Coverage for local/lib/python2.7/site-packages/sage/rings/integer_fake.pxd : 80%

""" 

Fake Integer interface 

This exists to solve the problem of cyclic imports involving the 

``Integer`` class. The problem is that ``Integer`` depends on the 

coercion model and the coercion model depends on ``Integer``. 

Therefore, this should only be used to implement things at a lower 

level than ``Integer``, such as the coercion model. 

This provides two functions: 

- ``Integer_AS_MPZ(x)``: access the value of the Integer ``x`` as GMP 

``mpz_t``. 

- ``is_Integer(x)``: is ``x`` an Integer? 

TESTS:: 

sage: cython(''' 

....: from sage.rings.integer_fake cimport Integer_AS_MPZ, is_Integer 

....: from sage.rings.integer cimport Integer 

....: cdef Integer x = Integer(123456789) 

....: assert is_Integer(x) 

....: assert Integer_AS_MPZ(x) is x.value 

....: ''') 

""" 

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

# Copyright (C) 2017 Jeroen Demeyer <J.Demeyer@UGent.be> 

# 

# This program is free software: you can redistribute it and/or modify 

# it under the terms of the GNU General Public License as published by 

# the Free Software Foundation, either version 2 of the License, or 

# (at your option) any later version. 

# http://www.gnu.org/licenses/ 

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

from cpython.ref cimport PyTypeObject, Py_TYPE 

from sage.libs.gmp.types cimport mpz_ptr 

cdef extern from "integer_fake.h": 

PyTypeObject* Integer # Imported as needed 

mpz_ptr Integer_AS_MPZ(x) 

bint unlikely(bint c) # Defined by Cython 

cdef inline bint is_Integer(x): 

global Integer 

if unlikely(Integer is NULL): 

import sage.rings.integer 

Integer = <PyTypeObject*>sage.rings.integer.Integer 

return Py_TYPE(x) is Integer