[perl5.git] / lib / bigrat.pm

package bigrat;
require 5.005;

$VERSION = '0.05';
use Exporter;
@ISA		= qw( Exporter );
@EXPORT_OK	= qw( ); 
@EXPORT		= qw( inf NaN ); 

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 $name)
      {
      *{"bigrat::$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 bigrat\-\>$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;

  # see also bignum->import() for additional comments

  # some defaults
  my $lib = 'Calc'; my $upgrade = 'Math::BigFloat';

  my @import = ( ':constant' );				# drive it w/ constant
  my @a = @_; my $l = scalar @_; my $j = 0;
  my ($a,$p);
  my ($ver,$trace);					# version? trace?
  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 -= $s;
      }
    elsif ($_[$i] =~ /^(l|lib)$/)
      {
      # 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 -= $s;
      }
    elsif ($_[$i] =~ /^(v|version)$/)
      {
      $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);

  require Math::BigFloat;
  Math::BigFloat->import( upgrade => 'Math::BigRat', ':constant' );
  require Math::BigRat;
  if ($ver)
    {
    print "bigrat\t\t\t v$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$Math::BigFloat::VERSION\n";
    print "Math::BigRat\t\t v$Math::BigRat::VERSION\n";
    exit;
    }
  $self->export_to_level(1,$self,@a);           # export inf and NaN
  }

sub inf () { Math::BigInt->binf(); }
sub NaN () { Math::BigInt->bnan(); }

1;

__END__

=head1 NAME

bigrat - Transparent BigNumber/BigRationale support for Perl

=head1 SYNOPSIS

  use bigrat;

  $x = 2 + 4.5,"\n";			# BigFloat 6.5
  print 1/3 + 1/4,"\n";			# produces 7/12

=head1 DESCRIPTION

All operators (inlcuding basic math operations) are overloaded. Integer and
floating-point constants are created as proper BigInts or BigFloats,
respectively.

Other than L<bignum>, this module upgrades to Math::BigRat, meaning that
instead of 2.5 you will get 2+1/2 as output.

=head2 MODULES USED

C<bigrat> 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
        Math::BigRat

=head2 MATH LIBRARY

Math with the numbers is done (by default) by a module called
Math::BigInt::Calc. This is equivalent to saying:

	use bigrat lib => 'Calc';

You can change this by using:

	use bigrat 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 bigrat lib => 'Foo,Math::BigInt::Bar';

Please see respective module documentation for further details.

=head2 SIGN

The sign is either '+', '-', 'NaN', '+inf' or '-inf' and stored seperately.

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 not 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 you independed on the fact that the
underlying object might morph into a different class than BigFloat.

=head1 EXAMPLES
 
	perl -Mbigrat -le 'print sqrt(33)'
	perl -Mbigrat -le 'print 2*255'
	perl -Mbigrat -le 'print 4.5+2*255'
	perl -Mbigrat -le 'print 3/7 + 5/7 + 8/3'	
	perl -Mbigrat -le 'print 12->is_odd()';

=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<bignum>.

L<Math::BigFloat>, L<Math::BigInt>, L<Math::BigRat> and L<Math::Big> as well
as L<Math::BigInt::BitVect>, L<Math::BigInt::Pari> and  L<Math::BigInt::GMP>.

=head1 AUTHORS

(C) by Tels L<http://bloodgate.com/> in early 2002.

=cut
Commit	Line	Data
126f3c5f JH	1	package bigrat;
	2	require 5.005;
	3
b4bc5691	4	$VERSION = '0.05';
126f3c5f	5	use Exporter;
b4bc5691 T	6	@ISA = qw( Exporter );
	7	@EXPORT_OK = qw( );
	8	@EXPORT = qw( inf NaN );
126f3c5f JH	9
	10	use strict;
	11
	12	##############################################################################
	13
	14	# These are all alike, and thus faked by AUTOLOAD
	15
	16	my @faked = qw/round_mode accuracy precision div_scale/;
	17	use vars qw/$VERSION $AUTOLOAD $_lite/; # _lite for testsuite
	18
	19	sub AUTOLOAD
	20	{
	21	my $name = $AUTOLOAD;
	22
	23	$name =~ s/.*:://; # split package
	24	no strict 'refs';
	25	foreach my $n (@faked)
	26	{
	27	if ($n eq $name)
	28	{
	29	*{"bigrat::$name"} = sub
	30	{
	31	my $self = shift;
	32	no strict 'refs';
	33	if (defined $_[0])
	34	{
	35	Math::BigInt->$name($_[0]);
	36	Math::BigFloat->$name($_[0]);
	37	}
	38	return Math::BigInt->$name();
	39	};
	40	return &$name;
	41	}
	42	}
	43
	44	# delayed load of Carp and avoid recursion
	45	require Carp;
	46	Carp::croak ("Can't call bigrat\-\>$name, not a valid method");
	47	}
	48
	49	sub upgrade
	50	{
	51	my $self = shift;
	52	no strict 'refs';
	53	# if (defined $_[0])
	54	# {
	55	# $Math::BigInt::upgrade = $_[0];
	56	# $Math::BigFloat::upgrade = $_[0];
	57	# }
	58	return $Math::BigInt::upgrade;
	59	}
	60
	61	sub import
	62	{
	63	my $self = shift;
	64
	65	# see also bignum->import() for additional comments
	66
	67	# some defaults
	68	my $lib = 'Calc'; my $upgrade = 'Math::BigFloat';
	69
	70	my @import = ( ':constant' ); # drive it w/ constant
	71	my @a = @_; my $l = scalar @_; my $j = 0;
	72	my ($a,$p);
73	my ($ver,$trace); # version? trace?
74	for ( my $i = 0; $i < $l ; $i++,$j++ )
75	{
76	if ($_[$i] eq 'upgrade')
77	{
78	# this causes upgrading
79	$upgrade = $_[$i+1]; # or undef to disable
80	my $s = 2; $s = 1 if @a-$j < 2; # avoid "can not modify non-existant..."
81	splice @a, $j, $s; $j -= $s;
82	}
83	elsif ($_[$i] =~ /^(l\|lib)$/)
84	{
85	# this causes a different low lib to take care...
86	$lib = $_[$i+1] \|\| '';
87	my $s = 2; $s = 1 if @a-$j < 2; # avoid "can not modify non-existant..."
88	splice @a, $j, $s; $j -= $s;
89	}
90	elsif ($_[$i] =~ /^(v\|version)$/)
91	{
92	$ver = 1;
93	splice @a, $j, 1; $j --;
94	}
95	elsif ($_[$i] =~ /^(t\|trace)$/)
96	{
97	$trace = 1;
98	splice @a, $j, 1; $j --;
99	}
100	else
101	{
102	die ("unknown option $_[$i]");
103	}
104	}
105	my $class;
106	$_lite = 0; # using M::BI::L ?
107	if ($trace)
108	{
109	require Math::BigInt::Trace; $class = 'Math::BigInt::Trace';
110	$upgrade = 'Math::BigFloat::Trace';
126f3c5f JH	111	}
	112	else
	113	{
	114	# see if we can find Math::BigInt::Lite
	115	if (!defined $a && !defined $p) # rounding won't work to well
	116	{
	117	eval 'require Math::BigInt::Lite;';
	118	if ($@ eq '')
	119	{
	120	@import = ( ); # :constant in Lite, not MBI
	121	Math::BigInt::Lite->import( ':constant' );
	122	$_lite= 1; # signal okay
	123	}
	124	}
	125	require Math::BigInt if $_lite == 0; # not already loaded?
	126	$class = 'Math::BigInt'; # regardless of MBIL or not
	127	}
	128	# Math::BigInt::Trace or plain Math::BigInt
	129	$class->import(@import, upgrade => $upgrade, lib => $lib);
	130
	131	require Math::BigFloat;
	132	Math::BigFloat->import( upgrade => 'Math::BigRat', ':constant' );
	133	require Math::BigRat;
	134	if ($ver)
	135	{
	136	print "bigrat\t\t\t v$VERSION\n";
	137	print "Math::BigInt::Lite\t v$Math::BigInt::Lite::VERSION\n" if $_lite;
	138	print "Math::BigInt\t\t v$Math::BigInt::VERSION";
	139	my $config = Math::BigInt->config();
	140	print " lib => $config->{lib} v$config->{lib_version}\n";
	141	print "Math::BigFloat\t\t v$Math::BigFloat::VERSION\n";
	142	print "Math::BigRat\t\t v$Math::BigRat::VERSION\n";
	143	exit;
	144	}
b4bc5691	145	$self->export_to_level(1,$self,@a); # export inf and NaN
126f3c5f JH	146	}
126f3c5f JH	147
b4bc5691 T	148	sub inf () { Math::BigInt->binf(); }
	149	sub NaN () { Math::BigInt->bnan(); }
	150
126f3c5f JH	151	1;
	152
	153	__END__
	154
	155	=head1 NAME
	156
b4bc5691	157	bigrat - Transparent BigNumber/BigRationale support for Perl
126f3c5f JH	158
	159	=head1 SYNOPSIS
	160
	161	use bigrat;
	162
	163	$x = 2 + 4.5,"\n"; # BigFloat 6.5
	164	print 1/3 + 1/4,"\n"; # produces 7/12
	165
	166	=head1 DESCRIPTION
	167
	168	All operators (inlcuding basic math operations) are overloaded. Integer and
	169	floating-point constants are created as proper BigInts or BigFloats,
	170	respectively.
	171
	172	Other than L<bignum>, this module upgrades to Math::BigRat, meaning that
	173	instead of 2.5 you will get 2+1/2 as output.
	174
	175	=head2 MODULES USED
	176
	177	C<bigrat> is just a thin wrapper around various modules of the Math::BigInt
	178	family. Think of it as the head of the family, who runs the shop, and orders
	179	the others to do the work.
	180
	181	The following modules are currently used by bignum:
	182
	183	Math::BigInt::Lite (for speed, and only if it is loadable)
	184	Math::BigInt
	185	Math::BigFloat
	186	Math::BigRat
	187
	188	=head2 MATH LIBRARY
	189
	190	Math with the numbers is done (by default) by a module called
	191	Math::BigInt::Calc. This is equivalent to saying:
	192
	193	use bigrat lib => 'Calc';
	194
	195	You can change this by using:
	196
	197	use bigrat lib => 'BitVect';
	198
	199	The following would first try to find Math::BigInt::Foo, then
	200	Math::BigInt::Bar, and when this also fails, revert to Math::BigInt::Calc:
	201
	202	use bigrat lib => 'Foo,Math::BigInt::Bar';
	203
	204	Please see respective module documentation for further details.
	205
	206	=head2 SIGN
	207
	208	The sign is either '+', '-', 'NaN', '+inf' or '-inf' and stored seperately.
	209
	210	A sign of 'NaN' is used to represent the result when input arguments are not
	211	numbers or as a result of 0/0. '+inf' and '-inf' represent plus respectively
	212	minus infinity. You will get '+inf' when dividing a positive number by 0, and
	213	'-inf' when dividing any negative number by 0.
	214
	215	=head2 METHODS
	216
	217	Since all numbers are not objects, you can use all functions that are part of
	218	the BigInt or BigFloat API. It is wise to use only the bxxx() notation, and not
	219	the fxxx() notation, though. This makes you independed on the fact that the
	220	underlying object might morph into a different class than BigFloat.
	221
222	=head1 EXAMPLES
223
224	perl -Mbigrat -le 'print sqrt(33)'
225	perl -Mbigrat -le 'print 2*255'
226	perl -Mbigrat -le 'print 4.5+2*255'
227	perl -Mbigrat -le 'print 3/7 + 5/7 + 8/3'
228	perl -Mbigrat -le 'print 12->is_odd()';
229
230	=head1 LICENSE
231
232	This program is free software; you may redistribute it and/or modify it under
233	the same terms as Perl itself.
234
235	=head1 SEE ALSO
236
237	Especially L<bignum>.
238
239	L<Math::BigFloat>, L<Math::BigInt>, L<Math::BigRat> and L<Math::Big> as well
240	as L<Math::BigInt::BitVect>, L<Math::BigInt::Pari> and L<Math::BigInt::GMP>.
241
242	=head1 AUTHORS
243
244	(C) by Tels L<http://bloodgate.com/> in early 2002.
245
246	=cut