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

#	count	content
1	n/a	"""Fixer for function definitions with tuple parameters.
2	n/a
3	n/a	def func(((a, b), c), d):
4	n/a	...
5	n/a
6	n/a	->
7	n/a
8	n/a	def func(x, d):
9	n/a	((a, b), c) = x
10	n/a	...
11	n/a
12	n/a	It will also support lambdas:
13	n/a
14	n/a	lambda (x, y): x + y -> lambda t: t[0] + t[1]
15	n/a
16	n/a	# The parens are a syntax error in Python 3
17	n/a	lambda (x): x + y -> lambda x: x + y
18	n/a	"""
19	n/a	# Author: Collin Winter
20	n/a
21	n/a	# Local imports
22	n/a	from .. import pytree
23	n/a	from ..pgen2 import token
24	n/a	from .. import fixer_base
25	n/a	from ..fixer_util import Assign, Name, Newline, Number, Subscript, syms
26	n/a
27	n/a	def is_docstring(stmt):
28	n/a	return isinstance(stmt, pytree.Node) and \
29	n/a	stmt.children[0].type == token.STRING
30	n/a
31	n/a	class FixTupleParams(fixer_base.BaseFix):
32	n/a	run_order = 4 #use a lower order since lambda is part of other
33	n/a	#patterns
34	n/a	BM_compatible = True
35	n/a
36	n/a	PATTERN = """
37	n/a	funcdef< 'def' any parameters< '(' args=any ')' >
38	n/a	['->' any] ':' suite=any+ >
39	n/a	\|
40	n/a	lambda=
41	n/a	lambdef< 'lambda' args=vfpdef< '(' inner=any ')' >
42	n/a	':' body=any
43	n/a	>
44	n/a	"""
45	n/a
46	n/a	def transform(self, node, results):
47	n/a	if "lambda" in results:
48	n/a	return self.transform_lambda(node, results)
49	n/a
50	n/a	new_lines = []
51	n/a	suite = results["suite"]
52	n/a	args = results["args"]
53	n/a	# This crap is so "def foo(...): x = 5; y = 7" is handled correctly.
54	n/a	# TODO(cwinter): suite-cleanup
55	n/a	if suite[0].children[1].type == token.INDENT:
56	n/a	start = 2
57	n/a	indent = suite[0].children[1].value
58	n/a	end = Newline()
59	n/a	else:
60	n/a	start = 0
61	n/a	indent = "; "
62	n/a	end = pytree.Leaf(token.INDENT, "")
63	n/a
64	n/a	# We need access to self for new_name(), and making this a method
65	n/a	# doesn't feel right. Closing over self and new_lines makes the
66	n/a	# code below cleaner.
67	n/a	def handle_tuple(tuple_arg, add_prefix=False):
68	n/a	n = Name(self.new_name())
69	n/a	arg = tuple_arg.clone()
70	n/a	arg.prefix = ""
71	n/a	stmt = Assign(arg, n.clone())
72	n/a	if add_prefix:
73	n/a	n.prefix = " "
74	n/a	tuple_arg.replace(n)
75	n/a	new_lines.append(pytree.Node(syms.simple_stmt,
76	n/a	[stmt, end.clone()]))
77	n/a
78	n/a	if args.type == syms.tfpdef:
79	n/a	handle_tuple(args)
80	n/a	elif args.type == syms.typedargslist:
81	n/a	for i, arg in enumerate(args.children):
82	n/a	if arg.type == syms.tfpdef:
83	n/a	# Without add_prefix, the emitted code is correct,
84	n/a	# just ugly.
85	n/a	handle_tuple(arg, add_prefix=(i > 0))
86	n/a
87	n/a	if not new_lines:
88	n/a	return
89	n/a
90	n/a	# This isn't strictly necessary, but it plays nicely with other fixers.
91	n/a	# TODO(cwinter) get rid of this when children becomes a smart list
92	n/a	for line in new_lines:
93	n/a	line.parent = suite[0]
94	n/a
95	n/a	# TODO(cwinter) suite-cleanup
96	n/a	after = start
97	n/a	if start == 0:
98	n/a	new_lines[0].prefix = " "
99	n/a	elif is_docstring(suite[0].children[start]):
100	n/a	new_lines[0].prefix = indent
101	n/a	after = start + 1
102	n/a
103	n/a	for line in new_lines:
104	n/a	line.parent = suite[0]
105	n/a	suite[0].children[after:after] = new_lines
106	n/a	for i in range(after+1, after+len(new_lines)+1):
107	n/a	suite[0].children[i].prefix = indent
108	n/a	suite[0].changed()
109	n/a
110	n/a	def transform_lambda(self, node, results):
111	n/a	args = results["args"]
112	n/a	body = results["body"]
113	n/a	inner = simplify_args(results["inner"])
114	n/a
115	n/a	# Replace lambda ((((x)))): x with lambda x: x
116	n/a	if inner.type == token.NAME:
117	n/a	inner = inner.clone()
118	n/a	inner.prefix = " "
119	n/a	args.replace(inner)
120	n/a	return
121	n/a
122	n/a	params = find_params(args)
123	n/a	to_index = map_to_index(params)
124	n/a	tup_name = self.new_name(tuple_name(params))
125	n/a
126	n/a	new_param = Name(tup_name, prefix=" ")
127	n/a	args.replace(new_param.clone())
128	n/a	for n in body.post_order():
129	n/a	if n.type == token.NAME and n.value in to_index:
130	n/a	subscripts = [c.clone() for c in to_index[n.value]]
131	n/a	new = pytree.Node(syms.power,
132	n/a	[new_param.clone()] + subscripts)
133	n/a	new.prefix = n.prefix
134	n/a	n.replace(new)
135	n/a
136	n/a
137	n/a	### Helper functions for transform_lambda()
138	n/a
139	n/a	def simplify_args(node):
140	n/a	if node.type in (syms.vfplist, token.NAME):
141	n/a	return node
142	n/a	elif node.type == syms.vfpdef:
143	n/a	# These look like vfpdef< '(' x ')' > where x is NAME
144	n/a	# or another vfpdef instance (leading to recursion).
145	n/a	while node.type == syms.vfpdef:
146	n/a	node = node.children[1]
147	n/a	return node
148	n/a	raise RuntimeError("Received unexpected node %s" % node)
149	n/a
150	n/a	def find_params(node):
151	n/a	if node.type == syms.vfpdef:
152	n/a	return find_params(node.children[1])
153	n/a	elif node.type == token.NAME:
154	n/a	return node.value
155	n/a	return [find_params(c) for c in node.children if c.type != token.COMMA]
156	n/a
157	n/a	def map_to_index(param_list, prefix=[], d=None):
158	n/a	if d is None:
159	n/a	d = {}
160	n/a	for i, obj in enumerate(param_list):
161	n/a	trailer = [Subscript(Number(str(i)))]
162	n/a	if isinstance(obj, list):
163	n/a	map_to_index(obj, trailer, d=d)
164	n/a	else:
165	n/a	d[obj] = prefix + trailer
166	n/a	return d
167	n/a
168	n/a	def tuple_name(param_list):
169	n/a	l = []
170	n/a	for obj in param_list:
171	n/a	if isinstance(obj, list):
172	n/a	l.append(tuple_name(obj))
173	n/a	else:
174	n/a	l.append(obj)
175	n/a	return "_".join(l)