121 lines
5.8 KiB
Python
121 lines
5.8 KiB
Python
u"""
|
|
Fixer for:
|
|
(a,)* *b (,c)* [,] = s
|
|
for (a,)* *b (,c)* [,] in d: ...
|
|
"""
|
|
|
|
from lib2to3 import fixer_base
|
|
from itertools import count
|
|
from lib2to3.fixer_util import (Assign, Comma, Call, Newline, Name,
|
|
Number, token, syms, Node, Leaf)
|
|
from libfuturize.fixer_util import indentation, suitify, commatize
|
|
# from libfuturize.fixer_util import Assign, Comma, Call, Newline, Name, Number, indentation, suitify, commatize, token, syms, Node, Leaf
|
|
|
|
def assignment_source(num_pre, num_post, LISTNAME, ITERNAME):
|
|
u"""
|
|
Accepts num_pre and num_post, which are counts of values
|
|
before and after the starg (not including the starg)
|
|
Returns a source fit for Assign() from fixer_util
|
|
"""
|
|
children = []
|
|
pre = unicode(num_pre)
|
|
post = unicode(num_post)
|
|
# This code builds the assignment source from lib2to3 tree primitives.
|
|
# It's not very readable, but it seems like the most correct way to do it.
|
|
if num_pre > 0:
|
|
pre_part = Node(syms.power, [Name(LISTNAME), Node(syms.trailer, [Leaf(token.LSQB, u"["), Node(syms.subscript, [Leaf(token.COLON, u":"), Number(pre)]), Leaf(token.RSQB, u"]")])])
|
|
children.append(pre_part)
|
|
children.append(Leaf(token.PLUS, u"+", prefix=u" "))
|
|
main_part = Node(syms.power, [Leaf(token.LSQB, u"[", prefix=u" "), Name(LISTNAME), Node(syms.trailer, [Leaf(token.LSQB, u"["), Node(syms.subscript, [Number(pre) if num_pre > 0 else Leaf(1, u""), Leaf(token.COLON, u":"), Node(syms.factor, [Leaf(token.MINUS, u"-"), Number(post)]) if num_post > 0 else Leaf(1, u"")]), Leaf(token.RSQB, u"]"), Leaf(token.RSQB, u"]")])])
|
|
children.append(main_part)
|
|
if num_post > 0:
|
|
children.append(Leaf(token.PLUS, u"+", prefix=u" "))
|
|
post_part = Node(syms.power, [Name(LISTNAME, prefix=u" "), Node(syms.trailer, [Leaf(token.LSQB, u"["), Node(syms.subscript, [Node(syms.factor, [Leaf(token.MINUS, u"-"), Number(post)]), Leaf(token.COLON, u":")]), Leaf(token.RSQB, u"]")])])
|
|
children.append(post_part)
|
|
source = Node(syms.arith_expr, children)
|
|
return source
|
|
|
|
class FixUnpacking(fixer_base.BaseFix):
|
|
|
|
PATTERN = u"""
|
|
expl=expr_stmt< testlist_star_expr<
|
|
pre=(any ',')*
|
|
star_expr< '*' name=NAME >
|
|
post=(',' any)* [','] > '=' source=any > |
|
|
impl=for_stmt< 'for' lst=exprlist<
|
|
pre=(any ',')*
|
|
star_expr< '*' name=NAME >
|
|
post=(',' any)* [','] > 'in' it=any ':' suite=any>"""
|
|
|
|
def fix_explicit_context(self, node, results):
|
|
pre, name, post, source = (results.get(n) for n in (u"pre", u"name", u"post", u"source"))
|
|
pre = [n.clone() for n in pre if n.type == token.NAME]
|
|
name.prefix = u" "
|
|
post = [n.clone() for n in post if n.type == token.NAME]
|
|
target = [n.clone() for n in commatize(pre + [name.clone()] + post)]
|
|
# to make the special-case fix for "*z, = ..." correct with the least
|
|
# amount of modification, make the left-side into a guaranteed tuple
|
|
target.append(Comma())
|
|
source.prefix = u""
|
|
setup_line = Assign(Name(self.LISTNAME), Call(Name(u"list"), [source.clone()]))
|
|
power_line = Assign(target, assignment_source(len(pre), len(post), self.LISTNAME, self.ITERNAME))
|
|
return setup_line, power_line
|
|
|
|
def fix_implicit_context(self, node, results):
|
|
u"""
|
|
Only example of the implicit context is
|
|
a for loop, so only fix that.
|
|
"""
|
|
pre, name, post, it = (results.get(n) for n in (u"pre", u"name", u"post", u"it"))
|
|
pre = [n.clone() for n in pre if n.type == token.NAME]
|
|
name.prefix = u" "
|
|
post = [n.clone() for n in post if n.type == token.NAME]
|
|
target = [n.clone() for n in commatize(pre + [name.clone()] + post)]
|
|
# to make the special-case fix for "*z, = ..." correct with the least
|
|
# amount of modification, make the left-side into a guaranteed tuple
|
|
target.append(Comma())
|
|
source = it.clone()
|
|
source.prefix = u""
|
|
setup_line = Assign(Name(self.LISTNAME), Call(Name(u"list"), [Name(self.ITERNAME)]))
|
|
power_line = Assign(target, assignment_source(len(pre), len(post), self.LISTNAME, self.ITERNAME))
|
|
return setup_line, power_line
|
|
|
|
def transform(self, node, results):
|
|
u"""
|
|
a,b,c,d,e,f,*g,h,i = range(100) changes to
|
|
_3to2list = list(range(100))
|
|
a,b,c,d,e,f,g,h,i, = _3to2list[:6] + [_3to2list[6:-2]] + _3to2list[-2:]
|
|
|
|
and
|
|
|
|
for a,b,*c,d,e in iter_of_iters: do_stuff changes to
|
|
for _3to2iter in iter_of_iters:
|
|
_3to2list = list(_3to2iter)
|
|
a,b,c,d,e, = _3to2list[:2] + [_3to2list[2:-2]] + _3to2list[-2:]
|
|
do_stuff
|
|
"""
|
|
self.LISTNAME = self.new_name(u"_3to2list")
|
|
self.ITERNAME = self.new_name(u"_3to2iter")
|
|
expl, impl = results.get(u"expl"), results.get(u"impl")
|
|
if expl is not None:
|
|
setup_line, power_line = self.fix_explicit_context(node, results)
|
|
setup_line.prefix = expl.prefix
|
|
power_line.prefix = indentation(expl.parent)
|
|
setup_line.append_child(Newline())
|
|
parent = node.parent
|
|
i = node.remove()
|
|
parent.insert_child(i, power_line)
|
|
parent.insert_child(i, setup_line)
|
|
elif impl is not None:
|
|
setup_line, power_line = self.fix_implicit_context(node, results)
|
|
suitify(node)
|
|
suite = [k for k in node.children if k.type == syms.suite][0]
|
|
setup_line.prefix = u""
|
|
power_line.prefix = suite.children[1].value
|
|
suite.children[2].prefix = indentation(suite.children[2])
|
|
suite.insert_child(2, Newline())
|
|
suite.insert_child(2, power_line)
|
|
suite.insert_child(2, Newline())
|
|
suite.insert_child(2, setup_line)
|
|
results.get(u"lst").replace(Name(self.ITERNAME, prefix=u" "))
|