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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.



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