view mercurial/pushkey.py @ 24306:6ddc86eedc3b

style: kill ersatz if-else ternary operators

Although Python supports `X = Y if COND else Z`, this was only
introduced in Python 2.5. Since we have to support Python 2.4, it was
a very common thing to write instead `X = COND and Y or Z`, which is a
bit obscure at a glance. It requires some intricate knowledge of
Python to understand how to parse these one-liners.

We change instead all of these one-liners to 4-liners. This was
executed with the following perlism:

    find -name "*.py" -exec perl -pi -e 's,(\s*)([\.\w]+) = \(?(\S+)\s+and\s+(\S*)\)?\s+or\s+(\S*)$,$1if $3:\n$1    $2 = $4\n$1else:\n$1    $2 = $5,' {} \;

I tweaked the following cases from the automatic Perl output:

    prev = (parents and parents[0]) or nullid
    port = (use_ssl and 443 or 80)
    cwd = (pats and repo.getcwd()) or ''
    rename = fctx and webutil.renamelink(fctx) or []
    ctx = fctx and fctx or ctx
    self.base = (mapfile and os.path.dirname(mapfile)) or ''

I also added some newlines wherever they seemd appropriate for readability

There are probably a few ersatz ternary operators still in the code
somewhere, lurking away from the power of a simple regex.

# pushkey.py - dispatching for pushing and pulling keys
#
# Copyright 2010 Matt Mackall <[e-mail]>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

import bookmarks, phases, obsolete, encoding

def _nslist(repo):
    n = {}
    for k in _namespaces:
        n[k] = ""
    if not obsolete.isenabled(repo, obsolete.exchangeopt):
        n.pop('obsolete')
    return n

_namespaces = {"namespaces": (lambda *x: False, _nslist),
               "bookmarks": (bookmarks.pushbookmark, bookmarks.listbookmarks),
               "phases": (phases.pushphase, phases.listphases),
               "obsolete": (obsolete.pushmarker, obsolete.listmarkers),
              }

def register(namespace, pushkey, listkeys):
    _namespaces[namespace] = (pushkey, listkeys)

def _get(namespace):
    return _namespaces.get(namespace, (lambda *x: False, lambda *x: {}))

def push(repo, namespace, key, old, new):
    '''should succeed iff value was old'''
    pk = _get(namespace)[0]
    return pk(repo, key, old, new)

def list(repo, namespace):
    '''return a dict'''
    lk = _get(namespace)[1]
    return lk(repo)

encode = encoding.fromlocal

decode = encoding.tolocal

def encodekeys(keys):
    """encode the content of a pushkey namespace for exchange over the wire"""
    return '\n'.join(['%s\t%s' % (encode(k), encode(v)) for k, v in keys])

def decodekeys(data):
    """decode the content of a pushkey namespace from exchange over the wire"""
    result = {}
    for l in data.splitlines():
        k, v = l.split('\t')
        result[decode(k)] = decode(v)
    return result