Math::BigInt::Calc (Perl in a Nutshell, 2nd Edition)

8.144. Math::BigInt::Calc

Supports big integer calculations. Math::BigInt::Calc allows you to use library modules for core math routines. This module is shipped with the Perl 5.8 source kit.

If you've written a module that uses the same API as Math::BigInt, you can use Math::BigInt::Calc as follows:

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

Math::BigInt exports the following functions, which must be defined in your module so Math::BigInt can support it:

_new(string): Returns a reference to new object from reference to decimal string.
_zero(): Returns a new object with value 0.
_one(): Returns a new object with value 1.
_str(obj): Returns a reference to a string representing the object.
_num(obj): Returns a Perl integer or floating-point number. This may not necessarily be accurate, depending on machine-dependent, floating-point size limitations.
_add(obj, obj): Allows simple addition of two objects.
_mul(obj, obj): Allows multiplication of two objects.
_div(obj, obj): Implements division of the first object by the second. In a list context, div() returns result, remainder.
_sub(obj, obj): Implements simple subtraction of one object from another. A third, optional parameter indicates that the parameters are swapped.
_dec(obj): Decrements object by one.
_inc(obj): Increments object by one.
_acmp(obj, obj): The <=> operator for objects, which returns -1, 0, or 1.
_len(obj): Returns count of the decimal digits of the object.
_digit(obj, n): Returns the nth decimal digit of object.
_is_one(obj): Returns true if argument is 1.
_is_zero(obj): Returns true if the argument is 0.
_is_even(obj): Returns true if argument is even.
_is_odd(obj): Returns true if argument is odd.
_copy(): Returns a reference to a true copy of the object.
_check(obj): Checks whether the internal representation is still intact. Returns 0 for OK or an error message as a string.

The following functions are optional and can be defined if the underlying library can do them quickly. If undefined, Math::BigInt will use pure Perl fallback routines to emulate these. Note that falling back to Perl's routines will cause a performance hit.

_from_hex(string): Returns a reference to a new object from a reference to a hexadecimal string.
_from_bin(string): Returns a reference to a new object from a reference to a binary string.
_as_hex(string): Returns a reference to a scalar string containing the value as an unsigned hex string. _as_hex() prepends the 0x, although you must strip all leading zeros.
_as_bin(string): Similar to _as_hex(), except that it takes a binary string that contains only zeros and ones.
_rsft(obj, n, b): Shifts object (right) in base B by n digits. Returns undef on failure.
_lsft(obj, n, b): Shifts object in base b by n digits. Returns undef on failure.
_xor(obj1, obj2): Does an XOR of object 1 with object 2.
_and(obj1, obj2): Does an AND of object 1 with object 2.
_or(obj1, obj2): Does an OR of object 1 with object 2.
_mod(obj1, obj2): Returns remainder of division of the first object by the second object.
_sqrt(obj): Returns the square root of the object.
_fac(obj): Returns. factorial of object.
_pow(obj1, obj2): Returns object 1 to the power of object 2.
_gcd(obj1, obj2): Returns the greatest common divisor of two objects.
_zeros(obj): Returns the number of trailing decimal zeros.