Math::BigInt::Calc(3)  Perl Programmers Reference Guide  Math::BigInt::Calc(3)

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

       Provides support for big integer calculations. Not intended to be used
       by other modules. Other modules which sport the same functions can also
       be used to support Math::BigInt, like Math::BigInt::GMP or Math::Big-

       In order to allow for multiple big integer libraries, Math::BigInt was
       rewritten to use library modules for core math routines. Any module
       which follows the same API as this can be used instead by using the

               use Math::BigInt lib => 'libname';

       'libname' is either the long name ('Math::BigInt::Pari'), or only the
       short version like 'Pari'.

       The following functions MUST be defined in order to support the use by
       Math::BigInt v1.70 or later:

               api_version()   return API version, minimum 1 for v1.70
               _new(string)    return ref to new object from ref to decimal string
               _zero()         return a new object with value 0
               _one()          return a new object with value 1
               _two()          return a new object with value 2
               _ten()          return a new object with value 10

               _str(obj)       return ref to a string representing the object
               _num(obj)       returns a Perl integer/floating point number
                               NOTE: because of Perl numeric notation defaults,
                               the _num'ified obj may lose accuracy due to
                               machine-dependend floating point size limitations

               _add(obj,obj)   Simple addition of two objects
               _mul(obj,obj)   Multiplication of two objects
               _div(obj,obj)   Division of the 1st object by the 2nd
                               In list context, returns (result,remainder).
                               NOTE: this is integer math, so no
                               fractional part will be returned.
                               The second operand will be not be 0, so no need to
                               check for that.
               _sub(obj,obj)   Simple subtraction of 1 object from another
                               a third, optional parameter indicates that the params
                               are swapped. In this case, the first param needs to
                               be preserved, while you can destroy the second.
                               sub (x,y,1) => return x - y and keep x intact!
               _dec(obj)       decrement object by one (input is garant. to be > 0)
               _inc(obj)       increment object by one

               _acmp(obj,obj)  <=> operator for objects (return -1, 0 or 1)

               _len(obj)       returns count of the decimal digits of the object
               _digit(obj,n)   returns the n'th decimal digit of object

               _is_one(obj)    return true if argument is 1
               _is_two(obj)    return true if argument is 2
               _is_ten(obj)    return true if argument is 10
               _is_zero(obj)   return true if argument is 0
               _is_even(obj)   return true if argument is even (0,2,4,6..)
               _is_odd(obj)    return true if argument is odd (1,3,5,7..)

               _copy           return a ref to a true copy of the object

               _check(obj)     check whether internal representation is still intact
                               return 0 for ok, otherwise error message as string

               _from_hex(str)  return ref to new object from ref to hexadecimal string
               _from_bin(str)  return ref to new object from ref to binary string

               _as_hex(str)    return string containing the value as
                               unsigned hex string, with the '0x' prepended.
                               Leading zeros must be stripped.
               _as_bin(str)    Like as_hex, only as binary string containing only
                               zeros and ones. Leading zeros must be stripped and a
                               '0b' must be prepended.

               _rsft(obj,N,B)  shift object in base B by N 'digits' right
               _lsft(obj,N,B)  shift object in base B by N 'digits' left

               _xor(obj1,obj2) XOR (bit-wise) object 1 with object 2
                               Note: XOR, AND and OR pad with zeros if size mismatches
               _and(obj1,obj2) AND (bit-wise) object 1 with object 2
               _or(obj1,obj2)  OR (bit-wise) object 1 with object 2

               _mod(obj,obj)   Return remainder of div of the 1st by the 2nd object
               _sqrt(obj)      return the square root of object (truncated to int)
               _root(obj)      return the n'th (n >= 3) root of obj (truncated to int)
               _fac(obj)       return factorial of object 1 (1*2*3*4..)
               _pow(obj,obj)   return object 1 to the power of object 2
                               return undef for NaN
               _zeros(obj)     return number of trailing decimal zeros
               _modinv         return inverse modulus
               _modpow         return modulus of power ($x ** $y) % $z
               _log_int(X,N)   calculate integer log() of X in base N
                               X >= 0, N >= 0 (return undef for NaN)
                               returns (RESULT, EXACT) where EXACT is:
                                1     : result is exactly RESULT
                                0     : result was truncated to RESULT
                                undef : unknown whether result is exactly RESULT
               _gcd(obj,obj)   return Greatest Common Divisor of two objects

       The following functions are optional, and can be defined if the under-
       lying lib has a fast way to do them. If undefined, Math::BigInt will
       use pure Perl (hence slow) fallback routines to emulate these:


       Input strings come in as unsigned but with prefix (i.e. as '123',
       '0xabc' or '0b1101').

       So the library needs only to deal with unsigned big integers. Testing
       of input parameter validity is done by the caller, so you need not
       worry about underflow (f.i. in "_sub()", "_dec()") nor about division
       by zero or similar cases.

       The first parameter can be modified, that includes the possibility that
       you return a reference to a completely different object instead.
       Although keeping the reference and just changing it's contents is pref-
       ered over creating and returning a different reference.

       Return values are always references to objects, strings, or true/false
       for comparisation routines.

       If you want to port your own favourite c-lib for big numbers to the
       Math::BigInt interface, you can take any of the already existing mod-
       ules as a rough guideline. You should really wrap up the latest BigInt
       and BigFloat testsuites with your module, and replace in them any of
       the following:

               use Math::BigInt;

       by this:

               use Math::BigInt lib => 'yourlib';

       This way you ensure that your library really works 100% within

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

       Original math code by Mark Biggar, rewritten by Tels <http://blood-> in late 2000.  Seperated from BigInt and shaped API with the
       help of John Peacock.  Fixed, sped-up and enhanced by Tels 2001-2003.  Further streamlining (api_version 1)
       by Tels 2004.

       Math::BigInt, Math::BigFloat, Math::BigInt::BitVect, Math::BigInt::GMP,
       Math::BigInt::FastCalc and Math::BigInt::Pari.

perl v5.8.6                       2001-09-21             Math::BigInt::Calc(3)