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1 | package bigrat; |
2 | require 5.005; |
3 | |
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4 | $VERSION = '0.06'; |
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5 | use Exporter; |
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6 | @ISA = qw( Exporter ); |
7 | @EXPORT_OK = qw( ); |
8 | @EXPORT = qw( inf NaN ); |
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9 | |
10 | use strict; |
11 | |
12 | ############################################################################## |
13 | |
14 | # These are all alike, and thus faked by AUTOLOAD |
15 | |
16 | my @faked = qw/round_mode accuracy precision div_scale/; |
17 | use vars qw/$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..." |
89 | splice @a, $j, $s; $j -= $s; |
90 | } |
91 | elsif ($_[$i] =~ /^(v|version)$/) |
92 | { |
93 | $ver = 1; |
94 | splice @a, $j, 1; $j --; |
95 | } |
96 | elsif ($_[$i] =~ /^(t|trace)$/) |
97 | { |
98 | $trace = 1; |
99 | splice @a, $j, 1; $j --; |
100 | } |
101 | else |
102 | { |
103 | die ("unknown option $_[$i]"); |
104 | } |
105 | } |
106 | my $class; |
107 | $_lite = 0; # using M::BI::L ? |
108 | if ($trace) |
109 | { |
110 | require Math::BigInt::Trace; $class = 'Math::BigInt::Trace'; |
111 | $upgrade = 'Math::BigFloat::Trace'; |
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112 | } |
113 | else |
114 | { |
115 | # see if we can find Math::BigInt::Lite |
116 | if (!defined $a && !defined $p) # rounding won't work to well |
117 | { |
118 | eval 'require Math::BigInt::Lite;'; |
119 | if ($@ eq '') |
120 | { |
121 | @import = ( ); # :constant in Lite, not MBI |
122 | Math::BigInt::Lite->import( ':constant' ); |
123 | $_lite= 1; # signal okay |
124 | } |
125 | } |
126 | require Math::BigInt if $_lite == 0; # not already loaded? |
127 | $class = 'Math::BigInt'; # regardless of MBIL or not |
128 | } |
129 | # Math::BigInt::Trace or plain Math::BigInt |
130 | $class->import(@import, upgrade => $upgrade, lib => $lib); |
131 | |
132 | require Math::BigFloat; |
133 | Math::BigFloat->import( upgrade => 'Math::BigRat', ':constant' ); |
134 | require Math::BigRat; |
135 | if ($ver) |
136 | { |
137 | print "bigrat\t\t\t v$VERSION\n"; |
138 | print "Math::BigInt::Lite\t v$Math::BigInt::Lite::VERSION\n" if $_lite; |
139 | print "Math::BigInt\t\t v$Math::BigInt::VERSION"; |
140 | my $config = Math::BigInt->config(); |
141 | print " lib => $config->{lib} v$config->{lib_version}\n"; |
142 | print "Math::BigFloat\t\t v$Math::BigFloat::VERSION\n"; |
143 | print "Math::BigRat\t\t v$Math::BigRat::VERSION\n"; |
144 | exit; |
145 | } |
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146 | $self->export_to_level(1,$self,@a); # export inf and NaN |
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147 | } |
148 | |
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149 | sub inf () { Math::BigInt->binf(); } |
150 | sub NaN () { Math::BigInt->bnan(); } |
151 | |
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152 | 1; |
153 | |
154 | __END__ |
155 | |
156 | =head1 NAME |
157 | |
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158 | bigrat - Transparent BigNumber/BigRational support for Perl |
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159 | |
160 | =head1 SYNOPSIS |
161 | |
162 | use bigrat; |
163 | |
164 | $x = 2 + 4.5,"\n"; # BigFloat 6.5 |
165 | print 1/3 + 1/4,"\n"; # produces 7/12 |
166 | |
167 | =head1 DESCRIPTION |
168 | |
169 | All operators (inlcuding basic math operations) are overloaded. Integer and |
170 | floating-point constants are created as proper BigInts or BigFloats, |
171 | respectively. |
172 | |
173 | Other than L<bignum>, this module upgrades to Math::BigRat, meaning that |
174 | instead of 2.5 you will get 2+1/2 as output. |
175 | |
176 | =head2 MODULES USED |
177 | |
178 | C<bigrat> is just a thin wrapper around various modules of the Math::BigInt |
179 | family. Think of it as the head of the family, who runs the shop, and orders |
180 | the others to do the work. |
181 | |
182 | The following modules are currently used by bignum: |
183 | |
184 | Math::BigInt::Lite (for speed, and only if it is loadable) |
185 | Math::BigInt |
186 | Math::BigFloat |
187 | Math::BigRat |
188 | |
189 | =head2 MATH LIBRARY |
190 | |
191 | Math with the numbers is done (by default) by a module called |
192 | Math::BigInt::Calc. This is equivalent to saying: |
193 | |
194 | use bigrat lib => 'Calc'; |
195 | |
196 | You can change this by using: |
197 | |
198 | use bigrat lib => 'BitVect'; |
199 | |
200 | The following would first try to find Math::BigInt::Foo, then |
201 | Math::BigInt::Bar, and when this also fails, revert to Math::BigInt::Calc: |
202 | |
203 | use bigrat lib => 'Foo,Math::BigInt::Bar'; |
204 | |
205 | Please see respective module documentation for further details. |
206 | |
207 | =head2 SIGN |
208 | |
209 | The sign is either '+', '-', 'NaN', '+inf' or '-inf' and stored seperately. |
210 | |
211 | A sign of 'NaN' is used to represent the result when input arguments are not |
212 | numbers or as a result of 0/0. '+inf' and '-inf' represent plus respectively |
213 | minus infinity. You will get '+inf' when dividing a positive number by 0, and |
214 | '-inf' when dividing any negative number by 0. |
215 | |
216 | =head2 METHODS |
217 | |
218 | Since all numbers are not objects, you can use all functions that are part of |
219 | the BigInt or BigFloat API. It is wise to use only the bxxx() notation, and not |
220 | the fxxx() notation, though. This makes you independed on the fact that the |
221 | underlying object might morph into a different class than BigFloat. |
222 | |
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223 | =head2 CAVEAT |
224 | |
225 | But a warning is in order. When using the following to make a copy of a number, |
226 | only a shallow copy will be made. |
227 | |
228 | $x = 9; $y = $x; |
229 | $x = $y = 7; |
230 | |
231 | Using the copy or the original with overloaded math is okay, e.g. the |
232 | following work: |
233 | |
234 | $x = 9; $y = $x; |
235 | print $x + 1, " ", $y,"\n"; # prints 10 9 |
236 | |
237 | but calling any method that modifies the number directly will result in |
238 | B<both> the original and the copy beeing destroyed: |
239 | |
240 | $x = 9; $y = $x; |
241 | print $x->badd(1), " ", $y,"\n"; # prints 10 10 |
242 | |
243 | $x = 9; $y = $x; |
244 | print $x->binc(1), " ", $y,"\n"; # prints 10 10 |
245 | |
246 | $x = 9; $y = $x; |
247 | print $x->bmul(2), " ", $y,"\n"; # prints 18 18 |
248 | |
249 | Using methods that do not modify, but testthe contents works: |
250 | |
251 | $x = 9; $y = $x; |
252 | $z = 9 if $x->is_zero(); # works fine |
253 | |
254 | See the documentation about the copy constructor and C<=> in overload, as |
255 | well as the documentation in BigInt for further details. |
256 | |
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257 | =head1 EXAMPLES |
258 | |
259 | perl -Mbigrat -le 'print sqrt(33)' |
260 | perl -Mbigrat -le 'print 2*255' |
261 | perl -Mbigrat -le 'print 4.5+2*255' |
262 | perl -Mbigrat -le 'print 3/7 + 5/7 + 8/3' |
263 | perl -Mbigrat -le 'print 12->is_odd()'; |
264 | |
265 | =head1 LICENSE |
266 | |
267 | This program is free software; you may redistribute it and/or modify it under |
268 | the same terms as Perl itself. |
269 | |
270 | =head1 SEE ALSO |
271 | |
272 | Especially L<bignum>. |
273 | |
274 | L<Math::BigFloat>, L<Math::BigInt>, L<Math::BigRat> and L<Math::Big> as well |
275 | as L<Math::BigInt::BitVect>, L<Math::BigInt::Pari> and L<Math::BigInt::GMP>. |
276 | |
277 | =head1 AUTHORS |
278 | |
279 | (C) by Tels L<http://bloodgate.com/> in early 2002. |
280 | |
281 | =cut |