Coverage for local/lib/python2.7/site-packages/sage/libs/ntl/ntl_ZZ_pContext.pyx : 53%

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

# Copyright (C) 2005 William Stein <wstein@gmail.com> 

# 

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

# 

# This code is distributed in the hope that it will be useful, 

# but WITHOUT ANY WARRANTY; without even the implied warranty of 

# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 

# General Public License for more details. 

# 

# The full text of the GPL is available at: 

# 

# http://www.gnu.org/licenses/ 

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

from __future__ import absolute_import 

include 'misc.pxi' 

include 'decl.pxi' 

import weakref 

from sage.rings.integer cimport Integer 

cdef class ntl_ZZ_pContext_class(object): 

def __init__(self, ntl_ZZ v): 

""" 

EXAMPLES: 

# You can construct contexts manually. 

sage: c = ntl.ZZ_pContext(11) 

sage: n1 = ntl.ZZ_p(12,c) 

sage: n1 

1 

# or You can construct contexts implicitly. 

sage: n2 = ntl.ZZ_p(12, 7) 

sage: n2 

5 

sage: ntl.ZZ_p(2,3)+ntl.ZZ_p(1,3) 

0 

sage: n2+n1 # Mismatched moduli: It will go BOOM! 

Traceback (most recent call last): 

... 

ValueError: You can not perform arithmetic with elements of different moduli. 

""" 

pass 

def __cinit__(self, ntl_ZZ v): 

self.x = ZZ_pContext_c(v.x) 

self.p = v 

self.p_bits = self.p._integer_().nbits() 

def __reduce__(self): 

""" 

EXAMPLES: 

sage: c = ntl.ZZ_pContext(13) 

sage: loads(dumps(c)) is c 

True 

""" 

return ntl_ZZ_pContext, (self.p,) 

def __repr__(self): 

""" 

Returns a print representation of self. 

EXAMPLES: 

sage: c = ntl.ZZ_pContext(7) 

sage: c 

NTL modulus 7 

""" 

return "NTL modulus %s"%(self.p) 

def __hash__(self): 

return hash(self.p) 

def modulus(self): 

""" 

Return the current modulus associated to this 

context. 

EXAMPLES: 

sage: c = ntl.ZZ_pContext(7) 

sage: c.modulus() 

7 

sage: c = ntl.ZZ_pContext(10^30) 

sage: type(c.modulus()) 

<type 'sage.rings.integer.Integer'> 

sage: c.modulus() == 10^30 

True 

""" 

return Integer(self.p) 

def restore(self): 

""" 

EXAMPLES: 

sage: c1 = ntl.ZZ_p(5,92) ; c2 = ntl.ZZ_p(7,92) 

sage: c1+c2 

12 

sage: d1 = ntl.ZZ_p(38,91) ; d2 = ntl.ZZ_p(3,91) 

sage: d1*d2 ## indirect doctest 

23 

""" 

self.restore_c() 

cdef void restore_c(self): 

self.x.restore() 

cdef class ntl_ZZ_pContext_factory(object): 

def __init__(self): 

self.context_dict = {} 

cdef ntl_ZZ_pContext_class make_c(self, ntl_ZZ v): 

""" 

Creates a new ZZ_pContext. 

INPUT: 

v -- an ntl_ZZ 

""" 

cdef ntl_ZZ_pContext_class context 

if v in self.context_dict: 

context = <ntl_ZZ_pContext_class> self.context_dict[v]() 

if context is not None: 

return context 

context = ntl_ZZ_pContext_class(v) 

self.context_dict[v] = weakref.ref(context) 

return context 

ZZ_pContext_factory = ntl_ZZ_pContext_factory() 

def ntl_ZZ_pContext( v ): 

""" 

Create a new ZZ_pContext. 

EXAMPLES: 

sage: c = ntl.ZZ_pContext(178) 

sage: n1 = ntl.ZZ_p(212,c) 

sage: n1 

34 

""" 

v = ntl_ZZ(v) 

if (v < ntl_ZZ(2)): 

raise ValueError("%s is not a valid modulus." % v) 

return (<ntl_ZZ_pContext_factory>ZZ_pContext_factory).make_c(v)