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1 | package bignum; |
2 | require 5.005; |
3 | |
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4 | $VERSION = '0.11'; |
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5 | use Exporter; |
6 | @ISA = qw( Exporter ); |
7 | @EXPORT_OK = qw( ); |
8 | |
9 | use strict; |
10 | |
11 | ############################################################################## |
12 | |
13 | # These are all alike, and thus faked by AUTOLOAD |
14 | |
15 | my @faked = qw/round_mode accuracy precision div_scale/; |
16 | use vars qw/$VERSION $AUTOLOAD $_lite/; # _lite for testsuite |
17 | |
18 | sub AUTOLOAD |
19 | { |
20 | my $name = $AUTOLOAD; |
21 | |
22 | $name =~ s/.*:://; # split package |
23 | no strict 'refs'; |
24 | foreach my $n (@faked) |
25 | { |
26 | if ($n eq $name) |
27 | { |
28 | *{"bignum::$name"} = sub |
29 | { |
30 | my $self = shift; |
31 | no strict 'refs'; |
32 | if (defined $_[0]) |
33 | { |
34 | Math::BigInt->$name($_[0]); |
35 | Math::BigFloat->$name($_[0]); |
36 | } |
37 | return Math::BigInt->$name(); |
38 | }; |
39 | return &$name; |
40 | } |
41 | } |
42 | |
43 | # delayed load of Carp and avoid recursion |
44 | require Carp; |
45 | Carp::croak ("Can't call bignum\-\>$name, not a valid method"); |
46 | } |
47 | |
48 | sub upgrade |
49 | { |
50 | my $self = shift; |
51 | no strict 'refs'; |
52 | # if (defined $_[0]) |
53 | # { |
54 | # $Math::BigInt::upgrade = $_[0]; |
55 | # $Math::BigFloat::upgrade = $_[0]; |
56 | # } |
57 | return $Math::BigInt::upgrade; |
58 | } |
59 | |
60 | sub import |
61 | { |
62 | my $self = shift; |
63 | |
64 | # some defaults |
65 | my $lib = 'Calc'; |
66 | my $upgrade = 'Math::BigFloat'; |
67 | my $downgrade = 'Math::BigInt'; |
68 | |
69 | my @import = ( ':constant' ); # drive it w/ constant |
70 | my @a = @_; my $l = scalar @_; my $j = 0; |
71 | my ($ver,$trace); # version? trace? |
72 | my ($a,$p); # accuracy, precision |
73 | for ( my $i = 0; $i < $l ; $i++,$j++ ) |
74 | { |
75 | if ($_[$i] eq 'upgrade') |
76 | { |
77 | # this causes upgrading |
78 | $upgrade = $_[$i+1]; # or undef to disable |
79 | my $s = 2; $s = 1 if @a-$j < 2; # avoid "can not modify non-existant..." |
80 | splice @a, $j, $s; $j -= $s; $i++; |
81 | } |
82 | elsif ($_[$i] eq 'downgrade') |
83 | { |
84 | # this causes downgrading |
85 | $downgrade = $_[$i+1]; # or undef to disable |
86 | my $s = 2; $s = 1 if @a-$j < 2; # avoid "can not modify non-existant..." |
87 | splice @a, $j, $s; $j -= $s; $i++; |
88 | } |
89 | elsif ($_[$i] =~ /^(l|lib)$/) |
90 | { |
91 | # this causes a different low lib to take care... |
92 | $lib = $_[$i+1] || ''; |
93 | my $s = 2; $s = 1 if @a-$j < 2; # avoid "can not modify non-existant..." |
94 | splice @a, $j, $s; $j -= $s; $i++; |
95 | } |
96 | elsif ($_[$i] =~ /^(a|accuracy)$/) |
97 | { |
98 | $a = $_[$i+1]; |
99 | my $s = 2; $s = 1 if @a-$j < 2; # avoid "can not modify non-existant..." |
100 | splice @a, $j, $s; $j -= $s; $i++; |
101 | } |
102 | elsif ($_[$i] =~ /^(p|precision)$/) |
103 | { |
104 | $p = $_[$i+1]; |
105 | my $s = 2; $s = 1 if @a-$j < 2; # avoid "can not modify non-existant..." |
106 | splice @a, $j, $s; $j -= $s; $i++; |
107 | } |
108 | elsif ($_[$i] =~ /^(v|version)$/) |
109 | { |
110 | $ver = 1; |
111 | splice @a, $j, 1; $j --; |
112 | } |
113 | elsif ($_[$i] =~ /^(t|trace)$/) |
114 | { |
115 | $trace = 1; |
116 | splice @a, $j, 1; $j --; |
117 | } |
118 | else { die "unknown option $_[$i]"; } |
119 | } |
120 | my $class; |
121 | $_lite = 0; # using M::BI::L ? |
122 | if ($trace) |
123 | { |
124 | require Math::BigInt::Trace; $class = 'Math::BigInt::Trace'; |
125 | $upgrade = 'Math::BigFloat::Trace'; |
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126 | } |
127 | else |
128 | { |
129 | # see if we can find Math::BigInt::Lite |
130 | if (!defined $a && !defined $p) # rounding won't work to well |
131 | { |
132 | eval 'require Math::BigInt::Lite;'; |
133 | if ($@ eq '') |
134 | { |
135 | @import = ( ); # :constant in Lite, not MBI |
136 | Math::BigInt::Lite->import( ':constant' ); |
137 | $_lite= 1; # signal okay |
138 | } |
139 | } |
140 | require Math::BigInt if $_lite == 0; # not already loaded? |
141 | $class = 'Math::BigInt'; # regardless of MBIL or not |
142 | } |
143 | # Math::BigInt::Trace or plain Math::BigInt |
144 | $class->import(@import, upgrade => $upgrade, lib => $lib); |
145 | |
146 | if ($trace) |
147 | { |
148 | require Math::BigFloat::Trace; $class = 'Math::BigFloat::Trace'; |
149 | $downgrade = 'Math::BigInt::Trace'; |
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150 | } |
151 | else |
152 | { |
153 | require Math::BigFloat; $class = 'Math::BigFloat'; |
154 | } |
155 | $class->import(':constant','downgrade',$downgrade); |
156 | |
157 | bignum->accuracy($a) if defined $a; |
158 | bignum->precision($p) if defined $p; |
159 | if ($ver) |
160 | { |
161 | print "bignum\t\t\t v$VERSION\n"; |
162 | print "Math::BigInt::Lite\t v$Math::BigInt::Lite::VERSION\n" if $_lite; |
163 | print "Math::BigInt\t\t v$Math::BigInt::VERSION"; |
164 | my $config = Math::BigInt->config(); |
165 | print " lib => $config->{lib} v$config->{lib_version}\n"; |
166 | print "Math::BigFloat\t\t v$Math::BigFloat::VERSION\n"; |
167 | exit; |
168 | } |
169 | } |
170 | |
171 | 1; |
172 | |
173 | __END__ |
174 | |
175 | =head1 NAME |
176 | |
177 | bignum - Transparent BigNumber support for Perl |
178 | |
179 | =head1 SYNOPSIS |
180 | |
181 | use bignum; |
182 | |
183 | $x = 2 + 4.5,"\n"; # BigFloat 6.5 |
184 | print 2 ** 512 * 0.1; # really is what you think it is |
185 | |
186 | =head1 DESCRIPTION |
187 | |
188 | All operators (including basic math operations) are overloaded. Integer and |
189 | floating-point constants are created as proper BigInts or BigFloats, |
190 | respectively. |
191 | |
192 | =head2 OPTIONS |
193 | |
194 | bignum recognizes some options that can be passed while loading it via use. |
195 | The options can (currently) be either a single letter form, or the long form. |
196 | The following options exist: |
197 | |
198 | =over 2 |
199 | |
200 | =item a or accuracy |
201 | |
202 | This sets the accuracy for all math operations. The argument must be greater |
203 | than or equal to zero. See Math::BigInt's bround() function for details. |
204 | |
205 | perl -Mbignum=a,50 -le 'print sqrt(20)' |
206 | |
207 | =item p or precision |
208 | |
209 | This sets the precision for all math operations. The argument can be any |
210 | integer. Negative values mean a fixed number of digits after the dot, while |
211 | a positive value rounds to this digit left from the dot. 0 or 1 mean round to |
212 | integer. See Math::BigInt's bfround() function for details. |
213 | |
214 | perl -Mbignum=p,-50 -le 'print sqrt(20)' |
215 | |
216 | =item t or trace |
217 | |
218 | This enables a trace mode and is primarily for debugging bignum or |
219 | Math::BigInt/Math::BigFloat. |
220 | |
221 | =item l or lib |
222 | |
223 | Load a different math lib, see L<MATH LIBRARY>. |
224 | |
225 | perl -Mbignum=l,GMP -e 'print 2 ** 512' |
226 | |
227 | Currently there is no way to specify more than one library on the command |
228 | line. This will be hopefully fixed soon ;) |
229 | |
230 | =item v or version |
231 | |
232 | This prints out the name and version of all modules used and then exits. |
233 | |
234 | perl -Mbignum=v -e '' |
235 | |
236 | =head2 MATH LIBRARY |
237 | |
238 | Math with the numbers is done (by default) by a module called |
239 | Math::BigInt::Calc. This is equivalent to saying: |
240 | |
241 | use bignum lib => 'Calc'; |
242 | |
243 | You can change this by using: |
244 | |
245 | use bignum lib => 'BitVect'; |
246 | |
247 | The following would first try to find Math::BigInt::Foo, then |
248 | Math::BigInt::Bar, and when this also fails, revert to Math::BigInt::Calc: |
249 | |
250 | use bignum lib => 'Foo,Math::BigInt::Bar'; |
251 | |
252 | Please see respective module documentation for further details. |
253 | |
254 | =head2 INTERNAL FORMAT |
255 | |
256 | The numbers are stored as objects, and their internals might change at anytime, |
257 | especially between math operations. The objects also might belong to different |
258 | classes, like Math::BigInt, or Math::BigFLoat. Mixing them together, even |
259 | with normal scalars is not extraordinary, but normal and expected. |
260 | |
261 | You should not depend on the internal format, all accesses must go through |
262 | accessor methods. E.g. looking at $x->{sign} is not a bright idea since there |
263 | is no guaranty that the object in question has such a hashkey, nor is a hash |
264 | underneath at all. |
265 | |
266 | =head2 SIGN |
267 | |
268 | The sign is either '+', '-', 'NaN', '+inf' or '-inf' and stored seperately. |
269 | You can access it with the sign() method. |
270 | |
271 | A sign of 'NaN' is used to represent the result when input arguments are not |
272 | numbers or as a result of 0/0. '+inf' and '-inf' represent plus respectively |
273 | minus infinity. You will get '+inf' when dividing a positive number by 0, and |
274 | '-inf' when dividing any negative number by 0. |
275 | |
276 | =head2 METHODS |
277 | |
278 | Since all numbers are now objects, you can use all functions that are part of |
279 | the BigInt or BigFloat API. It is wise to use only the bxxx() notation, and not |
280 | the fxxx() notation, though. This makes it possible that the underlying object |
281 | might morph into a different class than BigFloat. |
282 | |
283 | =head1 MODULES USED |
284 | |
285 | C<bignum> is just a thin wrapper around various modules of the Math::BigInt |
286 | family. Think of it as the head of the family, who runs the shop, and orders |
287 | the others to do the work. |
288 | |
289 | The following modules are currently used by bignum: |
290 | |
291 | Math::BigInt::Lite (for speed, and only if it is loadable) |
292 | Math::BigInt |
293 | Math::BigFloat |
294 | |
295 | =head1 EXAMPLES |
296 | |
297 | Some cool command line examples to impress the Python crowd ;) |
298 | |
299 | perl -Mbignum -le 'print sqrt(33)' |
300 | perl -Mbignum -le 'print 2*255' |
301 | perl -Mbignum -le 'print 4.5+2*255' |
302 | perl -Mbignum -le 'print 3/7 + 5/7 + 8/3' |
303 | perl -Mbignum -le 'print 123->is_odd()' |
304 | perl -Mbignum -le 'print log(2)' |
305 | perl -Mbignum -le 'print 2 ** 0.5' |
306 | perl -Mbignum=a,65 -le 'print 2 ** 0.2' |
307 | |
308 | =head1 LICENSE |
309 | |
310 | This program is free software; you may redistribute it and/or modify it under |
311 | the same terms as Perl itself. |
312 | |
313 | =head1 SEE ALSO |
314 | |
315 | Especially L<bigrat> as in C<perl -Mbigrat -le 'print 1/3+1/4'>. |
316 | |
317 | L<Math::BigFloat>, L<Math::BigInt>, L<Math::BigRat> and L<Math::Big> as well |
318 | as L<Math::BigInt::BitVect>, L<Math::BigInt::Pari> and L<Math::BigInt::GMP>. |
319 | |
320 | =head1 AUTHORS |
321 | |
322 | (C) by Tels L<http://bloodgate.com/> in early 2002. |
323 | |
324 | =cut |