Math::BigInt::Calc(3pm)

1Math::BigInt::Calc(3pm)Perl Programmers Reference GuideMath::BigInt::Calc(3pm)
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NAME

6       Math::BigInt::Calc - Pure Perl module to support Math::BigInt
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SYNOPSIS

9       Provides support for big integer calculations. Not intended to be used
10       by other modules. Other modules which sport the same functions can also
11       be used to support Math::BigInt, like Math::BigInt::GMP or Math::Big‐
12       Int::Pari.
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DESCRIPTION

15       In order to allow for multiple big integer libraries, Math::BigInt was
16       rewritten to use library modules for core math routines. Any module
17       which follows the same API as this can be used instead by using the
18       following:
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20               use Math::BigInt lib => 'libname';
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22       'libname' is either the long name ('Math::BigInt::Pari'), or only the
23       short version like 'Pari'.
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STORAGE

METHODS

27       The following functions MUST be defined in order to support the use by
28       Math::BigInt v1.70 or later:
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30               api_version()   return API version, minimum 1 for v1.70
31               _new(string)    return ref to new object from ref to decimal string
32               _zero()         return a new object with value 0
33               _one()          return a new object with value 1
34               _two()          return a new object with value 2
35               _ten()          return a new object with value 10
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37               _str(obj)       return ref to a string representing the object
38               _num(obj)       returns a Perl integer/floating point number
39                               NOTE: because of Perl numeric notation defaults,
40                               the _num'ified obj may lose accuracy due to
41                               machine-dependend floating point size limitations
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43               _add(obj,obj)   Simple addition of two objects
44               _mul(obj,obj)   Multiplication of two objects
45               _div(obj,obj)   Division of the 1st object by the 2nd
46                               In list context, returns (result,remainder).
47                               NOTE: this is integer math, so no
48                               fractional part will be returned.
49                               The second operand will be not be 0, so no need to
50                               check for that.
51               _sub(obj,obj)   Simple subtraction of 1 object from another
52                               a third, optional parameter indicates that the params
53                               are swapped. In this case, the first param needs to
54                               be preserved, while you can destroy the second.
55                               sub (x,y,1) => return x - y and keep x intact!
56               _dec(obj)       decrement object by one (input is garant. to be > 0)
57               _inc(obj)       increment object by one
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59               _acmp(obj,obj)  <=> operator for objects (return -1, 0 or 1)
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61               _len(obj)       returns count of the decimal digits of the object
62               _digit(obj,n)   returns the n'th decimal digit of object
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64               _is_one(obj)    return true if argument is 1
65               _is_two(obj)    return true if argument is 2
66               _is_ten(obj)    return true if argument is 10
67               _is_zero(obj)   return true if argument is 0
68               _is_even(obj)   return true if argument is even (0,2,4,6..)
69               _is_odd(obj)    return true if argument is odd (1,3,5,7..)
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71               _copy           return a ref to a true copy of the object
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73               _check(obj)     check whether internal representation is still intact
74                               return 0 for ok, otherwise error message as string
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76               _from_hex(str)  return ref to new object from ref to hexadecimal string
77               _from_bin(str)  return ref to new object from ref to binary string
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79               _as_hex(str)    return string containing the value as
80                               unsigned hex string, with the '0x' prepended.
81                               Leading zeros must be stripped.
82               _as_bin(str)    Like as_hex, only as binary string containing only
83                               zeros and ones. Leading zeros must be stripped and a
84                               '0b' must be prepended.
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86               _rsft(obj,N,B)  shift object in base B by N 'digits' right
87               _lsft(obj,N,B)  shift object in base B by N 'digits' left
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89               _xor(obj1,obj2) XOR (bit-wise) object 1 with object 2
90                               Note: XOR, AND and OR pad with zeros if size mismatches
91               _and(obj1,obj2) AND (bit-wise) object 1 with object 2
92               _or(obj1,obj2)  OR (bit-wise) object 1 with object 2
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94               _mod(obj,obj)   Return remainder of div of the 1st by the 2nd object
95               _sqrt(obj)      return the square root of object (truncated to int)
96               _root(obj)      return the n'th (n >= 3) root of obj (truncated to int)
97               _fac(obj)       return factorial of object 1 (1*2*3*4..)
98               _pow(obj,obj)   return object 1 to the power of object 2
99                               return undef for NaN
100               _zeros(obj)     return number of trailing decimal zeros
101               _modinv         return inverse modulus
102               _modpow         return modulus of power ($x ** $y) % $z
103               _log_int(X,N)   calculate integer log() of X in base N
104                               X >= 0, N >= 0 (return undef for NaN)
105                               returns (RESULT, EXACT) where EXACT is:
106                                1     : result is exactly RESULT
107                                0     : result was truncated to RESULT
108                                undef : unknown whether result is exactly RESULT
109               _gcd(obj,obj)   return Greatest Common Divisor of two objects
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111       The following functions are optional, and can be defined if the under‐
112       lying lib has a fast way to do them. If undefined, Math::BigInt will
113       use pure Perl (hence slow) fallback routines to emulate these:
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115               _signed_or
116               _signed_and
117               _signed_xor
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119       Input strings come in as unsigned but with prefix (i.e. as '123',
120       '0xabc' or '0b1101').
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122       So the library needs only to deal with unsigned big integers. Testing
123       of input parameter validity is done by the caller, so you need not
124       worry about underflow (f.i. in "_sub()", "_dec()") nor about division
125       by zero or similar cases.
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127       The first parameter can be modified, that includes the possibility that
128       you return a reference to a completely different object instead.
129       Although keeping the reference and just changing it's contents is pref‐
130       ered over creating and returning a different reference.
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132       Return values are always references to objects, strings, or true/false
133       for comparisation routines.
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WRAP YOUR OWN

136       If you want to port your own favourite c-lib for big numbers to the
137       Math::BigInt interface, you can take any of the already existing mod‐
138       ules as a rough guideline. You should really wrap up the latest BigInt
139       and BigFloat testsuites with your module, and replace in them any of
140       the following:
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142               use Math::BigInt;
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144       by this:
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146               use Math::BigInt lib => 'yourlib';
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148       This way you ensure that your library really works 100% within
149       Math::BigInt.
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LICENSE

152       This program is free software; you may redistribute it and/or modify it
153       under the same terms as Perl itself.
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AUTHORS

156       Original math code by Mark Biggar, rewritten by Tels <http://blood‐
157       gate.com/> in late 2000.  Seperated from BigInt and shaped API with the
158       help of John Peacock.
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160       Fixed, speed-up, streamlined and enhanced by Tels 2001 - 2005.
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