hgext/alias.py

convert: separate trunk detection from branch layout detection

In some subversion repositories, trunk is present but no branches
are used. The current code is assuming that both trunk and branches
must exist before adding trunk's head to the heads list.

It's just better to separate the branch layout stuff from the trunk one.

# Copyright (C) 2007 Brendan Cully <[e-mail]>
# This file is published under the GNU GPL.

'''allow user-defined command aliases

To use, create entries in your hgrc of the form

[alias]
mycmd = cmd --args
'''

from mercurial.cmdutil import findcmd, UnknownCommand, AmbiguousCommand
from mercurial import commands

cmdtable = {}

class RecursiveCommand(Exception): pass

class lazycommand(object):
    '''defer command lookup until needed, so that extensions loaded
    after alias can be aliased'''
    def __init__(self, ui, name, target):
        self._ui = ui
        self._name = name
        self._target = target
        self._cmd = None

    def __len__(self):
        self._resolve()
        return len(self._cmd)

    def __getitem__(self, key):
        self._resolve()
        return self._cmd[key]

    def __iter__(self):
        self._resolve()
        return self._cmd.__iter__()

    def _resolve(self):
        if self._cmd is not None:
            return

        try:
            self._cmd = findcmd(self._ui, self._target, commands.table)[1]
            if self._cmd == self:
                raise RecursiveCommand()
            if self._target in commands.norepo.split(' '):
                commands.norepo += ' %s' % self._name
            return
        except UnknownCommand:
            msg = '*** [alias] %s: command %s is unknown' % \
                  (self._name, self._target)
        except AmbiguousCommand:
            msg = '*** [alias] %s: command %s is ambiguous' % \
                  (self._name, self._target)
        except RecursiveCommand:
            msg = '*** [alias] %s: circular dependency on %s' % \
                  (self._name, self._target)
        def nocmd(*args, **opts):
            self._ui.warn(msg + '\n')
            return 1
        nocmd.__doc__ = msg
        self._cmd = (nocmd, [], '')
        commands.norepo += ' %s' % self._name

def uisetup(ui):
    for cmd, target in ui.configitems('alias'):
        if not target:
            ui.warn('*** [alias] %s: no definition\n' % cmd)
            continue
        args = target.split(' ')
        tcmd = args.pop(0)
        if args:
            ui.setconfig('defaults', cmd, ' '.join(args))
        cmdtable[cmd] = lazycommand(ui, cmd, tcmd)