package bignum; require 5.005; $VERSION = '0.11'; use Exporter; @ISA = qw( Exporter ); @EXPORT_OK = qw( ); use strict; ############################################################################## # These are all alike, and thus faked by AUTOLOAD my @faked = qw/round_mode accuracy precision div_scale/; use vars qw/$VERSION $AUTOLOAD $_lite/; # _lite for testsuite sub AUTOLOAD { my $name = $AUTOLOAD; $name =~ s/.*:://; # split package no strict 'refs'; foreach my $n (@faked) { if ($n eq $name) { *{"bignum::$name"} = sub { my $self = shift; no strict 'refs'; if (defined $_[0]) { Math::BigInt->$name($_[0]); Math::BigFloat->$name($_[0]); } return Math::BigInt->$name(); }; return &$name; } } # delayed load of Carp and avoid recursion require Carp; Carp::croak ("Can't call bignum\-\>$name, not a valid method"); } sub upgrade { my $self = shift; no strict 'refs'; # if (defined $_[0]) # { # $Math::BigInt::upgrade = $_[0]; # $Math::BigFloat::upgrade = $_[0]; # } return $Math::BigInt::upgrade; } sub import { my $self = shift; # some defaults my $lib = 'Calc'; my $upgrade = 'Math::BigFloat'; my $downgrade = 'Math::BigInt'; my @import = ( ':constant' ); # drive it w/ constant my @a = @_; my $l = scalar @_; my $j = 0; my ($ver,$trace); # version? trace? my ($a,$p); # accuracy, precision for ( my $i = 0; $i < $l ; $i++,$j++ ) { if ($_[$i] eq 'upgrade') { # this causes upgrading $upgrade = $_[$i+1]; # or undef to disable my $s = 2; $s = 1 if @a-$j < 2; # avoid "can not modify non-existant..." splice @a, $j, $s; $j -= $s; $i++; } elsif ($_[$i] eq 'downgrade') { # this causes downgrading $downgrade = $_[$i+1]; # or undef to disable my $s = 2; $s = 1 if @a-$j < 2; # avoid "can not modify non-existant..." splice @a, $j, $s; $j -= $s; $i++; } elsif ($_[$i] =~ /^(l|lib)$/) { # this causes a different low lib to take care... $lib = $_[$i+1] || ''; my $s = 2; $s = 1 if @a-$j < 2; # avoid "can not modify non-existant..." splice @a, $j, $s; $j -= $s; $i++; } elsif ($_[$i] =~ /^(a|accuracy)$/) { $a = $_[$i+1]; my $s = 2; $s = 1 if @a-$j < 2; # avoid "can not modify non-existant..." splice @a, $j, $s; $j -= $s; $i++; } elsif ($_[$i] =~ /^(p|precision)$/) { $p = $_[$i+1]; my $s = 2; $s = 1 if @a-$j < 2; # avoid "can not modify non-existant..." splice @a, $j, $s; $j -= $s; $i++; } elsif ($_[$i] =~ /^(v|version)$/) { $ver = 1; splice @a, $j, 1; $j --; } elsif ($_[$i] =~ /^(t|trace)$/) { $trace = 1; splice @a, $j, 1; $j --; } else { die "unknown option $_[$i]"; } } my $class; $_lite = 0; # using M::BI::L ? if ($trace) { require Math::BigInt::Trace; $class = 'Math::BigInt::Trace'; $upgrade = 'Math::BigFloat::Trace'; } else { # see if we can find Math::BigInt::Lite if (!defined $a && !defined $p) # rounding won't work to well { eval 'require Math::BigInt::Lite;'; if ($@ eq '') { @import = ( ); # :constant in Lite, not MBI Math::BigInt::Lite->import( ':constant' ); $_lite= 1; # signal okay } } require Math::BigInt if $_lite == 0; # not already loaded? $class = 'Math::BigInt'; # regardless of MBIL or not } # Math::BigInt::Trace or plain Math::BigInt $class->import(@import, upgrade => $upgrade, lib => $lib); if ($trace) { require Math::BigFloat::Trace; $class = 'Math::BigFloat::Trace'; $downgrade = 'Math::BigInt::Trace'; } else { require Math::BigFloat; $class = 'Math::BigFloat'; } $class->import(':constant','downgrade',$downgrade); bignum->accuracy($a) if defined $a; bignum->precision($p) if defined $p; if ($ver) { print "bignum\t\t\t v$VERSION\n"; print "Math::BigInt::Lite\t v$Math::BigInt::Lite::VERSION\n" if $_lite; print "Math::BigInt\t\t v$Math::BigInt::VERSION"; my $config = Math::BigInt->config(); print " lib => $config->{lib} v$config->{lib_version}\n"; print "Math::BigFloat\t\t v$Math::BigFloat::VERSION\n"; exit; } } 1; __END__ =head1 NAME bignum - Transparent BigNumber support for Perl =head1 SYNOPSIS use bignum; $x = 2 + 4.5,"\n"; # BigFloat 6.5 print 2 ** 512 * 0.1; # really is what you think it is =head1 DESCRIPTION All operators (including basic math operations) are overloaded. Integer and floating-point constants are created as proper BigInts or BigFloats, respectively. =head2 OPTIONS bignum 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: =over 2 =item 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 -Mbignum=a,50 -le 'print sqrt(20)' =item 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, while a positive value rounds to this digit left from the dot. 0 or 1 mean round to integer. See Math::BigInt's bfround() function for details. perl -Mbignum=p,-50 -le 'print sqrt(20)' =item t or trace This enables a trace mode and is primarily for debugging bignum or Math::BigInt/Math::BigFloat. =item l or lib Load a different math lib, see L. perl -Mbignum=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 ;) =item v or version This prints out the name and version of all modules used and then exits. perl -Mbignum=v -e '' =head2 MATH LIBRARY Math with the numbers is done (by default) by a module called Math::BigInt::Calc. This is equivalent to saying: use bignum lib => 'Calc'; You can change this by using: use bignum 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 bignum lib => 'Foo,Math::BigInt::Bar'; Please see respective module documentation for further details. =head2 INTERNAL FORMAT The numbers are stored as objects, and their internals might change at anytime, especially between math operations. The objects also might belong to different classes, like Math::BigInt, or Math::BigFLoat. 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 hashkey, nor is a hash underneath at all. =head2 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. =head2 METHODS Since all numbers are now objects, you can use all functions that are part of the BigInt or BigFloat API. It is wise to use only the bxxx() notation, and not the fxxx() notation, though. This makes it possible that the underlying object might morph into a different class than BigFloat. =head1 MODULES USED C 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 bignum: Math::BigInt::Lite (for speed, and only if it is loadable) Math::BigInt Math::BigFloat =head1 EXAMPLES Some cool command line examples to impress the Python crowd ;) perl -Mbignum -le 'print sqrt(33)' perl -Mbignum -le 'print 2*255' perl -Mbignum -le 'print 4.5+2*255' perl -Mbignum -le 'print 3/7 + 5/7 + 8/3' perl -Mbignum -le 'print 123->is_odd()' perl -Mbignum -le 'print log(2)' perl -Mbignum -le 'print 2 ** 0.5' perl -Mbignum=a,65 -le 'print 2 ** 0.2' =head1 LICENSE This program is free software; you may redistribute it and/or modify it under the same terms as Perl itself. =head1 SEE ALSO Especially L as in C. L, L, L and L as well as L, L and L. =head1 AUTHORS (C) by Tels L in early 2002. =cut