package bignum;
use 5.006002;
-$VERSION = '0.19';
+$VERSION = '0.22';
use Exporter;
-@EXPORT_OK = qw( );
+@ISA = qw( bigint );
+@EXPORT_OK = qw( PI e bexp bpi );
@EXPORT = qw( inf NaN );
-@ISA = qw( Exporter );
use strict;
use overload;
+require bigint; # no "use" to avoid import being called
##############################################################################
+BEGIN
+ {
+ *inf = \&bigint::inf;
+ *NaN = \&bigint::NaN;
+ }
+
# These are all alike, and thus faked by AUTOLOAD
my @faked = qw/round_mode accuracy precision div_scale/;
Carp::croak ("Can't call bignum\-\>$name, not a valid method");
}
-sub upgrade
+sub unimport
{
- my $self = shift;
- no strict 'refs';
-# if (defined $_[0])
-# {
-# $Math::BigInt::upgrade = $_[0];
-# $Math::BigFloat::upgrade = $_[0];
-# }
- $Math::BigInt::upgrade;
+ $^H{bignum} = undef; # no longer in effect
+ overload::remove_constant('binary','','float','','integer');
}
-sub _binary_constant
+sub in_effect
{
- # this takes a binary/hexadecimal/octal constant string and returns it
- # as string suitable for new. Basically it converts octal to decimal, and
- # passes every thing else unmodified back.
- my $string = shift;
+ my $level = shift || 0;
+ my $hinthash = (caller($level))[10];
+ $hinthash->{bignum};
+ }
- return Math::BigInt->new($string) if $string =~ /^0[bx]/;
+#############################################################################
+# the following two routines are for Perl 5.9.4 or later and are lexical
- # so it must be an octal constant
- Math::BigInt->from_oct($string);
+sub _hex
+ {
+ return CORE::hex($_[0]) unless in_effect(1);
+ my $i = $_[0];
+ $i = '0x'.$i unless $i =~ /^0x/;
+ Math::BigInt->new($i);
+ }
+
+sub _oct
+ {
+ return CORE::oct($_[0]) unless in_effect(1);
+ my $i = $_[0];
+ return Math::BigInt->from_oct($i) if $i =~ /^0[0-7]/;
+ Math::BigInt->new($i);
}
sub import
{
my $self = shift;
+ $^H{bignum} = 1; # we are in effect
+
+ my ($hex,$oct);
+
+ # for newer Perls override hex() and oct() with a lexical version:
+ if ($] > 5.009003)
+ {
+ $hex = \&_hex;
+ $oct = \&_oct;
+ }
+
# some defaults
- my $lib = '';
+ my $lib = ''; my $lib_kind = 'try';
my $upgrade = 'Math::BigFloat';
my $downgrade = 'Math::BigInt';
my $s = 2; $s = 1 if @a-$j < 2; # avoid "can not modify non-existant..."
splice @a, $j, $s; $j -= $s; $i++;
}
- elsif ($_[$i] =~ /^(l|lib)$/)
+ elsif ($_[$i] =~ /^(l|lib|try|only)$/)
{
# this causes a different low lib to take care...
+ $lib_kind = $1; $lib_kind = 'lib' if $lib_kind eq 'l';
$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++;
$trace = 1;
splice @a, $j, 1; $j --;
}
- else { die "unknown option $_[$i]"; }
+ elsif ($_[$i] eq 'hex')
+ {
+ splice @a, $j, 1; $j --;
+ $hex = \&bigint::_hex_global;
+ }
+ elsif ($_[$i] eq 'oct')
+ {
+ splice @a, $j, 1; $j --;
+ $oct = \&bigint::_oct_global;
+ }
+ elsif ($_[$i] !~ /^(PI|e|bexp|bpi)\z/)
+ {
+ die ("unknown option $_[$i]");
+ }
}
my $class;
$_lite = 0; # using M::BI::L ?
require Math::BigInt if $_lite == 0; # not already loaded?
$class = 'Math::BigInt'; # regardless of MBIL or not
}
- push @import, 'try' => $lib if $lib ne '';
+ push @import, $lib_kind => $lib if $lib ne '';
# Math::BigInt::Trace or plain Math::BigInt
$class->import(@import, upgrade => $upgrade);
}
# Take care of octal/hexadecimal constants
- overload::constant 'binary' => sub { _binary_constant(shift) };
+ overload::constant binary => sub { bigint::_binary_constant(shift) };
- $self->export_to_level(1,$self,@a); # export inf and NaN
+ # if another big* was already loaded:
+ my ($package) = caller();
+
+ no strict 'refs';
+ if (!defined *{"${package}::inf"})
+ {
+ $self->export_to_level(1,$self,@a); # export inf and NaN
+ }
+ {
+ no warnings 'redefine';
+ *CORE::GLOBAL::oct = $oct if $oct;
+ *CORE::GLOBAL::hex = $hex if $hex;
+ }
}
-sub inf () { Math::BigInt->binf(); }
-sub NaN () { Math::BigInt->bnan(); }
+sub PI () { Math::BigFloat->new('3.141592653589793238462643383279502884197'); }
+sub e () { Math::BigFloat->new('2.718281828459045235360287471352662497757'); }
+sub bpi ($) { Math::BigFloat::bpi(@_); }
+sub bexp ($$) { my $x = Math::BigFloat->new($_[0]); $x->bexp($_[1]); }
1;
print inf * inf,"\n"; # prints inf
print NaN * 3,"\n"; # prints NaN
+ {
+ no bignum;
+ print 2 ** 256,"\n"; # a normal Perl scalar now
+ }
+
+ # for older Perls, note that this will be global:
+ use bignum qw/hex oct/;
+ print hex("0x1234567890123490"),"\n";
+ print oct("01234567890123490"),"\n";
+
=head1 DESCRIPTION
All operators (including basic math operations) are overloaded. Integer and
BigInt/BigFloat on them. This even works to some extent on expressions:
perl -Mbignum -le '$x = 1234; print $x->bdec()'
- perl -Mbignum -le 'print 1234->binc();'
- perl -Mbignum -le 'print 1234->binc->badd(6);'
- perl -Mbignum -le 'print +(1234)->binc()'
+ perl -Mbignum -le 'print 1234->copy()->binc();'
+ perl -Mbignum -le 'print 1234->copy()->binc->badd(6);'
+ perl -Mbignum -le 'print +(1234)->copy()->binc()'
(Note that print doesn't do what you expect if the expression starts with
'(' hence the C<+>)
You can even chain the operations together as usual:
- perl -Mbignum -le 'print 1234->binc->badd(6);'
+ perl -Mbignum -le 'print 1234->copy()->binc->badd(6);'
1241
Under bignum (or bigint or bigrat), Perl will "upgrade" the numbers
12381/10
The entire upgrading/downgrading is still experimental and might not work
-as you expect or may even have bugs.
-
-You might get errors like this:
+as you expect or may even have bugs. You might get errors like this:
Can't use an undefined value as an ARRAY reference at
/usr/local/lib/perl5/5.8.0/Math/BigInt/Calc.pm line 864
This will be hopefully fixed soon ;)
+=item hex
+
+Override the built-in hex() method with a version that can handle big
+integers. Note that under Perl older than v5.9.4, this will be global
+and cannot be disabled with "no bigint;".
+
+=item oct
+
+Override the built-in oct() method with a version that can handle big
+integers. Note that under Perl older than v5.9.4, this will be global
+and cannot be disabled with "no bigint;".
+
=item v or version
This prints out the name and version of all modules used and then exits.
the fxxx() notation, though. This makes it possible that the underlying object
might morph into a different class than BigFloat.
-=head2 Caveat
+=head2 Caveats
But a warning is in order. When using the following to make a copy of a number,
only a shallow copy will be made.
$x = 9; $y = $x;
print $x->bmul(2), " ", $y,"\n"; # prints 18 18
-Using methods that do not modify, but testthe contents works:
+Using methods that do not modify, but test the contents works:
$x = 9; $y = $x;
$z = 9 if $x->is_zero(); # works fine
A shortcut to return Math::BigInt->bnan(). Useful because Perl does not always
handle bareword C<NaN> properly.
+=item e
+
+ # perl -Mbignum=e -wle 'print e'
+
+Returns Euler's number C<e>, aka exp(1).
+
+=item PI()
+
+ # perl -Mbignum=PI -wle 'print PI'
+
+Returns PI.
+
+=item bexp()
+
+ bexp($power,$accuracy);
+
+Returns Euler's number C<e> raised to the appropriate power, to
+the wanted accuracy.
+
+Example:
+
+ # perl -Mbignum=bexp -wle 'print bexp(1,80)'
+
+=item bpi()
+
+ bpi($accuracy);
+
+Returns PI to the wanted accuracy.
+
+Example:
+
+ # perl -Mbignum=bpi -wle 'print bpi(80)'
+
=item upgrade()
Return the class that numbers are upgraded to, is in fact returning
C<$Math::BigInt::upgrade>.
+=item in_effect()
+
+ use bignum;
+
+ print "in effect\n" if bignum::in_effect; # true
+ {
+ no bignum;
+ print "in effect\n" if bignum::in_effect; # false
+ }
+
+Returns true or false if C<bignum> is in effect in the current scope.
+
+This method only works on Perl v5.9.4 or later.
+
=back
-=head2 MATH LIBRARY
+=head2 Math Library
Math with the numbers is done (by default) by a module called
Math::BigInt::Calc. This is equivalent to saying:
You can change this by using:
- use bignum lib => 'BitVect';
+ use bignum lib => 'GMP';
The following would first try to find Math::BigInt::Foo, then
Math::BigInt::Bar, and when this also fails, revert to Math::BigInt::Calc:
Please see respective module documentation for further details.
+Using C<lib> warns if none of the specified libraries can be found and
+L<Math::BigInt> did fall back to one of the default libraries.
+To supress this warning, use C<try> instead:
+
+ use bignum try => 'GMP';
+
+If you want the code to die instead of falling back, use C<only> instead:
+
+ use bignum only => 'GMP';
+
=head2 INTERNAL FORMAT
The numbers are stored as objects, and their internals might change at anytime,
minus infinity. You will get '+inf' when dividing a positive number by 0, and
'-inf' when dividing any negative number by 0.
+=head1 CAVAETS
+
+=over 2
+
+=item in_effect()
+
+This method only works on Perl v5.9.4 or later.
+
+=item hex()/oct()
+
+C<bigint> overrides these routines with versions that can also handle
+big integer values. Under Perl prior to version v5.9.4, however, this
+will not happen unless you specifically ask for it with the two
+import tags "hex" and "oct" - and then it will be global and cannot be
+disabled inside a scope with "no bigint":
+
+ use bigint qw/hex oct/;
+
+ print hex("0x1234567890123456");
+ {
+ no bigint;
+ print hex("0x1234567890123456");
+ }
+
+The second call to hex() will warn about a non-portable constant.
+
+Compare this to:
+
+ use bigint;
+
+ # will warn only under older than v5.9.4
+ print hex("0x1234567890123456");
+
+=back
+
=head1 MODULES USED
C<bignum> is just a thin wrapper around various modules of the Math::BigInt
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 exp(1)'
perl -Mbignum -le 'print 2 ** 0.5'
perl -Mbignum=a,65 -le 'print 2 ** 0.2'
perl -Mbignum=a,65,l,GMP -le 'print 7 ** 7777'
https://perl5.git.perl.org / perl5.git / blobdiff