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1 | package bignum; |
2 | require 5.005; |
3 | |
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4 | $VERSION = '0.12'; |
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5 | use Exporter; |
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6 | @EXPORT_OK = qw( ); |
7 | @EXPORT = qw( inf NaN ); |
8 | @ISA = qw( Exporter ); |
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9 | |
10 | use strict; |
11 | |
12 | ############################################################################## |
13 | |
14 | # These are all alike, and thus faked by AUTOLOAD |
15 | |
16 | my @faked = qw/round_mode accuracy precision div_scale/; |
17 | use vars qw/$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 $name) |
28 | { |
29 | *{"bignum::$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 &$name; |
41 | } |
42 | } |
43 | |
44 | # delayed load of Carp and avoid recursion |
45 | require Carp; |
46 | Carp::croak ("Can't call bignum\-\>$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 | # some defaults |
66 | my $lib = 'Calc'; |
67 | my $upgrade = 'Math::BigFloat'; |
68 | my $downgrade = 'Math::BigInt'; |
69 | |
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++ ) |
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; $i++; |
82 | } |
83 | elsif ($_[$i] eq 'downgrade') |
84 | { |
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; $i++; |
89 | } |
90 | elsif ($_[$i] =~ /^(l|lib)$/) |
91 | { |
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; $i++; |
96 | } |
97 | elsif ($_[$i] =~ /^(a|accuracy)$/) |
98 | { |
99 | $a = $_[$i+1]; |
100 | my $s = 2; $s = 1 if @a-$j < 2; # avoid "can not modify non-existant..." |
101 | splice @a, $j, $s; $j -= $s; $i++; |
102 | } |
103 | elsif ($_[$i] =~ /^(p|precision)$/) |
104 | { |
105 | $p = $_[$i+1]; |
106 | my $s = 2; $s = 1 if @a-$j < 2; # avoid "can not modify non-existant..." |
107 | splice @a, $j, $s; $j -= $s; $i++; |
108 | } |
109 | elsif ($_[$i] =~ /^(v|version)$/) |
110 | { |
111 | $ver = 1; |
112 | splice @a, $j, 1; $j --; |
113 | } |
114 | elsif ($_[$i] =~ /^(t|trace)$/) |
115 | { |
116 | $trace = 1; |
117 | splice @a, $j, 1; $j --; |
118 | } |
119 | else { die "unknown option $_[$i]"; } |
120 | } |
121 | my $class; |
122 | $_lite = 0; # using M::BI::L ? |
123 | if ($trace) |
124 | { |
125 | require Math::BigInt::Trace; $class = 'Math::BigInt::Trace'; |
126 | $upgrade = 'Math::BigFloat::Trace'; |
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127 | } |
128 | else |
129 | { |
130 | # see if we can find Math::BigInt::Lite |
131 | if (!defined $a && !defined $p) # rounding won't work to well |
132 | { |
133 | eval 'require Math::BigInt::Lite;'; |
134 | if ($@ eq '') |
135 | { |
136 | @import = ( ); # :constant in Lite, not MBI |
137 | Math::BigInt::Lite->import( ':constant' ); |
138 | $_lite= 1; # signal okay |
139 | } |
140 | } |
141 | require Math::BigInt if $_lite == 0; # not already loaded? |
142 | $class = 'Math::BigInt'; # regardless of MBIL or not |
143 | } |
144 | # Math::BigInt::Trace or plain Math::BigInt |
145 | $class->import(@import, upgrade => $upgrade, lib => $lib); |
146 | |
147 | if ($trace) |
148 | { |
149 | require Math::BigFloat::Trace; $class = 'Math::BigFloat::Trace'; |
150 | $downgrade = 'Math::BigInt::Trace'; |
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151 | } |
152 | else |
153 | { |
154 | require Math::BigFloat; $class = 'Math::BigFloat'; |
155 | } |
156 | $class->import(':constant','downgrade',$downgrade); |
157 | |
158 | bignum->accuracy($a) if defined $a; |
159 | bignum->precision($p) if defined $p; |
160 | if ($ver) |
161 | { |
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"; |
168 | exit; |
169 | } |
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170 | $self->export_to_level(1,$self,@a); # export inf and NaN |
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171 | } |
172 | |
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173 | sub inf () { Math::BigInt->binf(); } |
174 | sub NaN () { Math::BigInt->bnan(); } |
175 | |
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176 | 1; |
177 | |
178 | __END__ |
179 | |
180 | =head1 NAME |
181 | |
182 | bignum - Transparent BigNumber support for Perl |
183 | |
184 | =head1 SYNOPSIS |
185 | |
186 | use bignum; |
187 | |
188 | $x = 2 + 4.5,"\n"; # BigFloat 6.5 |
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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 |
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192 | |
193 | =head1 DESCRIPTION |
194 | |
195 | All operators (including basic math operations) are overloaded. Integer and |
196 | floating-point constants are created as proper BigInts or BigFloats, |
197 | respectively. |
198 | |
199 | =head2 OPTIONS |
200 | |
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: |
204 | |
205 | =over 2 |
206 | |
207 | =item a or accuracy |
208 | |
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. |
211 | |
212 | perl -Mbignum=a,50 -le 'print sqrt(20)' |
213 | |
214 | =item p or precision |
215 | |
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. |
220 | |
221 | perl -Mbignum=p,-50 -le 'print sqrt(20)' |
222 | |
223 | =item t or trace |
224 | |
225 | This enables a trace mode and is primarily for debugging bignum or |
226 | Math::BigInt/Math::BigFloat. |
227 | |
228 | =item l or lib |
229 | |
230 | Load a different math lib, see L<MATH LIBRARY>. |
231 | |
232 | perl -Mbignum=l,GMP -e 'print 2 ** 512' |
233 | |
234 | Currently there is no way to specify more than one library on the command |
235 | line. This will be hopefully fixed soon ;) |
236 | |
237 | =item v or version |
238 | |
239 | This prints out the name and version of all modules used and then exits. |
240 | |
241 | perl -Mbignum=v -e '' |
242 | |
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243 | =head2 METHODS |
244 | |
245 | Beside import() and AUTOLOAD() there are only a few other methods. |
246 | |
247 | =over 2 |
248 | |
249 | =item inf() |
250 | |
251 | A shortcut to return Math::BigInt->binf(). Usefull because Perl does not always |
252 | handle bareword C<inf> properly. |
253 | |
254 | =item NaN() |
255 | |
256 | A shortcut to return Math::BigInt->bnan(). Usefull because Perl does not always |
257 | handle bareword C<NaN> properly. |
258 | |
259 | =item upgrade() |
260 | |
261 | Return the class that numbers are upgraded to, is in fact returning |
262 | C<$Math::BigInt::upgrade>. |
263 | |
264 | =back |
265 | |
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266 | =head2 MATH LIBRARY |
267 | |
268 | Math with the numbers is done (by default) by a module called |
269 | Math::BigInt::Calc. This is equivalent to saying: |
270 | |
271 | use bignum lib => 'Calc'; |
272 | |
273 | You can change this by using: |
274 | |
275 | use bignum lib => 'BitVect'; |
276 | |
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: |
279 | |
280 | use bignum lib => 'Foo,Math::BigInt::Bar'; |
281 | |
282 | Please see respective module documentation for further details. |
283 | |
284 | =head2 INTERNAL FORMAT |
285 | |
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. |
290 | |
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 |
294 | underneath at all. |
295 | |
296 | =head2 SIGN |
297 | |
298 | The sign is either '+', '-', 'NaN', '+inf' or '-inf' and stored seperately. |
299 | You can access it with the sign() method. |
300 | |
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. |
305 | |
306 | =head2 METHODS |
307 | |
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. |
312 | |
313 | =head1 MODULES USED |
314 | |
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. |
318 | |
319 | The following modules are currently used by bignum: |
320 | |
321 | Math::BigInt::Lite (for speed, and only if it is loadable) |
322 | Math::BigInt |
323 | Math::BigFloat |
324 | |
325 | =head1 EXAMPLES |
326 | |
327 | Some cool command line examples to impress the Python crowd ;) |
328 | |
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' |
337 | |
338 | =head1 LICENSE |
339 | |
340 | This program is free software; you may redistribute it and/or modify it under |
341 | the same terms as Perl itself. |
342 | |
343 | =head1 SEE ALSO |
344 | |
345 | Especially L<bigrat> as in C<perl -Mbigrat -le 'print 1/3+1/4'>. |
346 | |
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>. |
349 | |
350 | =head1 AUTHORS |
351 | |
352 | (C) by Tels L<http://bloodgate.com/> in early 2002. |
353 | |
354 | =cut |