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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 | $VERSION = '0.10'; |
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5 | require Exporter; |
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6 | @ISA = qw( Exporter ); |
7 | @EXPORT_OK = qw( ); |
8 | @EXPORT = qw( inf NaN ); |
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9 | |
10 | use strict; |
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11 | use overload; |
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12 | |
13 | ############################################################################## |
14 | |
15 | # These are all alike, and thus faked by AUTOLOAD |
16 | |
17 | my @faked = qw/round_mode accuracy precision div_scale/; |
18 | use vars qw/$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 | { |
53 | my $self = shift; |
54 | no strict 'refs'; |
55 | # if (defined $_[0]) |
56 | # { |
57 | # $Math::BigInt::upgrade = $_[0]; |
58 | # $Math::BigFloat::upgrade = $_[0]; |
59 | # } |
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60 | $Math::BigInt::upgrade; |
61 | } |
62 | |
63 | sub _binary_constant |
64 | { |
65 | # this takes a binary/hexadecimal/octal constant string and returns it |
66 | # as string suitable for new. Basically it converts octal to decimal, and |
67 | # passes every thing else unmodified back. |
68 | my $string = shift; |
69 | |
70 | return Math::BigInt->new($string) if $string =~ /^0[bx]/; |
71 | |
72 | # so it must be an octal constant |
73 | Math::BigInt->from_oct($string); |
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74 | } |
75 | |
76 | sub import |
77 | { |
78 | my $self = shift; |
79 | |
80 | # see also bignum->import() for additional comments |
81 | |
82 | # some defaults |
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83 | my $lib = ''; my $lib_kind = 'try'; my $upgrade = 'Math::BigFloat'; |
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84 | |
85 | my @import = ( ':constant' ); # drive it w/ constant |
86 | my @a = @_; my $l = scalar @_; my $j = 0; |
87 | my ($a,$p); |
88 | my ($ver,$trace); # version? trace? |
89 | for ( my $i = 0; $i < $l ; $i++,$j++ ) |
90 | { |
91 | if ($_[$i] eq 'upgrade') |
92 | { |
93 | # this causes upgrading |
94 | $upgrade = $_[$i+1]; # or undef to disable |
95 | my $s = 2; $s = 1 if @a-$j < 2; # avoid "can not modify non-existant..." |
96 | splice @a, $j, $s; $j -= $s; |
97 | } |
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98 | elsif ($_[$i] =~ /^(l|lib|try|only)$/) |
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99 | { |
100 | # this causes a different low lib to take care... |
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101 | $lib_kind = $1; $lib_kind = 'lib' if $lib_kind eq 'l'; |
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102 | $lib = $_[$i+1] || ''; |
103 | my $s = 2; $s = 1 if @a-$j < 2; # avoid "can not modify non-existant..." |
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104 | splice @a, $j, $s; $j -= $s; $i++; |
105 | } |
106 | elsif ($_[$i] =~ /^(a|accuracy)$/) |
107 | { |
108 | $a = $_[$i+1]; |
109 | my $s = 2; $s = 1 if @a-$j < 2; # avoid "can not modify non-existant..." |
110 | splice @a, $j, $s; $j -= $s; $i++; |
111 | } |
112 | elsif ($_[$i] =~ /^(p|precision)$/) |
113 | { |
114 | $p = $_[$i+1]; |
115 | my $s = 2; $s = 1 if @a-$j < 2; # avoid "can not modify non-existant..." |
116 | splice @a, $j, $s; $j -= $s; $i++; |
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117 | } |
118 | elsif ($_[$i] =~ /^(v|version)$/) |
119 | { |
120 | $ver = 1; |
121 | splice @a, $j, 1; $j --; |
122 | } |
123 | elsif ($_[$i] =~ /^(t|trace)$/) |
124 | { |
125 | $trace = 1; |
126 | splice @a, $j, 1; $j --; |
127 | } |
128 | else |
129 | { |
130 | die ("unknown option $_[$i]"); |
131 | } |
132 | } |
133 | my $class; |
134 | $_lite = 0; # using M::BI::L ? |
135 | if ($trace) |
136 | { |
137 | require Math::BigInt::Trace; $class = 'Math::BigInt::Trace'; |
138 | $upgrade = 'Math::BigFloat::Trace'; |
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139 | } |
140 | else |
141 | { |
142 | # see if we can find Math::BigInt::Lite |
143 | if (!defined $a && !defined $p) # rounding won't work to well |
144 | { |
145 | eval 'require Math::BigInt::Lite;'; |
146 | if ($@ eq '') |
147 | { |
148 | @import = ( ); # :constant in Lite, not MBI |
149 | Math::BigInt::Lite->import( ':constant' ); |
150 | $_lite= 1; # signal okay |
151 | } |
152 | } |
153 | require Math::BigInt if $_lite == 0; # not already loaded? |
154 | $class = 'Math::BigInt'; # regardless of MBIL or not |
155 | } |
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156 | push @import, $lib_kind => $lib if $lib ne ''; |
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157 | # Math::BigInt::Trace or plain Math::BigInt |
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158 | $class->import(@import, upgrade => $upgrade); |
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159 | |
160 | require Math::BigFloat; |
161 | Math::BigFloat->import( upgrade => 'Math::BigRat', ':constant' ); |
162 | require Math::BigRat; |
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163 | |
164 | bigrat->accuracy($a) if defined $a; |
165 | bigrat->precision($p) if defined $p; |
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166 | if ($ver) |
167 | { |
168 | print "bigrat\t\t\t v$VERSION\n"; |
169 | print "Math::BigInt::Lite\t v$Math::BigInt::Lite::VERSION\n" if $_lite; |
170 | print "Math::BigInt\t\t v$Math::BigInt::VERSION"; |
171 | my $config = Math::BigInt->config(); |
172 | print " lib => $config->{lib} v$config->{lib_version}\n"; |
173 | print "Math::BigFloat\t\t v$Math::BigFloat::VERSION\n"; |
174 | print "Math::BigRat\t\t v$Math::BigRat::VERSION\n"; |
175 | exit; |
176 | } |
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177 | |
178 | # Take care of octal/hexadecimal constants |
179 | overload::constant binary => sub { _binary_constant(shift) }; |
180 | |
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181 | $self->export_to_level(1,$self,@a); # export inf and NaN |
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182 | } |
183 | |
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184 | sub inf () { Math::BigInt->binf(); } |
185 | sub NaN () { Math::BigInt->bnan(); } |
186 | |
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187 | 1; |
188 | |
189 | __END__ |
190 | |
191 | =head1 NAME |
192 | |
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193 | bigrat - Transparent BigNumber/BigRational support for Perl |
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194 | |
195 | =head1 SYNOPSIS |
196 | |
197 | use bigrat; |
198 | |
199 | $x = 2 + 4.5,"\n"; # BigFloat 6.5 |
200 | print 1/3 + 1/4,"\n"; # produces 7/12 |
201 | |
202 | =head1 DESCRIPTION |
203 | |
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204 | All operators (including basic math operations) are overloaded. Integer and |
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205 | floating-point constants are created as proper BigInts or BigFloats, |
206 | respectively. |
207 | |
208 | Other than L<bignum>, this module upgrades to Math::BigRat, meaning that |
209 | instead of 2.5 you will get 2+1/2 as output. |
210 | |
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211 | =head2 Modules Used |
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212 | |
213 | C<bigrat> is just a thin wrapper around various modules of the Math::BigInt |
214 | family. Think of it as the head of the family, who runs the shop, and orders |
215 | the others to do the work. |
216 | |
217 | The following modules are currently used by bignum: |
218 | |
219 | Math::BigInt::Lite (for speed, and only if it is loadable) |
220 | Math::BigInt |
221 | Math::BigFloat |
222 | Math::BigRat |
223 | |
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224 | =head2 Math Library |
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225 | |
226 | Math with the numbers is done (by default) by a module called |
227 | Math::BigInt::Calc. This is equivalent to saying: |
228 | |
229 | use bigrat lib => 'Calc'; |
230 | |
231 | You can change this by using: |
232 | |
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233 | use bignum lib => 'GMP'; |
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234 | |
235 | The following would first try to find Math::BigInt::Foo, then |
236 | Math::BigInt::Bar, and when this also fails, revert to Math::BigInt::Calc: |
237 | |
238 | use bigrat lib => 'Foo,Math::BigInt::Bar'; |
239 | |
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240 | Using C<lib> warns if none of the specified libraries can be found and |
241 | L<Math::BigInt> did fall back to one of the default libraries. |
242 | To supress this warning, use C<try> instead: |
243 | |
244 | use bignum try => 'GMP'; |
245 | |
246 | If you want the code to die instead of falling back, use C<only> instead: |
247 | |
248 | use bignum only => 'GMP'; |
249 | |
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250 | Please see respective module documentation for further details. |
251 | |
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252 | =head2 Sign |
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253 | |
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254 | The sign is either '+', '-', 'NaN', '+inf' or '-inf'. |
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255 | |
256 | A sign of 'NaN' is used to represent the result when input arguments are not |
257 | numbers or as a result of 0/0. '+inf' and '-inf' represent plus respectively |
258 | minus infinity. You will get '+inf' when dividing a positive number by 0, and |
259 | '-inf' when dividing any negative number by 0. |
260 | |
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261 | =head2 Methods |
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262 | |
263 | Since all numbers are not objects, you can use all functions that are part of |
264 | the BigInt or BigFloat API. It is wise to use only the bxxx() notation, and not |
265 | the fxxx() notation, though. This makes you independed on the fact that the |
266 | underlying object might morph into a different class than BigFloat. |
267 | |
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268 | =over 2 |
269 | |
270 | =item inf() |
271 | |
272 | A shortcut to return Math::BigInt->binf(). Useful because Perl does not always |
273 | handle bareword C<inf> properly. |
274 | |
275 | =item NaN() |
276 | |
277 | A shortcut to return Math::BigInt->bnan(). Useful because Perl does not always |
278 | handle bareword C<NaN> properly. |
279 | |
280 | =item upgrade() |
281 | |
282 | Return the class that numbers are upgraded to, is in fact returning |
283 | C<$Math::BigInt::upgrade>. |
284 | |
285 | =back |
286 | |
287 | =head2 MATH LIBRARY |
288 | |
289 | Math with the numbers is done (by default) by a module called |
290 | |
291 | =head2 Cavaet |
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292 | |
293 | But a warning is in order. When using the following to make a copy of a number, |
294 | only a shallow copy will be made. |
295 | |
296 | $x = 9; $y = $x; |
297 | $x = $y = 7; |
298 | |
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299 | If you want to make a real copy, use the following: |
300 | |
301 | $y = $x->copy(); |
302 | |
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303 | Using the copy or the original with overloaded math is okay, e.g. the |
304 | following work: |
305 | |
306 | $x = 9; $y = $x; |
307 | print $x + 1, " ", $y,"\n"; # prints 10 9 |
308 | |
309 | but calling any method that modifies the number directly will result in |
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310 | B<both> the original and the copy being destroyed: |
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311 | |
312 | $x = 9; $y = $x; |
313 | print $x->badd(1), " ", $y,"\n"; # prints 10 10 |
314 | |
315 | $x = 9; $y = $x; |
316 | print $x->binc(1), " ", $y,"\n"; # prints 10 10 |
317 | |
318 | $x = 9; $y = $x; |
319 | print $x->bmul(2), " ", $y,"\n"; # prints 18 18 |
320 | |
321 | Using methods that do not modify, but testthe contents works: |
322 | |
323 | $x = 9; $y = $x; |
324 | $z = 9 if $x->is_zero(); # works fine |
325 | |
326 | See the documentation about the copy constructor and C<=> in overload, as |
327 | well as the documentation in BigInt for further details. |
328 | |
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329 | =head2 Options |
330 | |
331 | bignum recognizes some options that can be passed while loading it via use. |
332 | The options can (currently) be either a single letter form, or the long form. |
333 | The following options exist: |
334 | |
335 | =over 2 |
336 | |
337 | =item a or accuracy |
338 | |
339 | This sets the accuracy for all math operations. The argument must be greater |
340 | than or equal to zero. See Math::BigInt's bround() function for details. |
341 | |
342 | perl -Mbigrat=a,50 -le 'print sqrt(20)' |
343 | |
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344 | Note that setting precision and accurary at the same time is not possible. |
345 | |
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346 | =item p or precision |
347 | |
348 | This sets the precision for all math operations. The argument can be any |
349 | integer. Negative values mean a fixed number of digits after the dot, while |
350 | a positive value rounds to this digit left from the dot. 0 or 1 mean round to |
351 | integer. See Math::BigInt's bfround() function for details. |
352 | |
353 | perl -Mbigrat=p,-50 -le 'print sqrt(20)' |
354 | |
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355 | Note that setting precision and accurary at the same time is not possible. |
356 | |
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357 | =item t or trace |
358 | |
359 | This enables a trace mode and is primarily for debugging bignum or |
360 | Math::BigInt/Math::BigFloat. |
361 | |
362 | =item l or lib |
363 | |
364 | Load a different math lib, see L<MATH LIBRARY>. |
365 | |
366 | perl -Mbigrat=l,GMP -e 'print 2 ** 512' |
367 | |
368 | Currently there is no way to specify more than one library on the command |
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369 | line. This means the following does not work: |
370 | |
371 | perl -Mbignum=l,GMP,Pari -e 'print 2 ** 512' |
372 | |
373 | This will be hopefully fixed soon ;) |
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374 | |
375 | =item v or version |
376 | |
377 | This prints out the name and version of all modules used and then exits. |
378 | |
379 | perl -Mbigrat=v |
380 | |
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381 | =back |
382 | |
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383 | =head1 EXAMPLES |
384 | |
385 | perl -Mbigrat -le 'print sqrt(33)' |
386 | perl -Mbigrat -le 'print 2*255' |
387 | perl -Mbigrat -le 'print 4.5+2*255' |
388 | perl -Mbigrat -le 'print 3/7 + 5/7 + 8/3' |
389 | perl -Mbigrat -le 'print 12->is_odd()'; |
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390 | perl -Mbignum=l,GMP -le 'print 7 ** 7777' |
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391 | |
392 | =head1 LICENSE |
393 | |
394 | This program is free software; you may redistribute it and/or modify it under |
395 | the same terms as Perl itself. |
396 | |
397 | =head1 SEE ALSO |
398 | |
399 | Especially L<bignum>. |
400 | |
401 | L<Math::BigFloat>, L<Math::BigInt>, L<Math::BigRat> and L<Math::Big> as well |
402 | as L<Math::BigInt::BitVect>, L<Math::BigInt::Pari> and L<Math::BigInt::GMP>. |
403 | |
404 | =head1 AUTHORS |
405 | |
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406 | (C) by Tels L<http://bloodgate.com/> in early 2002 - 2007. |
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407 | |
408 | =cut |