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1 | package bigrat; |
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2 | use 5.006002; |
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3 | |
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4 | $VERSION = '0.22'; |
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5 | require Exporter; |
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6 | @ISA = qw( Exporter ); |
7 | @EXPORT_OK = qw( ); |
8 | @EXPORT = qw( inf NaN ); |
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9 | |
10 | use strict; |
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11 | use overload; |
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12 | |
13 | ############################################################################## |
14 | |
15 | # These are all alike, and thus faked by AUTOLOAD |
16 | |
17 | my @faked = qw/round_mode accuracy precision div_scale/; |
18 | use vars qw/$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 $name) |
29 | { |
30 | *{"bigrat::$name"} = sub |
31 | { |
32 | my $self = shift; |
33 | no strict 'refs'; |
34 | if (defined $_[0]) |
35 | { |
36 | Math::BigInt->$name($_[0]); |
37 | Math::BigFloat->$name($_[0]); |
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38 | return Math::BigRat->$name($_[0]); |
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39 | } |
40 | return Math::BigInt->$name(); |
41 | }; |
42 | return &$name; |
43 | } |
44 | } |
45 | |
46 | # delayed load of Carp and avoid recursion |
47 | require Carp; |
48 | Carp::croak ("Can't call bigrat\-\>$name, not a valid method"); |
49 | } |
50 | |
51 | sub upgrade |
52 | { |
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53 | $Math::BigInt::upgrade; |
54 | } |
55 | |
56 | sub _binary_constant |
57 | { |
58 | # this takes a binary/hexadecimal/octal constant string and returns it |
59 | # as string suitable for new. Basically it converts octal to decimal, and |
60 | # passes every thing else unmodified back. |
61 | my $string = shift; |
62 | |
63 | return Math::BigInt->new($string) if $string =~ /^0[bx]/; |
64 | |
65 | # so it must be an octal constant |
66 | Math::BigInt->from_oct($string); |
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67 | } |
68 | |
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69 | sub unimport |
70 | { |
71 | $^H{bigrat} = undef; # no longer in effect |
72 | overload::remove_constant('binary','','float','','integer'); |
73 | } |
74 | |
75 | sub in_effect |
76 | { |
77 | my $level = shift || 0; |
78 | my $hinthash = (caller($level))[10]; |
79 | $hinthash->{bigrat}; |
80 | } |
81 | |
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82 | sub import |
83 | { |
84 | my $self = shift; |
85 | |
86 | # see also bignum->import() for additional comments |
87 | |
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88 | $^H{bigrat} = 1; # we are in effect |
89 | |
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90 | # some defaults |
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91 | my $lib = ''; my $lib_kind = 'try'; my $upgrade = 'Math::BigFloat'; |
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92 | |
93 | my @import = ( ':constant' ); # drive it w/ constant |
94 | my @a = @_; my $l = scalar @_; my $j = 0; |
95 | my ($a,$p); |
96 | my ($ver,$trace); # version? trace? |
97 | for ( my $i = 0; $i < $l ; $i++,$j++ ) |
98 | { |
99 | if ($_[$i] eq 'upgrade') |
100 | { |
101 | # this causes upgrading |
102 | $upgrade = $_[$i+1]; # or undef to disable |
103 | my $s = 2; $s = 1 if @a-$j < 2; # avoid "can not modify non-existant..." |
104 | splice @a, $j, $s; $j -= $s; |
105 | } |
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106 | elsif ($_[$i] =~ /^(l|lib|try|only)$/) |
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107 | { |
108 | # this causes a different low lib to take care... |
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109 | $lib_kind = $1; $lib_kind = 'lib' if $lib_kind eq 'l'; |
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110 | $lib = $_[$i+1] || ''; |
111 | my $s = 2; $s = 1 if @a-$j < 2; # avoid "can not modify non-existant..." |
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112 | splice @a, $j, $s; $j -= $s; $i++; |
113 | } |
114 | elsif ($_[$i] =~ /^(a|accuracy)$/) |
115 | { |
116 | $a = $_[$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; $i++; |
119 | } |
120 | elsif ($_[$i] =~ /^(p|precision)$/) |
121 | { |
122 | $p = $_[$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; $i++; |
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125 | } |
126 | elsif ($_[$i] =~ /^(v|version)$/) |
127 | { |
128 | $ver = 1; |
129 | splice @a, $j, 1; $j --; |
130 | } |
131 | elsif ($_[$i] =~ /^(t|trace)$/) |
132 | { |
133 | $trace = 1; |
134 | splice @a, $j, 1; $j --; |
135 | } |
136 | else |
137 | { |
138 | die ("unknown option $_[$i]"); |
139 | } |
140 | } |
141 | my $class; |
142 | $_lite = 0; # using M::BI::L ? |
143 | if ($trace) |
144 | { |
145 | require Math::BigInt::Trace; $class = 'Math::BigInt::Trace'; |
146 | $upgrade = 'Math::BigFloat::Trace'; |
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147 | } |
148 | else |
149 | { |
150 | # see if we can find Math::BigInt::Lite |
151 | if (!defined $a && !defined $p) # rounding won't work to well |
152 | { |
153 | eval 'require Math::BigInt::Lite;'; |
154 | if ($@ eq '') |
155 | { |
156 | @import = ( ); # :constant in Lite, not MBI |
157 | Math::BigInt::Lite->import( ':constant' ); |
158 | $_lite= 1; # signal okay |
159 | } |
160 | } |
161 | require Math::BigInt if $_lite == 0; # not already loaded? |
162 | $class = 'Math::BigInt'; # regardless of MBIL or not |
163 | } |
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164 | push @import, $lib_kind => $lib if $lib ne ''; |
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165 | # Math::BigInt::Trace or plain Math::BigInt |
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166 | $class->import(@import, upgrade => $upgrade); |
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167 | |
168 | require Math::BigFloat; |
169 | Math::BigFloat->import( upgrade => 'Math::BigRat', ':constant' ); |
170 | require Math::BigRat; |
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171 | |
172 | bigrat->accuracy($a) if defined $a; |
173 | bigrat->precision($p) if defined $p; |
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174 | if ($ver) |
175 | { |
176 | print "bigrat\t\t\t v$VERSION\n"; |
177 | print "Math::BigInt::Lite\t v$Math::BigInt::Lite::VERSION\n" if $_lite; |
178 | print "Math::BigInt\t\t v$Math::BigInt::VERSION"; |
179 | my $config = Math::BigInt->config(); |
180 | print " lib => $config->{lib} v$config->{lib_version}\n"; |
181 | print "Math::BigFloat\t\t v$Math::BigFloat::VERSION\n"; |
182 | print "Math::BigRat\t\t v$Math::BigRat::VERSION\n"; |
183 | exit; |
184 | } |
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185 | |
186 | # Take care of octal/hexadecimal constants |
187 | overload::constant binary => sub { _binary_constant(shift) }; |
188 | |
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189 | # if another big* was already loaded: |
190 | my ($package) = caller(); |
191 | |
192 | no strict 'refs'; |
193 | if (!defined *{"${package}::inf"}) |
194 | { |
195 | $self->export_to_level(1,$self,@a); # export inf and NaN |
196 | } |
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197 | } |
198 | |
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199 | sub inf () { Math::BigInt->binf(); } |
200 | sub NaN () { Math::BigInt->bnan(); } |
201 | |
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202 | 1; |
203 | |
204 | __END__ |
205 | |
206 | =head1 NAME |
207 | |
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208 | bigrat - Transparent BigNumber/BigRational support for Perl |
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209 | |
210 | =head1 SYNOPSIS |
211 | |
212 | use bigrat; |
213 | |
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214 | print 2 + 4.5,"\n"; # BigFloat 6.5 |
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215 | print 1/3 + 1/4,"\n"; # produces 7/12 |
216 | |
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217 | { |
218 | no bigrat; |
219 | print 1/3,"\n"; # 0.33333... |
220 | } |
221 | |
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222 | =head1 DESCRIPTION |
223 | |
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224 | All operators (including basic math operations) are overloaded. Integer and |
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225 | floating-point constants are created as proper BigInts or BigFloats, |
226 | respectively. |
227 | |
228 | Other than L<bignum>, this module upgrades to Math::BigRat, meaning that |
229 | instead of 2.5 you will get 2+1/2 as output. |
230 | |
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231 | =head2 Modules Used |
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232 | |
233 | C<bigrat> is just a thin wrapper around various modules of the Math::BigInt |
234 | family. Think of it as the head of the family, who runs the shop, and orders |
235 | the others to do the work. |
236 | |
237 | The following modules are currently used by bignum: |
238 | |
239 | Math::BigInt::Lite (for speed, and only if it is loadable) |
240 | Math::BigInt |
241 | Math::BigFloat |
242 | Math::BigRat |
243 | |
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244 | =head2 Math Library |
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245 | |
246 | Math with the numbers is done (by default) by a module called |
247 | Math::BigInt::Calc. This is equivalent to saying: |
248 | |
249 | use bigrat lib => 'Calc'; |
250 | |
251 | You can change this by using: |
252 | |
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253 | use bignum lib => 'GMP'; |
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254 | |
255 | The following would first try to find Math::BigInt::Foo, then |
256 | Math::BigInt::Bar, and when this also fails, revert to Math::BigInt::Calc: |
257 | |
258 | use bigrat lib => 'Foo,Math::BigInt::Bar'; |
259 | |
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260 | Using C<lib> warns if none of the specified libraries can be found and |
261 | L<Math::BigInt> did fall back to one of the default libraries. |
262 | To supress this warning, use C<try> instead: |
263 | |
264 | use bignum try => 'GMP'; |
265 | |
266 | If you want the code to die instead of falling back, use C<only> instead: |
267 | |
268 | use bignum only => 'GMP'; |
269 | |
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270 | Please see respective module documentation for further details. |
271 | |
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272 | =head2 Sign |
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273 | |
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274 | The sign is either '+', '-', 'NaN', '+inf' or '-inf'. |
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275 | |
276 | A sign of 'NaN' is used to represent the result when input arguments are not |
277 | numbers or as a result of 0/0. '+inf' and '-inf' represent plus respectively |
278 | minus infinity. You will get '+inf' when dividing a positive number by 0, and |
279 | '-inf' when dividing any negative number by 0. |
280 | |
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281 | =head2 Methods |
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282 | |
283 | Since all numbers are not objects, you can use all functions that are part of |
284 | the BigInt or BigFloat API. It is wise to use only the bxxx() notation, and not |
285 | the fxxx() notation, though. This makes you independed on the fact that the |
286 | underlying object might morph into a different class than BigFloat. |
287 | |
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288 | =over 2 |
289 | |
290 | =item inf() |
291 | |
292 | A shortcut to return Math::BigInt->binf(). Useful because Perl does not always |
293 | handle bareword C<inf> properly. |
294 | |
295 | =item NaN() |
296 | |
297 | A shortcut to return Math::BigInt->bnan(). Useful because Perl does not always |
298 | handle bareword C<NaN> properly. |
299 | |
300 | =item upgrade() |
301 | |
302 | Return the class that numbers are upgraded to, is in fact returning |
303 | C<$Math::BigInt::upgrade>. |
304 | |
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305 | =item in_effect() |
306 | |
307 | use bigrat; |
308 | |
309 | print "in effect\n" if bigrat::in_effect; # true |
310 | { |
311 | no bigrat; |
312 | print "in effect\n" if bigrat::in_effect; # false |
313 | } |
314 | |
315 | Returns true or false if C<bigrat> is in effect in the current scope. |
316 | |
317 | This method only works on Perl v5.9.4 or later. |
318 | |
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319 | =back |
320 | |
321 | =head2 MATH LIBRARY |
322 | |
323 | Math with the numbers is done (by default) by a module called |
324 | |
325 | =head2 Cavaet |
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326 | |
327 | But a warning is in order. When using the following to make a copy of a number, |
328 | only a shallow copy will be made. |
329 | |
330 | $x = 9; $y = $x; |
331 | $x = $y = 7; |
332 | |
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333 | If you want to make a real copy, use the following: |
334 | |
335 | $y = $x->copy(); |
336 | |
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337 | Using the copy or the original with overloaded math is okay, e.g. the |
338 | following work: |
339 | |
340 | $x = 9; $y = $x; |
341 | print $x + 1, " ", $y,"\n"; # prints 10 9 |
342 | |
343 | but calling any method that modifies the number directly will result in |
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344 | B<both> the original and the copy being destroyed: |
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345 | |
346 | $x = 9; $y = $x; |
347 | print $x->badd(1), " ", $y,"\n"; # prints 10 10 |
348 | |
349 | $x = 9; $y = $x; |
350 | print $x->binc(1), " ", $y,"\n"; # prints 10 10 |
351 | |
352 | $x = 9; $y = $x; |
353 | print $x->bmul(2), " ", $y,"\n"; # prints 18 18 |
354 | |
355 | Using methods that do not modify, but testthe contents works: |
356 | |
357 | $x = 9; $y = $x; |
358 | $z = 9 if $x->is_zero(); # works fine |
359 | |
360 | See the documentation about the copy constructor and C<=> in overload, as |
361 | well as the documentation in BigInt for further details. |
362 | |
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363 | =head2 Options |
364 | |
365 | bignum recognizes some options that can be passed while loading it via use. |
366 | The options can (currently) be either a single letter form, or the long form. |
367 | The following options exist: |
368 | |
369 | =over 2 |
370 | |
371 | =item a or accuracy |
372 | |
373 | This sets the accuracy for all math operations. The argument must be greater |
374 | than or equal to zero. See Math::BigInt's bround() function for details. |
375 | |
376 | perl -Mbigrat=a,50 -le 'print sqrt(20)' |
377 | |
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378 | Note that setting precision and accurary at the same time is not possible. |
379 | |
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380 | =item p or precision |
381 | |
382 | This sets the precision for all math operations. The argument can be any |
383 | integer. Negative values mean a fixed number of digits after the dot, while |
384 | a positive value rounds to this digit left from the dot. 0 or 1 mean round to |
385 | integer. See Math::BigInt's bfround() function for details. |
386 | |
387 | perl -Mbigrat=p,-50 -le 'print sqrt(20)' |
388 | |
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389 | Note that setting precision and accurary at the same time is not possible. |
390 | |
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391 | =item t or trace |
392 | |
393 | This enables a trace mode and is primarily for debugging bignum or |
394 | Math::BigInt/Math::BigFloat. |
395 | |
396 | =item l or lib |
397 | |
398 | Load a different math lib, see L<MATH LIBRARY>. |
399 | |
400 | perl -Mbigrat=l,GMP -e 'print 2 ** 512' |
401 | |
402 | Currently there is no way to specify more than one library on the command |
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403 | line. This means the following does not work: |
404 | |
405 | perl -Mbignum=l,GMP,Pari -e 'print 2 ** 512' |
406 | |
407 | This will be hopefully fixed soon ;) |
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408 | |
409 | =item v or version |
410 | |
411 | This prints out the name and version of all modules used and then exits. |
412 | |
413 | perl -Mbigrat=v |
414 | |
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415 | =back |
416 | |
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417 | =head1 EXAMPLES |
418 | |
419 | perl -Mbigrat -le 'print sqrt(33)' |
420 | perl -Mbigrat -le 'print 2*255' |
421 | perl -Mbigrat -le 'print 4.5+2*255' |
422 | perl -Mbigrat -le 'print 3/7 + 5/7 + 8/3' |
423 | perl -Mbigrat -le 'print 12->is_odd()'; |
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424 | perl -Mbignum=l,GMP -le 'print 7 ** 7777' |
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425 | |
426 | =head1 LICENSE |
427 | |
428 | This program is free software; you may redistribute it and/or modify it under |
429 | the same terms as Perl itself. |
430 | |
431 | =head1 SEE ALSO |
432 | |
433 | Especially L<bignum>. |
434 | |
435 | L<Math::BigFloat>, L<Math::BigInt>, L<Math::BigRat> and L<Math::Big> as well |
436 | as L<Math::BigInt::BitVect>, L<Math::BigInt::Pari> and L<Math::BigInt::GMP>. |
437 | |
438 | =head1 AUTHORS |
439 | |
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440 | (C) by Tels L<http://bloodgate.com/> in early 2002 - 2007. |
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441 | |
442 | =cut |