package bigint;
require 5.005;
$VERSION = '0.05';
use Exporter;
@ISA = qw( Exporter );
@EXPORT_OK = qw( );
@EXPORT = qw( inf NaN );
use strict;
use overload;
##############################################################################
# These are all alike, and thus faked by AUTOLOAD
my @faked = qw/round_mode accuracy precision div_scale/;
use vars qw/$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 $name)
{
*{"bigint::$name"} = sub
{
my $self = shift;
no strict 'refs';
if (defined $_[0])
{
return Math::BigInt->$name($_[0]);
}
return Math::BigInt->$name();
};
return &$name;
}
}
# delayed load of Carp and avoid recursion
require Carp;
Carp::croak ("Can't call bigint\-\>$name, not a valid method");
}
sub upgrade
{
my $self = shift;
no strict 'refs';
# if (defined $_[0])
# {
# $Math::BigInt::upgrade = $_[0];
# }
return $Math::BigInt::upgrade;
}
sub _constant
{
# this takes a floating point constant string and returns it truncated to
# integer. For instance, '4.5' => '4', '1.234e2' => '123' etc
my $float = shift;
# some simple cases first
return $float if ($float =~ /^[+-]?[0-9]+$/); # '+123','-1','0' etc
return $float
if ($float =~ /^[+-]?[0-9]+\.?[eE]\+?[0-9]+$/); # 123e2, 123.e+2
return '0' if ($float =~ /^[+-]?[0]*\.[0-9]+$/); # .2, 0.2, -.1
if ($float =~ /^[+-]?[0-9]+\.[0-9]*$/) # 1., 1.23, -1.2 etc
{
$float =~ s/\..*//;
return $float;
}
my ($mis,$miv,$mfv,$es,$ev) = Math::BigInt::_split($float);
return $float if !defined $mis; # doesn't look like a number to me
my $ec = int($$ev);
my $sign = $$mis; $sign = '' if $sign eq '+';
if ($$es eq '-')
{
# ignore fraction part entirely
if ($ec >= length($$miv)) # 123.23E-4
{
return '0';
}
return $sign . substr ($$miv,0,length($$miv)-$ec); # 1234.45E-2 = 12
}
# xE+y
if ($ec >= length($$mfv))
{
$ec -= length($$mfv);
return $sign.$$miv.$$mfv if $ec == 0; # 123.45E+2 => 12345
return $sign.$$miv.$$mfv.'E'.$ec; # 123.45e+3 => 12345e1
}
$mfv = substr($$mfv,0,$ec);
return $sign.$$miv.$mfv; # 123.45e+1 => 1234
}
sub import
{
my $self = shift;
# some defaults
my $lib = 'Calc';
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] =~ /^(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';
}
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, lib => $lib);
bigint->accuracy($a) if defined $a;
bigint->precision($p) if defined $p;
if ($ver)
{
print "bigint\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";
exit;
}
# we take care of floating point constants, since BigFloat isn't available
# and BigInt doesn't like them:
overload::constant float => sub { Math::BigInt->new( _constant(shift) ); };
$self->export_to_level(1,$self,@a); # export inf and NaN
}
sub inf () { Math::BigInt->binf(); }
sub NaN () { Math::BigInt->bnan(); }
1;
__END__
=head1 NAME
bigint - Transparent BigInteger support for Perl
=head1 SYNOPSIS
use bignt;
$x = 2 + 4.5,"\n"; # BigInt 6
print 2 ** 512,"\n"; # really is what you think it is
print inf + 42,"\n"; # inf
print NaN * 7,"\n"; # NaN
=head1 DESCRIPTION
All operators (including basic math operations) are overloaded. Integer
constants are created as proper BigInts.
Floating point constants are truncated to integer. All results are also
truncated.
=head2 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:
=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 -Mbigint=a,2 -le 'print 12345+1'
=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, and
are **ignored** 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'
=item t or trace
This enables a trace mode and is primarily for debugging bigint or
Math::BigInt.
=item l or lib
Load a different math lib, see L