bigint(3)
NAME
bigint - Transparent big integer support for Perl
SYNOPSIS
use bignt; $x = 2 + 4.5,"0; # BigInt 6 print 2 ** 512; # really is what you think it is
DESCRIPTION
All operators (including basic math operations) are over
loaded. Integer constants are created as proper BigInts.
Floating point constants are truncated to integer. All
results are also trunctaed.
OPTIONS
bigint recognizes some options that can be passed while
loading it via use. The options can (currently) be either
a single letter form, or the long form. The following
options exist:
- a or accuracy
- This sets the accuracy for all math operations. The
argument must be greater than or equal to zero. See
Math::BigInt's bround() function for details.
perl -Mbigint=a,2 -le 'print 12345+1' - p or precision
- This sets the precision for all math operations. The
argument can be any integer. Negative values mean a
fixed number of digits after the dot, and are
<B>ignored</B> since all operations happen in integer
space. A positive value rounds to this digit left from
the dot. 0 or 1 mean round to integer and are ignore
like negative values. - See Math::BigInt's bfround() function for details.
perl -Mbignum=p,5 -le 'print 123456789+123' - t or trace
- This enables a trace mode and is primarily for debugging
bigint or Math::BigInt. - l or lib
- Load a different math lib, see "MATH LIBRARY".
perl -Mbigint=l,GMP -e 'print 2 ** 512' - Currently there is no way to specify more than one
library on the command line. This will be hopefully
fixed soon ;) - v or version
- This prints out the name and version of all modules used
and then exits.
perl -Mbigint=v -e '' - MATH LIBRARY
- Math with the numbers is done (by default) by a module
called Math::BigInt::Calc. This is equivalent to saying:
use bigint lib => 'Calc';- You can change this by using:
use bigint lib => 'BitVect';- The following would first try to find Math::BigInt::Foo,
then Math::BigInt::Bar, and when this also fails, revert
to Math::BigInt::Calc:
use bigint lib => 'Foo,Math::BigInt::Bar';- Please see respective module documentation for further
details. - INTERNAL FORMAT
- The numbers are stored as objects, and their internals
might change at anytime, especially between math opera
tions. The objects also might belong to different classes,
like Math::BigInt, or Math::BigInt::Lite. Mixing them
together, even with normal scalars is not extraordinary,
but normal and expected. - You should not depend on the internal format, all accesses
must go through accessor methods. E.g. looking at
$x->{sign} is not a bright idea since there is no guaranty
that the object in question has such a hash key, nor is a
hash underneath at all. - SIGN
- The sign is either '+', '-', 'NaN', '+inf' or '-inf' and
stored seperately. You can access it with the sign()
method. - A sign of 'NaN' is used to represent the result when input
arguments are not numbers or as a result of 0/0. '+inf'
and '-inf' represent plus respectively minus infinity. You
will get '+inf' when dividing a positive number by 0, and
'-inf' when dividing any negative number by 0. - METHODS
- Since all numbers are now objects, you can use all func
tions that are part of the BigInt API. You can only use
the bxxx() notation, and not the fxxx() notation, though.
MODULES USED
"bigint" is just a thin wrapper around various modules of
the Math::BigInt family. Think of it as the head of the
family, who runs the shop, and orders the others to do the
work.
- The following modules are currently used by bigint:
- Math::BigInt::Lite (for speed, and only if it
- is loadable)
Math::BigInt
EXAMPLES
- Some cool command line examples to impress the Python
crowd ;) You might want to compare them to the results
under -Mbignum or -Mbigrat: - perl -Mbigint -le 'print sqrt(33)'
perl -Mbigint -le 'print 2*255'
perl -Mbigint -le 'print 4.5+2*255'
perl -Mbigint -le 'print 3/7 + 5/7 + 8/3'
perl -Mbigint -le 'print 123->is_odd()'
perl -Mbigint -le 'print log(2)'
perl -Mbigint -le 'print 2 ** 0.5'
perl -Mbigint=a,65 -le 'print 2 ** 0.2'
LICENSE
This program is free software; you may redistribute it
and/or modify it under the same terms as Perl itself.
SEE ALSO
Especially bigrat as in "perl -Mbigrat -le 'print
1/3+1/4'" and bignum as in "perl -Mbignum -le 'print
sqrt(2)'".
Math::BigInt, Math::BigRat and Math::Big as well as
Math::BigInt::BitVect, Math::BigInt::Pari and Math::Big
Int::GMP.
AUTHORS
- (C) by Tels <http://bloodgate.com/> in early 2002.