Book a Demo!
CoCalc Logo Icon
StoreFeaturesDocsShareSupportNewsAboutPoliciesSign UpSign In
sagemath
GitHub Repository: sagemath/sagelib
 Path: blob/master/sage/libs/ntl/ntl_lzz_pContext.pyx
4107 views
1
#*****************************************************************************

2
#       Copyright (C) 2005 William Stein <[email protected]>

3
#

4
#  Distributed under the terms of the GNU General Public License (GPL)

5
#

6
#    This code is distributed in the hope that it will be useful,

7
#    but WITHOUT ANY WARRANTY; without even the implied warranty of

8
#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

9
#    General Public License for more details.

10
#

11
#  The full text of the GPL is available at:

12
#

13
#                  http://www.gnu.org/licenses/

14
#*****************************************************************************

15


16
include "../../ext/interrupt.pxi"

17
include "../../ext/stdsage.pxi"

18
include 'misc.pxi'

19
include 'decl.pxi'

20


21
from sage.rings.integer import Integer

22
from sage.rings.integer cimport Integer

23


24
zz_pContextDict = {}

25


26
cdef class ntl_zz_pContext_class:

27
    def __init__(self, long v):

28
        """

29
        EXAMPLES:

30
            # You can construct contexts manually.

31
            sage: c = ntl.zz_pContext(11)

32
            sage: n1 = ntl.zz_p(12,c)

33
            sage: n1

34
            1

35


36
            # or You can construct contexts implicitly.

37
            sage: n2=ntl.zz_p(12, 7)

38
            sage: n2

39
            5

40
            sage: ntl.zz_p(2,3)+ntl.zz_p(1,3)

41
            0

42
            sage: n2+n1  # Mismatched moduli:  It will go BOOM!

43
            Traceback (most recent call last):

44
            ...

45
            ValueError: arithmetic operands must have the same modulus.

46
        """

47
        pass

48
        

49
    def __cinit__(self, long v):

50
        if v > NTL_SP_BOUND:

51
            raise ValueError, "Modulus (=%s) is too big"%v

52
        zz_pContext_construct_long(&self.x, v)

53
        zz_pContextDict[repr(v)] = self

54
        self.p = v

55


56
    def __dealloc__(self):

57
        zz_pContext_destruct(&self.x)

58


59
    def __reduce__(self):

60
        """

61
        sage: c=ntl.zz_pContext(13)

62
        sage: loads(dumps(c)) is c

63
        True

64
        """

65
        return ntl_zz_pContext, (self.p,)

66


67
    def modulus(self):

68
        """

69
        Print the modulus for self.

70


71
        EXAMPLES:

72
            sage: c1 = ntl.zz_pContext(36)

73
            sage: c1.modulus()

74
            36

75
        """

76
        return self.p

77


78
    def restore(self):

79
        """

80
        Restore a zz_pContext.

81


82
        EXAMPLES:

83
            sage: c = ntl.zz_pContext(5)

84
            sage: m = ntl.zz_p(4,7)

85
            sage: c.restore()

86
        """

87
        self.restore_c()

88


89
    cdef void restore_c(self):

90
        """

91
        Actual code for the above.

92
        

93
        EXAMPLES:

94
            sage: n = ntl.zz_p(3,5)

95
            sage: m = ntl.zz_p(4,7)

96
            sage: n*n ## indirect doctest

97
            4

98
        """

99
        zz_pContext_restore(&self.x)

100


101
def ntl_zz_pContext( v ):

102
    """

103
    Creation function for a zz_p context.

104


105
    EXAMPLES:

106
        sage: f = ntl.zz_pContext(26)

107
        sage: f = ntl.zz_pContext(10^100)

108
        Traceback (most recent call last):

109
        ...

110
        ValueError: Modulus (=10000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000) is too big

111
    """

112
    if v > NTL_SP_BOUND:

113
        raise ValueError, "Modulus (=%s) is too big"%v

114
    if PY_TYPE_CHECK(v, Integer):

115
        v = mpz_get_si((<Integer>v).value)

116
    try:

117
        return zz_pContextDict[repr(v)]

118
    except KeyError:

119
        return ntl_zz_pContext_class(v)

120


121