Commit | Line | Data |
126f3c5f |
1 | package bigint; |
2 | require 5.005; |
3 | |
4 | $VERSION = '0.02'; |
5 | use Exporter; |
6 | @ISA = qw( Exporter ); |
7 | @EXPORT_OK = qw( ); |
8 | |
9 | use strict; |
10 | use overload; |
11 | |
12 | ############################################################################## |
13 | |
14 | # These are all alike, and thus faked by AUTOLOAD |
15 | |
16 | my @faked = qw/round_mode accuracy precision div_scale/; |
17 | use vars qw/$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 $name) |
28 | { |
29 | *{"bigint::$name"} = sub |
30 | { |
31 | my $self = shift; |
32 | no strict 'refs'; |
33 | if (defined $_[0]) |
34 | { |
35 | Math::BigInt->$name($_[0]); |
36 | } |
37 | return Math::BigInt->$name(); |
38 | }; |
39 | return &$name; |
40 | } |
41 | } |
42 | |
43 | # delayed load of Carp and avoid recursion |
44 | require Carp; |
45 | Carp::croak ("Can't call bigint\-\>$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 | # } |
56 | return $Math::BigInt::upgrade; |
57 | } |
58 | |
59 | sub _constant |
60 | { |
61 | # this takes a floating point constant string and returns it truncated to |
62 | # integer. For instance, '4.5' => '4', '1.234e2' => '123' etc |
63 | my $float = shift; |
64 | |
65 | # some simple cases first |
66 | return $float if ($float =~ /^[+-]?[0-9]+$/); # '+123','-1','0' etc |
67 | return $float |
68 | if ($float =~ /^[+-]?[0-9]+\.?[eE]\+?[0-9]+$/); # 123e2, 123.e+2 |
69 | return '0' if ($float =~ /^[+-]?[0]*\.[0-9]+$/); # .2, 0.2, -.1 |
70 | if ($float =~ /^[+-]?[0-9]+\.[0-9]*$/) # 1., 1.23, -1.2 etc |
71 | { |
72 | $float =~ s/\..*//; |
73 | return $float; |
74 | } |
75 | my ($mis,$miv,$mfv,$es,$ev) = Math::BigInt::_split(\$float); |
76 | return $float if !defined $mis; # doesn't look like a number to me |
77 | my $ec = int($$ev); |
78 | my $sign = $$mis; $sign = '' if $sign eq '+'; |
79 | if ($$es eq '-') |
80 | { |
81 | # ignore fraction part entirely |
82 | if ($ec >= length($$miv)) # 123.23E-4 |
83 | { |
84 | return '0'; |
85 | } |
86 | return $sign . substr ($$miv,0,length($$miv)-$ec); # 1234.45E-2 = 12 |
87 | } |
88 | # xE+y |
89 | if ($ec >= length($$mfv)) |
90 | { |
91 | $ec -= length($$mfv); |
92 | return $sign.$$miv.$$mfv if $ec == 0; # 123.45E+2 => 12345 |
93 | return $sign.$$miv.$$mfv.'E'.$ec; # 123.45e+3 => 12345e1 |
94 | } |
95 | $mfv = substr($$mfv,0,$ec); |
96 | return $sign.$$miv.$mfv; # 123.45e+1 => 1234 |
97 | } |
98 | |
99 | sub import |
100 | { |
101 | my $self = shift; |
102 | |
103 | # some defaults |
104 | my $lib = 'Calc'; |
105 | |
106 | my @import = ( ':constant' ); # drive it w/ constant |
107 | my @a = @_; my $l = scalar @_; my $j = 0; |
108 | my ($ver,$trace); # version? trace? |
109 | my ($a,$p); # accuracy, precision |
110 | for ( my $i = 0; $i < $l ; $i++,$j++ ) |
111 | { |
112 | if ($_[$i] =~ /^(l|lib)$/) |
113 | { |
114 | # this causes a different low lib to take care... |
115 | $lib = $_[$i+1] || ''; |
116 | my $s = 2; $s = 1 if @a-$j < 2; # avoid "can not modify non-existant..." |
117 | splice @a, $j, $s; $j -= $s; $i++; |
118 | } |
119 | elsif ($_[$i] =~ /^(a|accuracy)$/) |
120 | { |
121 | $a = $_[$i+1]; |
122 | my $s = 2; $s = 1 if @a-$j < 2; # avoid "can not modify non-existant..." |
123 | splice @a, $j, $s; $j -= $s; $i++; |
124 | } |
125 | elsif ($_[$i] =~ /^(p|precision)$/) |
126 | { |
127 | $p = $_[$i+1]; |
128 | my $s = 2; $s = 1 if @a-$j < 2; # avoid "can not modify non-existant..." |
129 | splice @a, $j, $s; $j -= $s; $i++; |
130 | } |
131 | elsif ($_[$i] =~ /^(v|version)$/) |
132 | { |
133 | $ver = 1; |
134 | splice @a, $j, 1; $j --; |
135 | } |
136 | elsif ($_[$i] =~ /^(t|trace)$/) |
137 | { |
138 | $trace = 1; |
139 | splice @a, $j, 1; $j --; |
140 | } |
141 | else { die "unknown option $_[$i]"; } |
142 | } |
143 | my $class; |
144 | $_lite = 0; # using M::BI::L ? |
145 | if ($trace) |
146 | { |
147 | require Math::BigInt::Trace; $class = 'Math::BigInt::Trace'; |
126f3c5f |
148 | } |
149 | else |
150 | { |
151 | # see if we can find Math::BigInt::Lite |
152 | if (!defined $a && !defined $p) # rounding won't work to well |
153 | { |
154 | eval 'require Math::BigInt::Lite;'; |
155 | if ($@ eq '') |
156 | { |
157 | @import = ( ); # :constant in Lite, not MBI |
158 | Math::BigInt::Lite->import( ':constant' ); |
159 | $_lite= 1; # signal okay |
160 | } |
161 | } |
162 | require Math::BigInt if $_lite == 0; # not already loaded? |
163 | $class = 'Math::BigInt'; # regardless of MBIL or not |
164 | } |
165 | # Math::BigInt::Trace or plain Math::BigInt |
166 | $class->import(@import, lib => $lib); |
167 | |
168 | bigint->accuracy($a) if defined $a; |
169 | bigint->precision($p) if defined $p; |
170 | if ($ver) |
171 | { |
172 | print "bigint\t\t\t v$VERSION\n"; |
173 | print "Math::BigInt::Lite\t v$Math::BigInt::Lite::VERSION\n" if $_lite; |
174 | print "Math::BigInt\t\t v$Math::BigInt::VERSION"; |
175 | my $config = Math::BigInt->config(); |
176 | print " lib => $config->{lib} v$config->{lib_version}\n"; |
177 | exit; |
178 | } |
179 | # we take care of floating point constants, since BigFloat isn't available |
180 | # and BigInt doesn't like them: |
181 | overload::constant float => sub { Math::BigInt->new( _constant(shift) ); }; |
182 | } |
183 | |
184 | 1; |
185 | |
186 | __END__ |
187 | |
188 | =head1 NAME |
189 | |
190 | bigint - Transparent big integer support for Perl |
191 | |
192 | =head1 SYNOPSIS |
193 | |
194 | use bignt; |
195 | |
196 | $x = 2 + 4.5,"\n"; # BigInt 6 |
197 | print 2 ** 512; # really is what you think it is |
198 | |
199 | =head1 DESCRIPTION |
200 | |
201 | All operators (including basic math operations) are overloaded. Integer |
202 | constants are created as proper BigInts. |
203 | |
204 | Floating point constants are truncated to integer. All results are also |
205 | trunctaed. |
206 | |
207 | =head2 OPTIONS |
208 | |
209 | bigint recognizes some options that can be passed while loading it via use. |
210 | The options can (currently) be either a single letter form, or the long form. |
211 | The following options exist: |
212 | |
213 | =over 2 |
214 | |
215 | =item a or accuracy |
216 | |
217 | This sets the accuracy for all math operations. The argument must be greater |
218 | than or equal to zero. See Math::BigInt's bround() function for details. |
219 | |
220 | perl -Mbigint=a,2 -le 'print 12345+1' |
221 | |
222 | =item p or precision |
223 | |
224 | This sets the precision for all math operations. The argument can be any |
225 | integer. Negative values mean a fixed number of digits after the dot, and |
226 | are <B>ignored</B> since all operations happen in integer space. |
227 | A positive value rounds to this digit left from the dot. 0 or 1 mean round to |
228 | integer and are ignore like negative values. |
229 | |
230 | See Math::BigInt's bfround() function for details. |
231 | |
232 | perl -Mbignum=p,5 -le 'print 123456789+123' |
233 | |
234 | =item t or trace |
235 | |
236 | This enables a trace mode and is primarily for debugging bigint or |
237 | Math::BigInt. |
238 | |
239 | =item l or lib |
240 | |
241 | Load a different math lib, see L<MATH LIBRARY>. |
242 | |
243 | perl -Mbigint=l,GMP -e 'print 2 ** 512' |
244 | |
245 | Currently there is no way to specify more than one library on the command |
246 | line. This will be hopefully fixed soon ;) |
247 | |
248 | =item v or version |
249 | |
250 | This prints out the name and version of all modules used and then exits. |
251 | |
252 | perl -Mbigint=v -e '' |
253 | |
254 | =head2 MATH LIBRARY |
255 | |
256 | Math with the numbers is done (by default) by a module called |
257 | Math::BigInt::Calc. This is equivalent to saying: |
258 | |
259 | use bigint lib => 'Calc'; |
260 | |
261 | You can change this by using: |
262 | |
263 | use bigint lib => 'BitVect'; |
264 | |
265 | The following would first try to find Math::BigInt::Foo, then |
266 | Math::BigInt::Bar, and when this also fails, revert to Math::BigInt::Calc: |
267 | |
268 | use bigint lib => 'Foo,Math::BigInt::Bar'; |
269 | |
270 | Please see respective module documentation for further details. |
271 | |
272 | =head2 INTERNAL FORMAT |
273 | |
274 | The numbers are stored as objects, and their internals might change at anytime, |
275 | especially between math operations. The objects also might belong to different |
276 | classes, like Math::BigInt, or Math::BigInt::Lite. Mixing them together, even |
277 | with normal scalars is not extraordinary, but normal and expected. |
278 | |
279 | You should not depend on the internal format, all accesses must go through |
280 | accessor methods. E.g. looking at $x->{sign} is not a bright idea since there |
281 | is no guaranty that the object in question has such a hash key, nor is a hash |
282 | underneath at all. |
283 | |
284 | =head2 SIGN |
285 | |
286 | The sign is either '+', '-', 'NaN', '+inf' or '-inf' and stored seperately. |
287 | You can access it with the sign() method. |
288 | |
289 | A sign of 'NaN' is used to represent the result when input arguments are not |
290 | numbers or as a result of 0/0. '+inf' and '-inf' represent plus respectively |
291 | minus infinity. You will get '+inf' when dividing a positive number by 0, and |
292 | '-inf' when dividing any negative number by 0. |
293 | |
294 | =head2 METHODS |
295 | |
296 | Since all numbers are now objects, you can use all functions that are part of |
297 | the BigInt API. You can only use the bxxx() notation, and not the fxxx() |
298 | notation, though. |
299 | |
300 | =head1 MODULES USED |
301 | |
302 | C<bigint> is just a thin wrapper around various modules of the Math::BigInt |
303 | family. Think of it as the head of the family, who runs the shop, and orders |
304 | the others to do the work. |
305 | |
306 | The following modules are currently used by bigint: |
307 | |
308 | Math::BigInt::Lite (for speed, and only if it is loadable) |
309 | Math::BigInt |
310 | |
311 | =head1 EXAMPLES |
312 | |
313 | Some cool command line examples to impress the Python crowd ;) You might want |
314 | to compare them to the results under -Mbignum or -Mbigrat: |
315 | |
316 | perl -Mbigint -le 'print sqrt(33)' |
317 | perl -Mbigint -le 'print 2*255' |
318 | perl -Mbigint -le 'print 4.5+2*255' |
319 | perl -Mbigint -le 'print 3/7 + 5/7 + 8/3' |
320 | perl -Mbigint -le 'print 123->is_odd()' |
321 | perl -Mbigint -le 'print log(2)' |
322 | perl -Mbigint -le 'print 2 ** 0.5' |
323 | perl -Mbigint=a,65 -le 'print 2 ** 0.2' |
324 | |
325 | =head1 LICENSE |
326 | |
327 | This program is free software; you may redistribute it and/or modify it under |
328 | the same terms as Perl itself. |
329 | |
330 | =head1 SEE ALSO |
331 | |
332 | Especially L<bigrat> as in C<perl -Mbigrat -le 'print 1/3+1/4'> and |
333 | L<bignum> as in C<perl -Mbignum -le 'print sqrt(2)'>. |
334 | |
335 | L<Math::BigInt>, L<Math::BigRat> and L<Math::Big> as well |
336 | as L<Math::BigInt::BitVect>, L<Math::BigInt::Pari> and L<Math::BigInt::GMP>. |
337 | |
338 | =head1 AUTHORS |
339 | |
340 | (C) by Tels L<http://bloodgate.com/> in early 2002. |
341 | |
342 | =cut |