.. include:: ../../global.rst

.. _`bignum type`:

Bignum Type
===========

Bignums are "arbitrary" precision integers or floating point numbers
with a concept of exactness.

In principle, bignums allow arbitrary precision but most operations
involving bignums (including reading them in!) will "normalize" the
result to a value with up to 18 significant digits.

A bignum exponent is a signed 32-bit entity.

There is no support for special values such as "not a number" and
infinities.

Bignum Predicates
-----------------


.. _`bignum?`:

.. idio:function:: bignum? o


   test if `o` is a bignum				
   						
   :param o: object to test			
   :return: ``#t`` if `o` is a bignum, ``#f`` otherwise	


.. _`real?`:

.. idio:function:: real? n


   test if `n` is a real				
   						
   :param n: number to test			
   :type n: bignum					
   :return: ``#t`` if `n` is a real, ``#f`` otherwise	


.. _`exact?`:

.. idio:function:: exact? n


   test if `n` is exact				
   						
   :param n: number to test			
   :type n: bignum	or fixnum			
   :return: ``#t`` if `n` is exact, ``#f`` otherwise	


.. _`inexact?`:

.. idio:function:: inexact? n


   test if `n` is inexact				
   						
   :param n: number to test			
   :type n: bignum	or fixnum			
   :return: ``#t`` if `n` is inexact, ``#f`` otherwise	


Bignum Attributes
-----------------


.. _`mantissa`:

.. idio:function:: mantissa n


   return the mantissa of `n`			
   						
   :param n: number to find mantissa of		
   :type n: bignum	or fixnum			
   :return: mantissa of `n`			


.. _`exponent`:

.. idio:function:: exponent n


   return the exponent of `n`			
   						
   :param n: number to find exponent of		
   :type n: bignum					
   :return: exponent of `n`			


Bignum Converters
-----------------


.. _`exact->inexact`:

.. idio:function:: exact->inexact n


   return an inexact version of `n`		
   						
   :param n: number to convert			
   :type n: bignum	or fixnum			
   :return: inexact value of `n`			


.. _`inexact->exact`:

.. idio:function:: inexact->exact n


   return an exact version of `n`			
   						
   :param n: number to convert			
   :type n: bignum	or fixnum			
   :return: exact value of `n`			


Bignum Utilities
----------------


.. _`bignum-dump`:

.. idio:function:: bignum-dump n


   dump the bignum structure of `n` to	
   *stderr*				
   					
   :param n: number to dump		
   :type n: bignum				
   :return: ``#<unspec>``			




.. include:: ../../commit.rst