7 @EXPORT = qw( inf NaN );
12 ##############################################################################
14 # These are all alike, and thus faked by AUTOLOAD
16 my @faked = qw/round_mode accuracy precision div_scale/;
17 use vars qw/$VERSION $AUTOLOAD $_lite/; # _lite for testsuite
23 $name =~ s/.*:://; # split package
25 foreach my $n (@faked)
29 *{"bignum::$name"} = sub
35 Math::BigInt->$name($_[0]);
36 Math::BigFloat->$name($_[0]);
38 return Math::BigInt->$name();
44 # delayed load of Carp and avoid recursion
46 Carp::croak ("Can't call bignum\-\>$name, not a valid method");
55 # $Math::BigInt::upgrade = $_[0];
56 # $Math::BigFloat::upgrade = $_[0];
58 return $Math::BigInt::upgrade;
67 my $upgrade = 'Math::BigFloat';
68 my $downgrade = 'Math::BigInt';
70 my @import = ( ':constant' ); # drive it w/ constant
71 my @a = @_; my $l = scalar @_; my $j = 0;
72 my ($ver,$trace); # version? trace?
73 my ($a,$p); # accuracy, precision
74 for ( my $i = 0; $i < $l ; $i++,$j++ )
76 if ($_[$i] eq 'upgrade')
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; $i++;
83 elsif ($_[$i] eq 'downgrade')
85 # this causes downgrading
86 $downgrade = $_[$i+1]; # or undef to disable
87 my $s = 2; $s = 1 if @a-$j < 2; # avoid "can not modify non-existant..."
88 splice @a, $j, $s; $j -= $s; $i++;
90 elsif ($_[$i] =~ /^(l|lib)$/)
92 # this causes a different low lib to take care...
93 $lib = $_[$i+1] || '';
94 my $s = 2; $s = 1 if @a-$j < 2; # avoid "can not modify non-existant..."
95 splice @a, $j, $s; $j -= $s; $i++;
97 elsif ($_[$i] =~ /^(a|accuracy)$/)
100 my $s = 2; $s = 1 if @a-$j < 2; # avoid "can not modify non-existant..."
101 splice @a, $j, $s; $j -= $s; $i++;
103 elsif ($_[$i] =~ /^(p|precision)$/)
106 my $s = 2; $s = 1 if @a-$j < 2; # avoid "can not modify non-existant..."
107 splice @a, $j, $s; $j -= $s; $i++;
109 elsif ($_[$i] =~ /^(v|version)$/)
112 splice @a, $j, 1; $j --;
114 elsif ($_[$i] =~ /^(t|trace)$/)
117 splice @a, $j, 1; $j --;
119 else { die "unknown option $_[$i]"; }
122 $_lite = 0; # using M::BI::L ?
125 require Math::BigInt::Trace; $class = 'Math::BigInt::Trace';
126 $upgrade = 'Math::BigFloat::Trace';
130 # see if we can find Math::BigInt::Lite
131 if (!defined $a && !defined $p) # rounding won't work to well
133 eval 'require Math::BigInt::Lite;';
136 @import = ( ); # :constant in Lite, not MBI
137 Math::BigInt::Lite->import( ':constant' );
138 $_lite= 1; # signal okay
141 require Math::BigInt if $_lite == 0; # not already loaded?
142 $class = 'Math::BigInt'; # regardless of MBIL or not
144 # Math::BigInt::Trace or plain Math::BigInt
145 $class->import(@import, upgrade => $upgrade, lib => $lib);
149 require Math::BigFloat::Trace; $class = 'Math::BigFloat::Trace';
150 $downgrade = 'Math::BigInt::Trace';
154 require Math::BigFloat; $class = 'Math::BigFloat';
156 $class->import(':constant','downgrade',$downgrade);
158 bignum->accuracy($a) if defined $a;
159 bignum->precision($p) if defined $p;
162 print "bignum\t\t\t v$VERSION\n";
163 print "Math::BigInt::Lite\t v$Math::BigInt::Lite::VERSION\n" if $_lite;
164 print "Math::BigInt\t\t v$Math::BigInt::VERSION";
165 my $config = Math::BigInt->config();
166 print " lib => $config->{lib} v$config->{lib_version}\n";
167 print "Math::BigFloat\t\t v$Math::BigFloat::VERSION\n";
170 $self->export_to_level(1,$self,@a); # export inf and NaN
173 sub inf () { Math::BigInt->binf(); }
174 sub NaN () { Math::BigInt->bnan(); }
182 bignum - Transparent BigNumber support for Perl
188 $x = 2 + 4.5,"\n"; # BigFloat 6.5
189 print 2 ** 512 * 0.1,"\n"; # really is what you think it is
190 print inf * inf,"\n"; # prints inf
191 print NaN * 3,"\n"; # prints NaN
195 All operators (including basic math operations) are overloaded. Integer and
196 floating-point constants are created as proper BigInts or BigFloats,
201 bignum recognizes some options that can be passed while loading it via use.
202 The options can (currently) be either a single letter form, or the long form.
203 The following options exist:
209 This sets the accuracy for all math operations. The argument must be greater
210 than or equal to zero. See Math::BigInt's bround() function for details.
212 perl -Mbignum=a,50 -le 'print sqrt(20)'
216 This sets the precision for all math operations. The argument can be any
217 integer. Negative values mean a fixed number of digits after the dot, while
218 a positive value rounds to this digit left from the dot. 0 or 1 mean round to
219 integer. See Math::BigInt's bfround() function for details.
221 perl -Mbignum=p,-50 -le 'print sqrt(20)'
225 This enables a trace mode and is primarily for debugging bignum or
226 Math::BigInt/Math::BigFloat.
230 Load a different math lib, see L<MATH LIBRARY>.
232 perl -Mbignum=l,GMP -e 'print 2 ** 512'
234 Currently there is no way to specify more than one library on the command
235 line. This will be hopefully fixed soon ;)
239 This prints out the name and version of all modules used and then exits.
241 perl -Mbignum=v -e ''
245 Beside import() and AUTOLOAD() there are only a few other methods.
251 A shortcut to return Math::BigInt->binf(). Usefull because Perl does not always
252 handle bareword C<inf> properly.
256 A shortcut to return Math::BigInt->bnan(). Usefull because Perl does not always
257 handle bareword C<NaN> properly.
261 Return the class that numbers are upgraded to, is in fact returning
262 C<$Math::BigInt::upgrade>.
268 Math with the numbers is done (by default) by a module called
269 Math::BigInt::Calc. This is equivalent to saying:
271 use bignum lib => 'Calc';
273 You can change this by using:
275 use bignum lib => 'BitVect';
277 The following would first try to find Math::BigInt::Foo, then
278 Math::BigInt::Bar, and when this also fails, revert to Math::BigInt::Calc:
280 use bignum lib => 'Foo,Math::BigInt::Bar';
282 Please see respective module documentation for further details.
284 =head2 INTERNAL FORMAT
286 The numbers are stored as objects, and their internals might change at anytime,
287 especially between math operations. The objects also might belong to different
288 classes, like Math::BigInt, or Math::BigFLoat. Mixing them together, even
289 with normal scalars is not extraordinary, but normal and expected.
291 You should not depend on the internal format, all accesses must go through
292 accessor methods. E.g. looking at $x->{sign} is not a bright idea since there
293 is no guaranty that the object in question has such a hashkey, nor is a hash
298 The sign is either '+', '-', 'NaN', '+inf' or '-inf' and stored seperately.
299 You can access it with the sign() method.
301 A sign of 'NaN' is used to represent the result when input arguments are not
302 numbers or as a result of 0/0. '+inf' and '-inf' represent plus respectively
303 minus infinity. You will get '+inf' when dividing a positive number by 0, and
304 '-inf' when dividing any negative number by 0.
308 Since all numbers are now objects, you can use all functions that are part of
309 the BigInt or BigFloat API. It is wise to use only the bxxx() notation, and not
310 the fxxx() notation, though. This makes it possible that the underlying object
311 might morph into a different class than BigFloat.
315 C<bignum> is just a thin wrapper around various modules of the Math::BigInt
316 family. Think of it as the head of the family, who runs the shop, and orders
317 the others to do the work.
319 The following modules are currently used by bignum:
321 Math::BigInt::Lite (for speed, and only if it is loadable)
327 Some cool command line examples to impress the Python crowd ;)
329 perl -Mbignum -le 'print sqrt(33)'
330 perl -Mbignum -le 'print 2*255'
331 perl -Mbignum -le 'print 4.5+2*255'
332 perl -Mbignum -le 'print 3/7 + 5/7 + 8/3'
333 perl -Mbignum -le 'print 123->is_odd()'
334 perl -Mbignum -le 'print log(2)'
335 perl -Mbignum -le 'print 2 ** 0.5'
336 perl -Mbignum=a,65 -le 'print 2 ** 0.2'
340 This program is free software; you may redistribute it and/or modify it under
341 the same terms as Perl itself.
345 Especially L<bigrat> as in C<perl -Mbigrat -le 'print 1/3+1/4'>.
347 L<Math::BigFloat>, L<Math::BigInt>, L<Math::BigRat> and L<Math::Big> as well
348 as L<Math::BigInt::BitVect>, L<Math::BigInt::Pari> and L<Math::BigInt::GMP>.
352 (C) by Tels L<http://bloodgate.com/> in early 2002.