Coverage for local/lib/python2.7/site-packages/sage/groups/group_homset.py : 56%

""" 

Set of homomorphisms between two groups. 

""" 

#***************************************************************************** 

# Copyright (C) 2006 William Stein <wstein@gmail.com> 

# 

# Distributed under the terms of the GNU General Public License (GPL) 

# 

# http://www.gnu.org/licenses/ 

#***************************************************************************** 

from sage.categories.all import HomsetWithBase, Groups 

import sage.rings.integer_ring 

def is_GroupHomset(H): 

return isinstance(H, GroupHomset_generic) 

def GroupHomset(G, H): 

return RingHomset_generic(G, H) 

class GroupHomset_generic(HomsetWithBase): 

""" 

This class will not work since morphism.GroupHomomorphism_coercion 

is undefined and morphism.GroupHomomorphism_im_gens is undefined. 

""" 

def __init__(self, G, H): 

HomsetWithBase.__init__(self, G, H, Groups(), sage.rings.integer_ringer.ZZ) 

def _repr_(self): 

return "Set of Homomorphisms from %s to %s"%(self.domain(), self.codomain()) 

def __call__(self, im_gens, check=True): 

""" 

EXAMPLES: 

""" 

try: 

return morphism.GroupHomomorphism_im_gens(self, im_gens, check=check) 

except (NotImplementedError, ValueError) as err: 

raise TypeError("images (=%s) do not define a valid homomorphism"%im_gens) 

def natural_map(self): 

return morphism.GroupHomomorphism_coercion(self)