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1 | package bigrat; |
2 | require 5.005; |
3 | |
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4 | $VERSION = '0.07'; |
5 | require Exporter; |
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6 | @ISA = qw( Exporter ); |
7 | @EXPORT_OK = qw( ); |
8 | @EXPORT = qw( inf NaN ); |
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9 | |
10 | use strict; |
11 | |
12 | ############################################################################## |
13 | |
14 | # These are all alike, and thus faked by AUTOLOAD |
15 | |
16 | my @faked = qw/round_mode accuracy precision div_scale/; |
17 | use vars qw/$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 $name) |
28 | { |
29 | *{"bigrat::$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($_[0]); |
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37 | return Math::BigRat->$name($_[0]); |
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38 | } |
39 | return Math::BigInt->$name(); |
40 | }; |
41 | return &$name; |
42 | } |
43 | } |
44 | |
45 | # delayed load of Carp and avoid recursion |
46 | require Carp; |
47 | Carp::croak ("Can't call bigrat\-\>$name, not a valid method"); |
48 | } |
49 | |
50 | sub upgrade |
51 | { |
52 | my $self = shift; |
53 | no strict 'refs'; |
54 | # if (defined $_[0]) |
55 | # { |
56 | # $Math::BigInt::upgrade = $_[0]; |
57 | # $Math::BigFloat::upgrade = $_[0]; |
58 | # } |
59 | return $Math::BigInt::upgrade; |
60 | } |
61 | |
62 | sub import |
63 | { |
64 | my $self = shift; |
65 | |
66 | # see also bignum->import() for additional comments |
67 | |
68 | # some defaults |
69 | my $lib = 'Calc'; my $upgrade = 'Math::BigFloat'; |
70 | |
71 | my @import = ( ':constant' ); # drive it w/ constant |
72 | my @a = @_; my $l = scalar @_; my $j = 0; |
73 | my ($a,$p); |
74 | my ($ver,$trace); # version? trace? |
75 | for ( my $i = 0; $i < $l ; $i++,$j++ ) |
76 | { |
77 | if ($_[$i] eq 'upgrade') |
78 | { |
79 | # this causes upgrading |
80 | $upgrade = $_[$i+1]; # or undef to disable |
81 | my $s = 2; $s = 1 if @a-$j < 2; # avoid "can not modify non-existant..." |
82 | splice @a, $j, $s; $j -= $s; |
83 | } |
84 | elsif ($_[$i] =~ /^(l|lib)$/) |
85 | { |
86 | # this causes a different low lib to take care... |
87 | $lib = $_[$i+1] || ''; |
88 | my $s = 2; $s = 1 if @a-$j < 2; # avoid "can not modify non-existant..." |
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89 | splice @a, $j, $s; $j -= $s; $i++; |
90 | } |
91 | elsif ($_[$i] =~ /^(a|accuracy)$/) |
92 | { |
93 | $a = $_[$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; $i++; |
96 | } |
97 | elsif ($_[$i] =~ /^(p|precision)$/) |
98 | { |
99 | $p = $_[$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; $i++; |
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102 | } |
103 | elsif ($_[$i] =~ /^(v|version)$/) |
104 | { |
105 | $ver = 1; |
106 | splice @a, $j, 1; $j --; |
107 | } |
108 | elsif ($_[$i] =~ /^(t|trace)$/) |
109 | { |
110 | $trace = 1; |
111 | splice @a, $j, 1; $j --; |
112 | } |
113 | else |
114 | { |
115 | die ("unknown option $_[$i]"); |
116 | } |
117 | } |
118 | my $class; |
119 | $_lite = 0; # using M::BI::L ? |
120 | if ($trace) |
121 | { |
122 | require Math::BigInt::Trace; $class = 'Math::BigInt::Trace'; |
123 | $upgrade = 'Math::BigFloat::Trace'; |
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124 | } |
125 | else |
126 | { |
127 | # see if we can find Math::BigInt::Lite |
128 | if (!defined $a && !defined $p) # rounding won't work to well |
129 | { |
130 | eval 'require Math::BigInt::Lite;'; |
131 | if ($@ eq '') |
132 | { |
133 | @import = ( ); # :constant in Lite, not MBI |
134 | Math::BigInt::Lite->import( ':constant' ); |
135 | $_lite= 1; # signal okay |
136 | } |
137 | } |
138 | require Math::BigInt if $_lite == 0; # not already loaded? |
139 | $class = 'Math::BigInt'; # regardless of MBIL or not |
140 | } |
141 | # Math::BigInt::Trace or plain Math::BigInt |
142 | $class->import(@import, upgrade => $upgrade, lib => $lib); |
143 | |
144 | require Math::BigFloat; |
145 | Math::BigFloat->import( upgrade => 'Math::BigRat', ':constant' ); |
146 | require Math::BigRat; |
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147 | |
148 | bigrat->accuracy($a) if defined $a; |
149 | bigrat->precision($p) if defined $p; |
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150 | if ($ver) |
151 | { |
152 | print "bigrat\t\t\t v$VERSION\n"; |
153 | print "Math::BigInt::Lite\t v$Math::BigInt::Lite::VERSION\n" if $_lite; |
154 | print "Math::BigInt\t\t v$Math::BigInt::VERSION"; |
155 | my $config = Math::BigInt->config(); |
156 | print " lib => $config->{lib} v$config->{lib_version}\n"; |
157 | print "Math::BigFloat\t\t v$Math::BigFloat::VERSION\n"; |
158 | print "Math::BigRat\t\t v$Math::BigRat::VERSION\n"; |
159 | exit; |
160 | } |
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161 | $self->export_to_level(1,$self,@a); # export inf and NaN |
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162 | } |
163 | |
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164 | sub inf () { Math::BigInt->binf(); } |
165 | sub NaN () { Math::BigInt->bnan(); } |
166 | |
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167 | 1; |
168 | |
169 | __END__ |
170 | |
171 | =head1 NAME |
172 | |
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173 | bigrat - Transparent BigNumber/BigRational support for Perl |
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174 | |
175 | =head1 SYNOPSIS |
176 | |
177 | use bigrat; |
178 | |
179 | $x = 2 + 4.5,"\n"; # BigFloat 6.5 |
180 | print 1/3 + 1/4,"\n"; # produces 7/12 |
181 | |
182 | =head1 DESCRIPTION |
183 | |
184 | All operators (inlcuding basic math operations) are overloaded. Integer and |
185 | floating-point constants are created as proper BigInts or BigFloats, |
186 | respectively. |
187 | |
188 | Other than L<bignum>, this module upgrades to Math::BigRat, meaning that |
189 | instead of 2.5 you will get 2+1/2 as output. |
190 | |
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191 | =head2 Modules Used |
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192 | |
193 | C<bigrat> is just a thin wrapper around various modules of the Math::BigInt |
194 | family. Think of it as the head of the family, who runs the shop, and orders |
195 | the others to do the work. |
196 | |
197 | The following modules are currently used by bignum: |
198 | |
199 | Math::BigInt::Lite (for speed, and only if it is loadable) |
200 | Math::BigInt |
201 | Math::BigFloat |
202 | Math::BigRat |
203 | |
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204 | =head2 Math Library |
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205 | |
206 | Math with the numbers is done (by default) by a module called |
207 | Math::BigInt::Calc. This is equivalent to saying: |
208 | |
209 | use bigrat lib => 'Calc'; |
210 | |
211 | You can change this by using: |
212 | |
213 | use bigrat lib => 'BitVect'; |
214 | |
215 | The following would first try to find Math::BigInt::Foo, then |
216 | Math::BigInt::Bar, and when this also fails, revert to Math::BigInt::Calc: |
217 | |
218 | use bigrat lib => 'Foo,Math::BigInt::Bar'; |
219 | |
220 | Please see respective module documentation for further details. |
221 | |
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222 | =head2 Sign |
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223 | |
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224 | The sign is either '+', '-', 'NaN', '+inf' or '-inf'. |
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225 | |
226 | A sign of 'NaN' is used to represent the result when input arguments are not |
227 | numbers or as a result of 0/0. '+inf' and '-inf' represent plus respectively |
228 | minus infinity. You will get '+inf' when dividing a positive number by 0, and |
229 | '-inf' when dividing any negative number by 0. |
230 | |
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231 | =head2 Methods |
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232 | |
233 | Since all numbers are not objects, you can use all functions that are part of |
234 | the BigInt or BigFloat API. It is wise to use only the bxxx() notation, and not |
235 | the fxxx() notation, though. This makes you independed on the fact that the |
236 | underlying object might morph into a different class than BigFloat. |
237 | |
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238 | =head2 Cavaet |
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239 | |
240 | But a warning is in order. When using the following to make a copy of a number, |
241 | only a shallow copy will be made. |
242 | |
243 | $x = 9; $y = $x; |
244 | $x = $y = 7; |
245 | |
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246 | If you want to make a real copy, use the following: |
247 | |
248 | $y = $x->copy(); |
249 | |
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250 | Using the copy or the original with overloaded math is okay, e.g. the |
251 | following work: |
252 | |
253 | $x = 9; $y = $x; |
254 | print $x + 1, " ", $y,"\n"; # prints 10 9 |
255 | |
256 | but calling any method that modifies the number directly will result in |
257 | B<both> the original and the copy beeing destroyed: |
258 | |
259 | $x = 9; $y = $x; |
260 | print $x->badd(1), " ", $y,"\n"; # prints 10 10 |
261 | |
262 | $x = 9; $y = $x; |
263 | print $x->binc(1), " ", $y,"\n"; # prints 10 10 |
264 | |
265 | $x = 9; $y = $x; |
266 | print $x->bmul(2), " ", $y,"\n"; # prints 18 18 |
267 | |
268 | Using methods that do not modify, but testthe contents works: |
269 | |
270 | $x = 9; $y = $x; |
271 | $z = 9 if $x->is_zero(); # works fine |
272 | |
273 | See the documentation about the copy constructor and C<=> in overload, as |
274 | well as the documentation in BigInt for further details. |
275 | |
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276 | =head2 Options |
277 | |
278 | bignum recognizes some options that can be passed while loading it via use. |
279 | The options can (currently) be either a single letter form, or the long form. |
280 | The following options exist: |
281 | |
282 | =over 2 |
283 | |
284 | =item a or accuracy |
285 | |
286 | This sets the accuracy for all math operations. The argument must be greater |
287 | than or equal to zero. See Math::BigInt's bround() function for details. |
288 | |
289 | perl -Mbigrat=a,50 -le 'print sqrt(20)' |
290 | |
291 | =item p or precision |
292 | |
293 | This sets the precision for all math operations. The argument can be any |
294 | integer. Negative values mean a fixed number of digits after the dot, while |
295 | a positive value rounds to this digit left from the dot. 0 or 1 mean round to |
296 | integer. See Math::BigInt's bfround() function for details. |
297 | |
298 | perl -Mbigrat=p,-50 -le 'print sqrt(20)' |
299 | |
300 | =item t or trace |
301 | |
302 | This enables a trace mode and is primarily for debugging bignum or |
303 | Math::BigInt/Math::BigFloat. |
304 | |
305 | =item l or lib |
306 | |
307 | Load a different math lib, see L<MATH LIBRARY>. |
308 | |
309 | perl -Mbigrat=l,GMP -e 'print 2 ** 512' |
310 | |
311 | Currently there is no way to specify more than one library on the command |
312 | line. This will be hopefully fixed soon ;) |
313 | |
314 | =item v or version |
315 | |
316 | This prints out the name and version of all modules used and then exits. |
317 | |
318 | perl -Mbigrat=v |
319 | |
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320 | =head1 EXAMPLES |
321 | |
322 | perl -Mbigrat -le 'print sqrt(33)' |
323 | perl -Mbigrat -le 'print 2*255' |
324 | perl -Mbigrat -le 'print 4.5+2*255' |
325 | perl -Mbigrat -le 'print 3/7 + 5/7 + 8/3' |
326 | perl -Mbigrat -le 'print 12->is_odd()'; |
327 | |
328 | =head1 LICENSE |
329 | |
330 | This program is free software; you may redistribute it and/or modify it under |
331 | the same terms as Perl itself. |
332 | |
333 | =head1 SEE ALSO |
334 | |
335 | Especially L<bignum>. |
336 | |
337 | L<Math::BigFloat>, L<Math::BigInt>, L<Math::BigRat> and L<Math::Big> as well |
338 | as L<Math::BigInt::BitVect>, L<Math::BigInt::Pari> and L<Math::BigInt::GMP>. |
339 | |
340 | =head1 AUTHORS |
341 | |
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342 | (C) by Tels L<http://bloodgate.com/> in early 2002 - 2005. |
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343 | |
344 | =cut |