8 @EXPORT = qw( inf NaN );
13 ##############################################################################
15 # These are all alike, and thus faked by AUTOLOAD
17 my @faked = qw/round_mode accuracy precision div_scale/;
18 use vars qw/$VERSION $AUTOLOAD $_lite/; # _lite for testsuite
24 $name =~ s/.*:://; # split package
26 foreach my $n (@faked)
30 *{"bigint::$name"} = sub
36 return Math::BigInt->$name($_[0]);
38 return Math::BigInt->$name();
44 # delayed load of Carp and avoid recursion
46 Carp::croak ("Can't call bigint\-\>$name, not a valid method");
51 $Math::BigInt::upgrade;
56 # this takes a binary/hexadecimal/octal constant string and returns it
57 # as string suitable for new. Basically it converts octal to decimal, and
58 # passes every thing else unmodified back.
61 return Math::BigInt->new($string) if $string =~ /^0[bx]/;
63 # so it must be an octal constant
64 Math::BigInt->from_oct($string);
69 # this takes a floating point constant string and returns it truncated to
70 # integer. For instance, '4.5' => '4', '1.234e2' => '123' etc
73 # some simple cases first
74 return $float if ($float =~ /^[+-]?[0-9]+$/); # '+123','-1','0' etc
76 if ($float =~ /^[+-]?[0-9]+\.?[eE]\+?[0-9]+$/); # 123e2, 123.e+2
77 return '0' if ($float =~ /^[+-]?[0]*\.[0-9]+$/); # .2, 0.2, -.1
78 if ($float =~ /^[+-]?[0-9]+\.[0-9]*$/) # 1., 1.23, -1.2 etc
83 my ($mis,$miv,$mfv,$es,$ev) = Math::BigInt::_split($float);
84 return $float if !defined $mis; # doesn't look like a number to me
86 my $sign = $$mis; $sign = '' if $sign eq '+';
89 # ignore fraction part entirely
90 if ($ec >= length($$miv)) # 123.23E-4
94 return $sign . substr ($$miv,0,length($$miv)-$ec); # 1234.45E-2 = 12
97 if ($ec >= length($$mfv))
100 return $sign.$$miv.$$mfv if $ec == 0; # 123.45E+2 => 12345
101 return $sign.$$miv.$$mfv.'E'.$ec; # 123.45e+3 => 12345e1
103 $mfv = substr($$mfv,0,$ec);
104 $sign.$$miv.$mfv; # 123.45e+1 => 1234
109 $^H{bigint} = undef; # no longer in effect
110 overload::remove_constant('binary','','float','','integer');
115 my $level = shift || 0;
116 my $hinthash = (caller($level))[10];
124 $^H{bigint} = 1; # we are in effect
127 my $lib = ''; my $lib_kind = 'try';
129 my @import = ( ':constant' ); # drive it w/ constant
130 my @a = @_; my $l = scalar @_; my $j = 0;
131 my ($ver,$trace); # version? trace?
132 my ($a,$p); # accuracy, precision
133 for ( my $i = 0; $i < $l ; $i++,$j++ )
135 if ($_[$i] =~ /^(l|lib|try|only)$/)
137 # this causes a different low lib to take care...
138 $lib_kind = $1; $lib_kind = 'lib' if $lib_kind eq 'l';
139 $lib = $_[$i+1] || '';
140 my $s = 2; $s = 1 if @a-$j < 2; # avoid "can not modify non-existant..."
141 splice @a, $j, $s; $j -= $s; $i++;
143 elsif ($_[$i] =~ /^(a|accuracy)$/)
146 my $s = 2; $s = 1 if @a-$j < 2; # avoid "can not modify non-existant..."
147 splice @a, $j, $s; $j -= $s; $i++;
149 elsif ($_[$i] =~ /^(p|precision)$/)
152 my $s = 2; $s = 1 if @a-$j < 2; # avoid "can not modify non-existant..."
153 splice @a, $j, $s; $j -= $s; $i++;
155 elsif ($_[$i] =~ /^(v|version)$/)
158 splice @a, $j, 1; $j --;
160 elsif ($_[$i] =~ /^(t|trace)$/)
163 splice @a, $j, 1; $j --;
165 else { die "unknown option $_[$i]"; }
168 $_lite = 0; # using M::BI::L ?
171 require Math::BigInt::Trace; $class = 'Math::BigInt::Trace';
175 # see if we can find Math::BigInt::Lite
176 if (!defined $a && !defined $p) # rounding won't work to well
178 eval 'require Math::BigInt::Lite;';
181 @import = ( ); # :constant in Lite, not MBI
182 Math::BigInt::Lite->import( ':constant' );
183 $_lite= 1; # signal okay
186 require Math::BigInt if $_lite == 0; # not already loaded?
187 $class = 'Math::BigInt'; # regardless of MBIL or not
189 push @import, $lib_kind => $lib if $lib ne '';
190 # Math::BigInt::Trace or plain Math::BigInt
191 $class->import(@import);
193 bigint->accuracy($a) if defined $a;
194 bigint->precision($p) if defined $p;
197 print "bigint\t\t\t v$VERSION\n";
198 print "Math::BigInt::Lite\t v$Math::BigInt::Lite::VERSION\n" if $_lite;
199 print "Math::BigInt\t\t v$Math::BigInt::VERSION";
200 my $config = Math::BigInt->config();
201 print " lib => $config->{lib} v$config->{lib_version}\n";
204 # we take care of floating point constants, since BigFloat isn't available
205 # and BigInt doesn't like them:
206 overload::constant float => sub { Math::BigInt->new( _float_constant(shift) ); };
207 # Take care of octal/hexadecimal constants
208 overload::constant binary => sub { _binary_constant(shift) };
210 # if another big* was already loaded:
211 my ($package) = caller();
214 if (!defined *{"${package}::inf"})
216 $self->export_to_level(1,$self,@a); # export inf and NaN
220 sub inf () { Math::BigInt->binf(); }
221 sub NaN () { Math::BigInt->bnan(); }
229 bigint - Transparent BigInteger support for Perl
235 $x = 2 + 4.5,"\n"; # BigInt 6
236 print 2 ** 512,"\n"; # really is what you think it is
237 print inf + 42,"\n"; # inf
238 print NaN * 7,"\n"; # NaN
242 print 2 ** 256,"\n"; # a normal Perl scalar now
247 All operators (including basic math operations) are overloaded. Integer
248 constants are created as proper BigInts.
250 Floating point constants are truncated to integer. All parts and results of
251 expressions are also truncated.
253 Unlike L<integer>, this pragma creates integer constants that are only
254 limited in their size by the available memory and CPU time.
256 =head2 use integer vs. use bigint
258 There is one small difference between C<use integer> and C<use bigint>: the
259 former will not affect assignments to variables and the return value of
260 some functions. C<bigint> truncates these results to integer too:
262 # perl -Minteger -wle 'print 3.2'
264 # perl -Minteger -wle 'print 3.2 + 0'
266 # perl -Mbigint -wle 'print 3.2'
268 # perl -Mbigint -wle 'print 3.2 + 0'
271 # perl -Mbigint -wle 'print exp(1) + 0'
273 # perl -Mbigint -wle 'print exp(1)'
275 # perl -Mbigint -wle 'print exp(1)'
277 # perl -Mbigint -wle 'print exp(1) + 0'
280 In practice this makes seldom a difference as B<parts and results> of
281 expressions will be truncated anyway, but this can, for instance, affect the
282 return value of subroutines:
284 sub three_integer { use integer; return 3.2; }
285 sub three_bigint { use bigint; return 3.2; }
287 print three_integer(), " ", three_bigint(),"\n"; # prints "3.2 3"
291 bigint recognizes some options that can be passed while loading it via use.
292 The options can (currently) be either a single letter form, or the long form.
293 The following options exist:
299 This sets the accuracy for all math operations. The argument must be greater
300 than or equal to zero. See Math::BigInt's bround() function for details.
302 perl -Mbigint=a,2 -le 'print 12345+1'
304 Note that setting precision and accurary at the same time is not possible.
308 This sets the precision for all math operations. The argument can be any
309 integer. Negative values mean a fixed number of digits after the dot, and
310 are <B>ignored</B> since all operations happen in integer space.
311 A positive value rounds to this digit left from the dot. 0 or 1 mean round to
312 integer and are ignore like negative values.
314 See Math::BigInt's bfround() function for details.
316 perl -Mbignum=p,5 -le 'print 123456789+123'
318 Note that setting precision and accurary at the same time is not possible.
322 This enables a trace mode and is primarily for debugging bigint or
325 =item l, lib, try or only
327 Load a different math lib, see L<Math Library>.
329 perl -Mbigint=lib,GMP -e 'print 2 ** 512'
330 perl -Mbigint=try,GMP -e 'print 2 ** 512'
331 perl -Mbigint=only,GMP -e 'print 2 ** 512'
333 Currently there is no way to specify more than one library on the command
334 line. This means the following does not work:
336 perl -Mbignum=l,GMP,Pari -e 'print 2 ** 512'
338 This will be hopefully fixed soon ;)
342 This prints out the name and version of all modules used and then exits.
350 Math with the numbers is done (by default) by a module called
351 Math::BigInt::Calc. This is equivalent to saying:
353 use bigint lib => 'Calc';
355 You can change this by using:
357 use bignum lib => 'GMP';
359 The following would first try to find Math::BigInt::Foo, then
360 Math::BigInt::Bar, and when this also fails, revert to Math::BigInt::Calc:
362 use bigint lib => 'Foo,Math::BigInt::Bar';
364 Using C<lib> warns if none of the specified libraries can be found and
365 L<Math::BigInt> did fall back to one of the default libraries.
366 To supress this warning, use C<try> instead:
368 use bignum try => 'GMP';
370 If you want the code to die instead of falling back, use C<only> instead:
372 use bignum only => 'GMP';
374 Please see respective module documentation for further details.
376 =head2 Internal Format
378 The numbers are stored as objects, and their internals might change at anytime,
379 especially between math operations. The objects also might belong to different
380 classes, like Math::BigInt, or Math::BigInt::Lite. Mixing them together, even
381 with normal scalars is not extraordinary, but normal and expected.
383 You should not depend on the internal format, all accesses must go through
384 accessor methods. E.g. looking at $x->{sign} is not a good idea since there
385 is no guaranty that the object in question has such a hash key, nor is a hash
390 The sign is either '+', '-', 'NaN', '+inf' or '-inf'.
391 You can access it with the sign() method.
393 A sign of 'NaN' is used to represent the result when input arguments are not
394 numbers or as a result of 0/0. '+inf' and '-inf' represent plus respectively
395 minus infinity. You will get '+inf' when dividing a positive number by 0, and
396 '-inf' when dividing any negative number by 0.
400 Since all numbers are now objects, you can use all functions that are part of
401 the BigInt API. You can only use the bxxx() notation, and not the fxxx()
408 A shortcut to return Math::BigInt->binf(). Useful because Perl does not always
409 handle bareword C<inf> properly.
413 A shortcut to return Math::BigInt->bnan(). Useful because Perl does not always
414 handle bareword C<NaN> properly.
418 Return the class that numbers are upgraded to, is in fact returning
419 C<$Math::BigInt::upgrade>.
425 print "in effect\n" if bigint::in_effect; # true
428 print "in effect\n" if bigint::in_effect; # false
431 Returns true or false if C<bigint> is in effect in the current scope.
433 This method only works on Perl v5.9.4 or later.
439 Math with the numbers is done (by default) by a module called
443 But a warning is in order. When using the following to make a copy of a number,
444 only a shallow copy will be made.
449 Using the copy or the original with overloaded math is okay, e.g. the
453 print $x + 1, " ", $y,"\n"; # prints 10 9
455 but calling any method that modifies the number directly will result in
456 B<both> the original and the copy being destroyed:
459 print $x->badd(1), " ", $y,"\n"; # prints 10 10
462 print $x->binc(1), " ", $y,"\n"; # prints 10 10
465 print $x->bmul(2), " ", $y,"\n"; # prints 18 18
467 Using methods that do not modify, but testthe contents works:
470 $z = 9 if $x->is_zero(); # works fine
472 See the documentation about the copy constructor and C<=> in overload, as
473 well as the documentation in BigInt for further details.
477 C<bigint> is just a thin wrapper around various modules of the Math::BigInt
478 family. Think of it as the head of the family, who runs the shop, and orders
479 the others to do the work.
481 The following modules are currently used by bigint:
483 Math::BigInt::Lite (for speed, and only if it is loadable)
488 Some cool command line examples to impress the Python crowd ;) You might want
489 to compare them to the results under -Mbignum or -Mbigrat:
491 perl -Mbigint -le 'print sqrt(33)'
492 perl -Mbigint -le 'print 2*255'
493 perl -Mbigint -le 'print 4.5+2*255'
494 perl -Mbigint -le 'print 3/7 + 5/7 + 8/3'
495 perl -Mbigint -le 'print 123->is_odd()'
496 perl -Mbigint -le 'print log(2)'
497 perl -Mbigint -le 'print 2 ** 0.5'
498 perl -Mbigint=a,65 -le 'print 2 ** 0.2'
499 perl -Mbignum=a,65,l,GMP -le 'print 7 ** 7777'
503 This program is free software; you may redistribute it and/or modify it under
504 the same terms as Perl itself.
508 Especially L<bigrat> as in C<perl -Mbigrat -le 'print 1/3+1/4'> and
509 L<bignum> as in C<perl -Mbignum -le 'print sqrt(2)'>.
511 L<Math::BigInt>, L<Math::BigRat> and L<Math::Big> as well
512 as L<Math::BigInt::BitVect>, L<Math::BigInt::Pari> and L<Math::BigInt::GMP>.
516 (C) by Tels L<http://bloodgate.com/> in early 2002 - 2007.