# repo.py - repository base classes for mercurial

#

# Copyright 2005, 2006 Matt Mackall <mpm@selenic.com>

# Copyright 2006 Vadim Gelfer <vadim.gelfer@gmail.com>

#

# This software may be used and distributed according to the terms

# of the GNU General Public License, incorporated herein by reference.

class RepoError(Exception):

    pass

class NoCapability(RepoError):

    pass

class repository(object):

    def capable(self, name):

        '''tell whether repo supports named capability.

        return False if not supported.

        if boolean capability, return True.

        if string capability, return string.'''

        if name in self.capabilities:

            return True

        name_eq = name + '='

        for cap in self.capabilities:

            if cap.startswith(name_eq):

                return cap[len(name_eq):]

        return False

    def requirecap(self, name, purpose):

        '''raise an exception if the given capability is not present'''

        if not self.capable(name):

            raise NoCapability(_('cannot %s; remote repository does not '

                                 'support the %r capability') %

                               (purpose, name))