Re: Copious warnings from Sys::Syslog
[p5sagit/p5-mst-13.2.git] / lib / Locale / Script.pod
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2=head1 NAME
3
4Locale::Script - ISO codes for script identification (ISO 15924)
5
6=head1 SYNOPSIS
7
8 use Locale::Script;
9 use Locale::Constants;
10
11 $script = code2script('ph'); # 'Phoenician'
12 $code = script2code('Tibetan'); # 'bo'
13 $code3 = script2code('Tibetan',
14 LOCALE_CODE_ALPHA_3); # 'bod'
15 $codeN = script2code('Tibetan',
16 LOCALE_CODE_ALPHA_NUMERIC); # 330
17
18 @codes = all_script_codes();
19 @scripts = all_script_names();
20
21
22=head1 DESCRIPTION
23
24The C<Locale::Script> module provides access to the ISO
25codes for identifying scripts, as defined in ISO 15924.
26For example, Egyptian hieroglyphs are denoted by the two-letter
27code 'eg', the three-letter code 'egy', and the numeric code 050.
28
29You can either access the codes via the conversion routines
30(described below), or with the two functions which return lists
31of all script codes or all script names.
32
33There are three different code sets you can use for identifying
34scripts:
35
36=over 4
37
38=item B<alpha-2>
39
40Two letter codes, such as 'bo' for Tibetan.
41This code set is identified with the symbol C<LOCALE_CODE_ALPHA_2>.
42
43=item B<alpha-3>
44
45Three letter codes, such as 'ell' for Greek.
46This code set is identified with the symbol C<LOCALE_CODE_ALPHA_3>.
47
48=item B<numeric>
49
50Numeric codes, such as 410 for Hiragana.
51This code set is identified with the symbol C<LOCALE_CODE_NUMERIC>.
52
53=back
54
55All of the routines take an optional additional argument
56which specifies the code set to use.
57If not specified, it defaults to the two-letter codes.
58This is partly for backwards compatibility (previous versions
59of Locale modules only supported the alpha-2 codes), and
60partly because they are the most widely used codes.
61
62The alpha-2 and alpha-3 codes are not case-dependent,
63so you can use 'BO', 'Bo', 'bO' or 'bo' for Tibetan.
64When a code is returned by one of the functions in
65this module, it will always be lower-case.
66
67=head2 SPECIAL CODES
68
69The standard defines various special codes.
70
71=over 4
72
73=item *
74
75The standard reserves codes in the ranges B<qa> - B<qt>,
76B<qaa> - B<qat>, and B<900> - B<919>, for private use.
77
78=item *
79
80B<zx>, B<zxx>, and B<997>, are the codes for unwritten languages.
81
82=item *
83
84B<zy>, B<zyy>, and B<998>, are the codes for an undetermined script.
85
86=item *
87
88B<zz>, B<zzz>, and B<999>, are the codes for an uncoded script.
89
90=back
91
92The private codes are not recognised by Locale::Script,
93but the others are.
94
95
96=head1 CONVERSION ROUTINES
97
98There are three conversion routines: C<code2script()>, C<script2code()>,
99and C<script_code2code()>.
100
101=over 4
102
103=item code2script( CODE, [ CODESET ] )
104
105This function takes a script code and returns a string
106which contains the name of the script identified.
107If the code is not a valid script code, as defined by ISO 15924,
108then C<undef> will be returned:
109
110 $script = code2script('cy'); # Cyrillic
111
112=item script2code( STRING, [ CODESET ] )
113
114This function takes a script name and returns the corresponding
115script code, if such exists.
116If the argument could not be identified as a script name,
117then C<undef> will be returned:
118
119 $code = script2code('Gothic', LOCALE_CODE_ALPHA_3);
120 # $code will now be 'gth'
121
122The case of the script name is not important.
123See the section L<KNOWN BUGS AND LIMITATIONS> below.
124
125=item script_code2code( CODE, CODESET, CODESET )
126
127This function takes a script code from one code set,
128and returns the corresponding code from another code set.
129
130 $alpha2 = script_code2code('jwi',
131 LOCALE_CODE_ALPHA_3 => LOCALE_CODE_ALPHA_2);
132 # $alpha2 will now be 'jw' (Javanese)
133
134If the code passed is not a valid script code in
135the first code set, or if there isn't a code for the
136corresponding script in the second code set,
137then C<undef> will be returned.
138
139=back
140
141
142=head1 QUERY ROUTINES
143
144There are two function which can be used to obtain a list of all codes,
145or all script names:
146
147=over 4
148
149=item C<all_script_codes ( [ CODESET ] )>
150
151Returns a list of all two-letter script codes.
152The codes are guaranteed to be all lower-case,
153and not in any particular order.
154
155=item C<all_script_names ( [ CODESET ] )>
156
157Returns a list of all script names for which there is a corresponding
158script code in the specified code set.
159The names are capitalised, and not returned in any particular order.
160
161=back
162
163
164=head1 EXAMPLES
165
166The following example illustrates use of the C<code2script()> function.
167The user is prompted for a script code, and then told the corresponding
168script name:
169
170 $| = 1; # turn off buffering
171
172 print "Enter script code: ";
173 chop($code = <STDIN>);
174 $script = code2script($code, LOCALE_CODE_ALPHA_2);
175 if (defined $script)
176 {
177 print "$code = $script\n";
178 }
179 else
180 {
181 print "'$code' is not a valid script code!\n";
182 }
183
184
185=head1 KNOWN BUGS AND LIMITATIONS
186
187=over 4
188
189=item *
190
191When using C<script2code()>, the script name must currently appear
192exactly as it does in the source of the module. For example,
193
194 script2code('Egyptian hieroglyphs')
195
196will return B<eg>, as expected. But the following will all return C<undef>:
197
198 script2code('hieroglyphs')
199 script2code('Egyptian Hieroglypics')
200
201If there's need for it, a future version could have variants
202for script names.
203
204=item *
205
206In the current implementation, all data is read in when the
207module is loaded, and then held in memory.
208A lazy implementation would be more memory friendly.
209
210=back
211
212=head1 SEE ALSO
213
214=over 4
215
216=item Locale::Language
217
218ISO two letter codes for identification of language (ISO 639).
219
220=item Locale::Currency
221
222ISO three letter codes for identification of currencies
223and funds (ISO 4217).
224
225=item Locale::Country
226
227ISO three letter codes for identification of countries (ISO 3166)
228
229=item ISO 15924
230
231The ISO standard which defines these codes.
232
233=item http://www.evertype.com/standards/iso15924/
234
235Home page for ISO 15924.
236
237
238=back
239
240
241=head1 AUTHOR
242
243Neil Bowers E<lt>neil@bowers.comE<gt>
244
245=head1 COPYRIGHT
246
247Copyright (c) 2002 Neil Bowers.
248
249This module is free software; you can redistribute it and/or
250modify it under the same terms as Perl itself.
251
252=cut
253