n = Name("__next__", prefix=name.prefix)
62	n/a	name.replace(n)
63	n/a	elif attr:
64	n/a	# We don't do this transformation if we're assigning to "x.next".
65	n/a	# Unfortunately, it doesn't seem possible to do this in PATTERN,
66	n/a	# so it's being done here.
67	n/a	if is_assign_target(node):
68	n/a	head = results["head"]
69	n/a	if "".join([str(n) for n in head]).strip() == '__builtin__':
70	n/a	self.warning(node, bind_warning)
71	n/a	return
72	n/a	attr.replace(Name("__next__"))
73	n/a	elif "global" in results:
74	n/a	self.warning(node, bind_warning)
75	n/a	self.shadowed_next = True
76	n/a
77	n/a
78	n/a	### The following functions help test if node is part of an assignment
79	n/a	### target.
80	n/a
81	n/a	def is_assign_target(node):
82	n/a	assign = find_assign(node)
83	n/a	if assign is None:
84	n/a	return False
85	n/a
86	n/a	for child in assign.children:
87	n/a	if child.type == token.EQUAL:
88	n/a	return False
89	n/a	elif is_subtree(child, node):
90	n/a	return True
91	n/a	return False
92	n/a
93	n/a	def find_assign(node):
94	n/a	if node.type == syms.expr_stmt:
95	n/a	return node
96	n/a	if node.type == syms.simple_stmt or node.parent is None:
97	n/a	return None
98	n/a	return find_assign(node.parent)
99	n/a
100	n/a	def is_subtree(root, node):
101	n/a	if root == node:
102	n/a	return True
103	n/a	return any(is_subtree(c, node) for c in root.children)