1 | package bigint;
|
---|
2 | require 5.005;
|
---|
3 |
|
---|
4 | $VERSION = '0.07';
|
---|
5 | use Exporter;
|
---|
6 | @ISA = qw( Exporter );
|
---|
7 | @EXPORT_OK = qw( );
|
---|
8 | @EXPORT = qw( inf NaN );
|
---|
9 |
|
---|
10 | use strict;
|
---|
11 | use overload;
|
---|
12 |
|
---|
13 | ##############################################################################
|
---|
14 |
|
---|
15 | # These are all alike, and thus faked by AUTOLOAD
|
---|
16 |
|
---|
17 | my @faked = qw/round_mode accuracy precision div_scale/;
|
---|
18 | use vars qw/$VERSION $AUTOLOAD $_lite/; # _lite for testsuite
|
---|
19 |
|
---|
20 | sub AUTOLOAD
|
---|
21 | {
|
---|
22 | my $name = $AUTOLOAD;
|
---|
23 |
|
---|
24 | $name =~ s/.*:://; # split package
|
---|
25 | no strict 'refs';
|
---|
26 | foreach my $n (@faked)
|
---|
27 | {
|
---|
28 | if ($n eq $name)
|
---|
29 | {
|
---|
30 | *{"bigint::$name"} = sub
|
---|
31 | {
|
---|
32 | my $self = shift;
|
---|
33 | no strict 'refs';
|
---|
34 | if (defined $_[0])
|
---|
35 | {
|
---|
36 | return Math::BigInt->$name($_[0]);
|
---|
37 | }
|
---|
38 | return Math::BigInt->$name();
|
---|
39 | };
|
---|
40 | return &$name;
|
---|
41 | }
|
---|
42 | }
|
---|
43 |
|
---|
44 | # delayed load of Carp and avoid recursion
|
---|
45 | require Carp;
|
---|
46 | Carp::croak ("Can't call bigint\-\>$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 | # }
|
---|
57 | return $Math::BigInt::upgrade;
|
---|
58 | }
|
---|
59 |
|
---|
60 | sub _constant
|
---|
61 | {
|
---|
62 | # this takes a floating point constant string and returns it truncated to
|
---|
63 | # integer. For instance, '4.5' => '4', '1.234e2' => '123' etc
|
---|
64 | my $float = shift;
|
---|
65 |
|
---|
66 | # some simple cases first
|
---|
67 | return $float if ($float =~ /^[+-]?[0-9]+$/); # '+123','-1','0' etc
|
---|
68 | return $float
|
---|
69 | if ($float =~ /^[+-]?[0-9]+\.?[eE]\+?[0-9]+$/); # 123e2, 123.e+2
|
---|
70 | return '0' if ($float =~ /^[+-]?[0]*\.[0-9]+$/); # .2, 0.2, -.1
|
---|
71 | if ($float =~ /^[+-]?[0-9]+\.[0-9]*$/) # 1., 1.23, -1.2 etc
|
---|
72 | {
|
---|
73 | $float =~ s/\..*//;
|
---|
74 | return $float;
|
---|
75 | }
|
---|
76 | my ($mis,$miv,$mfv,$es,$ev) = Math::BigInt::_split($float);
|
---|
77 | return $float if !defined $mis; # doesn't look like a number to me
|
---|
78 | my $ec = int($$ev);
|
---|
79 | my $sign = $$mis; $sign = '' if $sign eq '+';
|
---|
80 | if ($$es eq '-')
|
---|
81 | {
|
---|
82 | # ignore fraction part entirely
|
---|
83 | if ($ec >= length($$miv)) # 123.23E-4
|
---|
84 | {
|
---|
85 | return '0';
|
---|
86 | }
|
---|
87 | return $sign . substr ($$miv,0,length($$miv)-$ec); # 1234.45E-2 = 12
|
---|
88 | }
|
---|
89 | # xE+y
|
---|
90 | if ($ec >= length($$mfv))
|
---|
91 | {
|
---|
92 | $ec -= length($$mfv);
|
---|
93 | return $sign.$$miv.$$mfv if $ec == 0; # 123.45E+2 => 12345
|
---|
94 | return $sign.$$miv.$$mfv.'E'.$ec; # 123.45e+3 => 12345e1
|
---|
95 | }
|
---|
96 | $mfv = substr($$mfv,0,$ec);
|
---|
97 | return $sign.$$miv.$mfv; # 123.45e+1 => 1234
|
---|
98 | }
|
---|
99 |
|
---|
100 | sub import
|
---|
101 | {
|
---|
102 | my $self = shift;
|
---|
103 |
|
---|
104 | # some defaults
|
---|
105 | my $lib = '';
|
---|
106 |
|
---|
107 | my @import = ( ':constant' ); # drive it w/ constant
|
---|
108 | my @a = @_; my $l = scalar @_; my $j = 0;
|
---|
109 | my ($ver,$trace); # version? trace?
|
---|
110 | my ($a,$p); # accuracy, precision
|
---|
111 | for ( my $i = 0; $i < $l ; $i++,$j++ )
|
---|
112 | {
|
---|
113 | if ($_[$i] =~ /^(l|lib)$/)
|
---|
114 | {
|
---|
115 | # this causes a different low lib to take care...
|
---|
116 | $lib = $_[$i+1] || '';
|
---|
117 | my $s = 2; $s = 1 if @a-$j < 2; # avoid "can not modify non-existant..."
|
---|
118 | splice @a, $j, $s; $j -= $s; $i++;
|
---|
119 | }
|
---|
120 | elsif ($_[$i] =~ /^(a|accuracy)$/)
|
---|
121 | {
|
---|
122 | $a = $_[$i+1];
|
---|
123 | my $s = 2; $s = 1 if @a-$j < 2; # avoid "can not modify non-existant..."
|
---|
124 | splice @a, $j, $s; $j -= $s; $i++;
|
---|
125 | }
|
---|
126 | elsif ($_[$i] =~ /^(p|precision)$/)
|
---|
127 | {
|
---|
128 | $p = $_[$i+1];
|
---|
129 | my $s = 2; $s = 1 if @a-$j < 2; # avoid "can not modify non-existant..."
|
---|
130 | splice @a, $j, $s; $j -= $s; $i++;
|
---|
131 | }
|
---|
132 | elsif ($_[$i] =~ /^(v|version)$/)
|
---|
133 | {
|
---|
134 | $ver = 1;
|
---|
135 | splice @a, $j, 1; $j --;
|
---|
136 | }
|
---|
137 | elsif ($_[$i] =~ /^(t|trace)$/)
|
---|
138 | {
|
---|
139 | $trace = 1;
|
---|
140 | splice @a, $j, 1; $j --;
|
---|
141 | }
|
---|
142 | else { die "unknown option $_[$i]"; }
|
---|
143 | }
|
---|
144 | my $class;
|
---|
145 | $_lite = 0; # using M::BI::L ?
|
---|
146 | if ($trace)
|
---|
147 | {
|
---|
148 | require Math::BigInt::Trace; $class = 'Math::BigInt::Trace';
|
---|
149 | }
|
---|
150 | else
|
---|
151 | {
|
---|
152 | # see if we can find Math::BigInt::Lite
|
---|
153 | if (!defined $a && !defined $p) # rounding won't work to well
|
---|
154 | {
|
---|
155 | eval 'require Math::BigInt::Lite;';
|
---|
156 | if ($@ eq '')
|
---|
157 | {
|
---|
158 | @import = ( ); # :constant in Lite, not MBI
|
---|
159 | Math::BigInt::Lite->import( ':constant' );
|
---|
160 | $_lite= 1; # signal okay
|
---|
161 | }
|
---|
162 | }
|
---|
163 | require Math::BigInt if $_lite == 0; # not already loaded?
|
---|
164 | $class = 'Math::BigInt'; # regardless of MBIL or not
|
---|
165 | }
|
---|
166 | push @import, 'lib' => $lib if $lib ne '';
|
---|
167 | # Math::BigInt::Trace or plain Math::BigInt
|
---|
168 | $class->import(@import);
|
---|
169 |
|
---|
170 | bigint->accuracy($a) if defined $a;
|
---|
171 | bigint->precision($p) if defined $p;
|
---|
172 | if ($ver)
|
---|
173 | {
|
---|
174 | print "bigint\t\t\t v$VERSION\n";
|
---|
175 | print "Math::BigInt::Lite\t v$Math::BigInt::Lite::VERSION\n" if $_lite;
|
---|
176 | print "Math::BigInt\t\t v$Math::BigInt::VERSION";
|
---|
177 | my $config = Math::BigInt->config();
|
---|
178 | print " lib => $config->{lib} v$config->{lib_version}\n";
|
---|
179 | exit;
|
---|
180 | }
|
---|
181 | # we take care of floating point constants, since BigFloat isn't available
|
---|
182 | # and BigInt doesn't like them:
|
---|
183 | overload::constant float => sub { Math::BigInt->new( _constant(shift) ); };
|
---|
184 |
|
---|
185 | $self->export_to_level(1,$self,@a); # export inf and NaN
|
---|
186 | }
|
---|
187 |
|
---|
188 | sub inf () { Math::BigInt->binf(); }
|
---|
189 | sub NaN () { Math::BigInt->bnan(); }
|
---|
190 |
|
---|
191 | 1;
|
---|
192 |
|
---|
193 | __END__
|
---|
194 |
|
---|
195 | =head1 NAME
|
---|
196 |
|
---|
197 | bigint - Transparent BigInteger support for Perl
|
---|
198 |
|
---|
199 | =head1 SYNOPSIS
|
---|
200 |
|
---|
201 | use bigint;
|
---|
202 |
|
---|
203 | $x = 2 + 4.5,"\n"; # BigInt 6
|
---|
204 | print 2 ** 512,"\n"; # really is what you think it is
|
---|
205 | print inf + 42,"\n"; # inf
|
---|
206 | print NaN * 7,"\n"; # NaN
|
---|
207 |
|
---|
208 | =head1 DESCRIPTION
|
---|
209 |
|
---|
210 | All operators (including basic math operations) are overloaded. Integer
|
---|
211 | constants are created as proper BigInts.
|
---|
212 |
|
---|
213 | Floating point constants are truncated to integer. All results are also
|
---|
214 | truncated.
|
---|
215 |
|
---|
216 | =head2 Options
|
---|
217 |
|
---|
218 | bigint recognizes some options that can be passed while loading it via use.
|
---|
219 | The options can (currently) be either a single letter form, or the long form.
|
---|
220 | The following options exist:
|
---|
221 |
|
---|
222 | =over 2
|
---|
223 |
|
---|
224 | =item a or accuracy
|
---|
225 |
|
---|
226 | This sets the accuracy for all math operations. The argument must be greater
|
---|
227 | than or equal to zero. See Math::BigInt's bround() function for details.
|
---|
228 |
|
---|
229 | perl -Mbigint=a,2 -le 'print 12345+1'
|
---|
230 |
|
---|
231 | =item p or precision
|
---|
232 |
|
---|
233 | This sets the precision for all math operations. The argument can be any
|
---|
234 | integer. Negative values mean a fixed number of digits after the dot, and
|
---|
235 | are <B>ignored</B> since all operations happen in integer space.
|
---|
236 | A positive value rounds to this digit left from the dot. 0 or 1 mean round to
|
---|
237 | integer and are ignore like negative values.
|
---|
238 |
|
---|
239 | See Math::BigInt's bfround() function for details.
|
---|
240 |
|
---|
241 | perl -Mbignum=p,5 -le 'print 123456789+123'
|
---|
242 |
|
---|
243 | =item t or trace
|
---|
244 |
|
---|
245 | This enables a trace mode and is primarily for debugging bigint or
|
---|
246 | Math::BigInt.
|
---|
247 |
|
---|
248 | =item l or lib
|
---|
249 |
|
---|
250 | Load a different math lib, see L<MATH LIBRARY>.
|
---|
251 |
|
---|
252 | perl -Mbigint=l,GMP -e 'print 2 ** 512'
|
---|
253 |
|
---|
254 | Currently there is no way to specify more than one library on the command
|
---|
255 | line. This will be hopefully fixed soon ;)
|
---|
256 |
|
---|
257 | =item v or version
|
---|
258 |
|
---|
259 | This prints out the name and version of all modules used and then exits.
|
---|
260 |
|
---|
261 | perl -Mbigint=v
|
---|
262 |
|
---|
263 | =head2 Math Library
|
---|
264 |
|
---|
265 | Math with the numbers is done (by default) by a module called
|
---|
266 | Math::BigInt::Calc. This is equivalent to saying:
|
---|
267 |
|
---|
268 | use bigint lib => 'Calc';
|
---|
269 |
|
---|
270 | You can change this by using:
|
---|
271 |
|
---|
272 | use bigint lib => 'BitVect';
|
---|
273 |
|
---|
274 | The following would first try to find Math::BigInt::Foo, then
|
---|
275 | Math::BigInt::Bar, and when this also fails, revert to Math::BigInt::Calc:
|
---|
276 |
|
---|
277 | use bigint lib => 'Foo,Math::BigInt::Bar';
|
---|
278 |
|
---|
279 | Please see respective module documentation for further details.
|
---|
280 |
|
---|
281 | =head2 Internal Format
|
---|
282 |
|
---|
283 | The numbers are stored as objects, and their internals might change at anytime,
|
---|
284 | especially between math operations. The objects also might belong to different
|
---|
285 | classes, like Math::BigInt, or Math::BigInt::Lite. Mixing them together, even
|
---|
286 | with normal scalars is not extraordinary, but normal and expected.
|
---|
287 |
|
---|
288 | You should not depend on the internal format, all accesses must go through
|
---|
289 | accessor methods. E.g. looking at $x->{sign} is not a good idea since there
|
---|
290 | is no guaranty that the object in question has such a hash key, nor is a hash
|
---|
291 | underneath at all.
|
---|
292 |
|
---|
293 | =head2 Sign
|
---|
294 |
|
---|
295 | The sign is either '+', '-', 'NaN', '+inf' or '-inf'.
|
---|
296 | You can access it with the sign() method.
|
---|
297 |
|
---|
298 | A sign of 'NaN' is used to represent the result when input arguments are not
|
---|
299 | numbers or as a result of 0/0. '+inf' and '-inf' represent plus respectively
|
---|
300 | minus infinity. You will get '+inf' when dividing a positive number by 0, and
|
---|
301 | '-inf' when dividing any negative number by 0.
|
---|
302 |
|
---|
303 | =head2 Methods
|
---|
304 |
|
---|
305 | Since all numbers are now objects, you can use all functions that are part of
|
---|
306 | the BigInt API. You can only use the bxxx() notation, and not the fxxx()
|
---|
307 | notation, though.
|
---|
308 |
|
---|
309 | =head2 Caveat
|
---|
310 |
|
---|
311 | But a warning is in order. When using the following to make a copy of a number,
|
---|
312 | only a shallow copy will be made.
|
---|
313 |
|
---|
314 | $x = 9; $y = $x;
|
---|
315 | $x = $y = 7;
|
---|
316 |
|
---|
317 | Using the copy or the original with overloaded math is okay, e.g. the
|
---|
318 | following work:
|
---|
319 |
|
---|
320 | $x = 9; $y = $x;
|
---|
321 | print $x + 1, " ", $y,"\n"; # prints 10 9
|
---|
322 |
|
---|
323 | but calling any method that modifies the number directly will result in
|
---|
324 | B<both> the original and the copy beeing destroyed:
|
---|
325 |
|
---|
326 | $x = 9; $y = $x;
|
---|
327 | print $x->badd(1), " ", $y,"\n"; # prints 10 10
|
---|
328 |
|
---|
329 | $x = 9; $y = $x;
|
---|
330 | print $x->binc(1), " ", $y,"\n"; # prints 10 10
|
---|
331 |
|
---|
332 | $x = 9; $y = $x;
|
---|
333 | print $x->bmul(2), " ", $y,"\n"; # prints 18 18
|
---|
334 |
|
---|
335 | Using methods that do not modify, but testthe contents works:
|
---|
336 |
|
---|
337 | $x = 9; $y = $x;
|
---|
338 | $z = 9 if $x->is_zero(); # works fine
|
---|
339 |
|
---|
340 | See the documentation about the copy constructor and C<=> in overload, as
|
---|
341 | well as the documentation in BigInt for further details.
|
---|
342 |
|
---|
343 | =head1 MODULES USED
|
---|
344 |
|
---|
345 | C<bigint> is just a thin wrapper around various modules of the Math::BigInt
|
---|
346 | family. Think of it as the head of the family, who runs the shop, and orders
|
---|
347 | the others to do the work.
|
---|
348 |
|
---|
349 | The following modules are currently used by bigint:
|
---|
350 |
|
---|
351 | Math::BigInt::Lite (for speed, and only if it is loadable)
|
---|
352 | Math::BigInt
|
---|
353 |
|
---|
354 | =head1 EXAMPLES
|
---|
355 |
|
---|
356 | Some cool command line examples to impress the Python crowd ;) You might want
|
---|
357 | to compare them to the results under -Mbignum or -Mbigrat:
|
---|
358 |
|
---|
359 | perl -Mbigint -le 'print sqrt(33)'
|
---|
360 | perl -Mbigint -le 'print 2*255'
|
---|
361 | perl -Mbigint -le 'print 4.5+2*255'
|
---|
362 | perl -Mbigint -le 'print 3/7 + 5/7 + 8/3'
|
---|
363 | perl -Mbigint -le 'print 123->is_odd()'
|
---|
364 | perl -Mbigint -le 'print log(2)'
|
---|
365 | perl -Mbigint -le 'print 2 ** 0.5'
|
---|
366 | perl -Mbigint=a,65 -le 'print 2 ** 0.2'
|
---|
367 |
|
---|
368 | =head1 LICENSE
|
---|
369 |
|
---|
370 | This program is free software; you may redistribute it and/or modify it under
|
---|
371 | the same terms as Perl itself.
|
---|
372 |
|
---|
373 | =head1 SEE ALSO
|
---|
374 |
|
---|
375 | Especially L<bigrat> as in C<perl -Mbigrat -le 'print 1/3+1/4'> and
|
---|
376 | L<bignum> as in C<perl -Mbignum -le 'print sqrt(2)'>.
|
---|
377 |
|
---|
378 | L<Math::BigInt>, L<Math::BigRat> and L<Math::Big> as well
|
---|
379 | as L<Math::BigInt::BitVect>, L<Math::BigInt::Pari> and L<Math::BigInt::GMP>.
|
---|
380 |
|
---|
381 | =head1 AUTHORS
|
---|
382 |
|
---|
383 | (C) by Tels L<http://bloodgate.com/> in early 2002 - 2005.
|
---|
384 |
|
---|
385 | =cut
|
---|