"""Fixer that changes bytes % whatever to a function that actually formats
it."""
from lib2to3 import fixer_base
from lib2to3.fixer_util import is_tuple, Call, Comma, Name, touch_import
# XXX: Implementing a blacklist in 2to3 turned out to be more troublesome than
# blacklisting some modules inside the fixers. So, this is what I came with.
blacklist = ['mercurial/demandimport.py',
'mercurial/py3kcompat.py',
'mercurial/i18n.py',
]
def isnumberremainder(formatstr, data):
try:
if data.value.isdigit():
return True
except AttributeError:
return False
class FixBytesmod(fixer_base.BaseFix):
# XXX: There's one case (I suppose) I can't handle: when a remainder
# operation like foo % bar is performed, I can't really know what the
# contents of foo and bar are. I believe the best approach is to "correct"
# the to-be-converted code and let bytesformatter handle that case in
# runtime.
PATTERN = '''
term< formatstr=STRING '%' data=STRING > |
term< formatstr=STRING '%' data=atom > |
term< formatstr=NAME '%' data=any > |
term< formatstr=any '%' data=any >
'''
def transform(self, node, results):
if self.filename in blacklist:
return
elif self.filename == 'mercurial/util.py':
touch_import('.', 'py3kcompat', node=node)
formatstr = results['formatstr'].clone()
data = results['data'].clone()
formatstr.prefix = '' # remove spaces from start
if isnumberremainder(formatstr, data):
return
# We have two possibilities:
# 1- An identifier or name is passed, it is going to be a leaf, thus, we
# just need to copy its value as an argument to the formatter;
# 2- A tuple is explicitly passed. In this case, we're gonna explode it
# to pass to the formatter
# TODO: Check for normal strings. They don't need to be translated
if is_tuple(data):
args = [formatstr, Comma().clone()] + \
[c.clone() for c in data.children[:]]
else:
args = [formatstr, Comma().clone(), data]
call = Call(Name('bytesformatter', prefix = ' '), args)
return call