Commit | Line | Data |
---|---|---|
423cee85 | 1 | package charnames; |
b177ca84 JF |
2 | use strict; |
3 | use warnings; | |
51cf30b6 | 4 | use File::Spec; |
bd5c3bd9 | 5 | our $VERSION = '1.05'; |
b75c8c73 | 6 | |
d5448623 | 7 | use bytes (); # for $bytes::hint_bits |
423cee85 | 8 | |
52ea3e69 JH |
9 | my %alias1 = ( |
10 | # Icky 3.2 names with parentheses. | |
11 | 'LINE FEED' => 'LINE FEED (LF)', | |
12 | 'FORM FEED' => 'FORM FEED (FF)', | |
13 | 'CARRIAGE RETURN' => 'CARRIAGE RETURN (CR)', | |
14 | 'NEXT LINE' => 'NEXT LINE (NEL)', | |
15 | # Convenience. | |
16 | 'LF' => 'LINE FEED (LF)', | |
17 | 'FF' => 'FORM FEED (FF)', | |
eb380778 | 18 | 'CR' => 'CARRIAGE RETURN (CR)', |
51e9e896 | 19 | 'NEL' => 'NEXT LINE (NEL)', |
24b5d5cc JH |
20 | # More convenience. For futher convencience, |
21 | # it is suggested some way using using the NamesList | |
22 | # aliases is implemented. | |
23 | 'ZWNJ' => 'ZERO WIDTH NON-JOINER', | |
24 | 'ZWJ' => 'ZERO WIDTH JOINER', | |
52ea3e69 JH |
25 | 'BOM' => 'BYTE ORDER MARK', |
26 | ); | |
27 | ||
28 | my %alias2 = ( | |
29 | # Pre-3.2 compatibility (only for the first 256 characters). | |
30 | 'HORIZONTAL TABULATION' => 'CHARACTER TABULATION', | |
31 | 'VERTICAL TABULATION' => 'LINE TABULATION', | |
32 | 'FILE SEPARATOR' => 'INFORMATION SEPARATOR FOUR', | |
33 | 'GROUP SEPARATOR' => 'INFORMATION SEPARATOR THREE', | |
34 | 'RECORD SEPARATOR' => 'INFORMATION SEPARATOR TWO', | |
35 | 'UNIT SEPARATOR' => 'INFORMATION SEPARATOR ONE', | |
36 | 'PARTIAL LINE DOWN' => 'PARTIAL LINE FORWARD', | |
37 | 'PARTIAL LINE UP' => 'PARTIAL LINE BACKWARD', | |
38 | ); | |
39 | ||
35c0985d MB |
40 | my %alias3 = ( |
41 | # User defined aliasses. Even more convenient :) | |
42 | ); | |
423cee85 JH |
43 | my $txt; |
44 | ||
8878f897 T |
45 | sub croak |
46 | { | |
47 | require Carp; goto &Carp::croak; | |
48 | } # croak | |
49 | ||
50 | sub carp | |
51 | { | |
52 | require Carp; goto &Carp::carp; | |
53 | } # carp | |
54 | ||
35c0985d MB |
55 | sub alias (@) |
56 | { | |
57 | @_ or return %alias3; | |
58 | my $alias = ref $_[0] ? $_[0] : { @_ }; | |
59 | @alias3{keys %$alias} = values %$alias; | |
60 | } # alias | |
61 | ||
62 | sub alias_file ($) | |
63 | { | |
51cf30b6 MB |
64 | my ($arg, $file) = @_; |
65 | if (-f $arg && File::Spec->file_name_is_absolute ($arg)) { | |
66 | $file = $arg; | |
67 | } | |
68 | elsif ($arg =~ m/^\w+$/) { | |
69 | $file = "unicore/${arg}_alias.pl"; | |
70 | } | |
71 | else { | |
72 | croak "Charnames alias files can only have identifier characters"; | |
73 | } | |
35c0985d | 74 | if (my @alias = do $file) { |
51cf30b6 MB |
75 | @alias == 1 && !defined $alias[0] and |
76 | croak "$file cannot be used as alias file for charnames"; | |
77 | @alias % 2 and | |
78 | croak "$file did not return a (valid) list of alias pairs"; | |
35c0985d MB |
79 | alias (@alias); |
80 | return (1); | |
81 | } | |
82 | 0; | |
83 | } # alias_file | |
84 | ||
423cee85 | 85 | # This is not optimized in any way yet |
b177ca84 JF |
86 | sub charnames |
87 | { | |
88 | my $name = shift; | |
89 | ||
52ea3e69 | 90 | if (exists $alias1{$name}) { |
35c0985d | 91 | $name = $alias1{$name}; |
52ea3e69 | 92 | } |
35c0985d MB |
93 | elsif (exists $alias2{$name}) { |
94 | require warnings; | |
95 | warnings::warnif('deprecated', qq{Unicode character name "$name" is deprecated, use "$alias2{$name}" instead}); | |
96 | $name = $alias2{$name}; | |
97 | } | |
98 | elsif (exists $alias3{$name}) { | |
99 | $name = $alias3{$name}; | |
52ea3e69 | 100 | } |
b177ca84 | 101 | |
52ea3e69 | 102 | my $ord; |
423cee85 | 103 | my @off; |
52ea3e69 JH |
104 | my $fname; |
105 | ||
106 | if ($name eq "BYTE ORDER MARK") { | |
35c0985d MB |
107 | $fname = $name; |
108 | $ord = 0xFEFF; | |
52ea3e69 | 109 | } else { |
35c0985d MB |
110 | ## Suck in the code/name list as a big string. |
111 | ## Lines look like: | |
112 | ## "0052\t\tLATIN CAPITAL LETTER R\n" | |
113 | $txt = do "unicore/Name.pl" unless $txt; | |
114 | ||
115 | ## @off will hold the index into the code/name string of the start and | |
116 | ## end of the name as we find it. | |
117 | ||
a6d05634 | 118 | ## If :full, look for the name exactly |
35c0985d MB |
119 | if ($^H{charnames_full} and $txt =~ /\t\t\Q$name\E$/m) { |
120 | @off = ($-[0], $+[0]); | |
121 | } | |
122 | ||
123 | ## If we didn't get above, and :short allowed, look for the short name. | |
124 | ## The short name is like "greek:Sigma" | |
125 | unless (@off) { | |
126 | if ($^H{charnames_short} and $name =~ /^(.+?):(.+)/s) { | |
127 | my ($script, $cname) = ($1, $2); | |
128 | my $case = $cname =~ /[[:upper:]]/ ? "CAPITAL" : "SMALL"; | |
129 | if ($txt =~ m/\t\t\U$script\E (?:$case )?LETTER \U\Q$cname\E$/m) { | |
52ea3e69 | 130 | @off = ($-[0], $+[0]); |
35c0985d | 131 | } |
423cee85 | 132 | } |
35c0985d | 133 | } |
b177ca84 | 134 | |
35c0985d MB |
135 | ## If we still don't have it, check for the name among the loaded |
136 | ## scripts. | |
137 | if (not @off) { | |
138 | my $case = $name =~ /[[:upper:]]/ ? "CAPITAL" : "SMALL"; | |
139 | for my $script (@{$^H{charnames_scripts}}) { | |
140 | if ($txt =~ m/\t\t$script (?:$case )?LETTER \U\Q$name\E$/m) { | |
141 | @off = ($-[0], $+[0]); | |
142 | last; | |
143 | } | |
52ea3e69 | 144 | } |
35c0985d MB |
145 | } |
146 | ||
147 | ## If we don't have it by now, give up. | |
148 | unless (@off) { | |
149 | carp "Unknown charname '$name'"; | |
150 | return "\x{FFFD}"; | |
151 | } | |
152 | ||
153 | ## | |
154 | ## Now know where in the string the name starts. | |
155 | ## The code, in hex, is before that. | |
156 | ## | |
157 | ## The code can be 4-6 characters long, so we've got to sort of | |
158 | ## go look for it, just after the newline that comes before $off[0]. | |
159 | ## | |
160 | ## This would be much easier if unicore/Name.pl had info in | |
161 | ## a name/code order, instead of code/name order. | |
162 | ## | |
163 | ## The +1 after the rindex() is to skip past the newline we're finding, | |
164 | ## or, if the rindex() fails, to put us to an offset of zero. | |
165 | ## | |
166 | my $hexstart = rindex($txt, "\n", $off[0]) + 1; | |
167 | ||
168 | ## we know where it starts, so turn into number - | |
169 | ## the ordinal for the char. | |
170 | $ord = hex substr($txt, $hexstart, $off[0] - $hexstart); | |
423cee85 | 171 | } |
b177ca84 | 172 | |
d5448623 | 173 | if ($^H & $bytes::hint_bits) { # "use bytes" in effect? |
8058d7ab | 174 | use bytes; |
d41ff1b8 | 175 | return chr $ord if $ord <= 255; |
f0175764 | 176 | my $hex = sprintf "%04x", $ord; |
52ea3e69 | 177 | if (not defined $fname) { |
35c0985d | 178 | $fname = substr $txt, $off[0] + 2, $off[1] - $off[0] - 2; |
52ea3e69 | 179 | } |
f0175764 | 180 | croak "Character 0x$hex with name '$fname' is above 0xFF"; |
423cee85 | 181 | } |
f0175764 | 182 | |
52ea3e69 | 183 | no warnings 'utf8'; # allow even illegal characters |
bfa383d6 | 184 | return pack "U", $ord; |
35c0985d | 185 | } # charnames |
423cee85 | 186 | |
b177ca84 JF |
187 | sub import |
188 | { | |
189 | shift; ## ignore class name | |
190 | ||
35c0985d MB |
191 | if (not @_) { |
192 | carp("`use charnames' needs explicit imports list"); | |
b177ca84 | 193 | } |
423cee85 | 194 | $^H{charnames} = \&charnames ; |
b177ca84 JF |
195 | |
196 | ## | |
197 | ## fill %h keys with our @_ args. | |
198 | ## | |
35c0985d | 199 | my ($promote, %h, @args) = (0); |
e5c3f898 MG |
200 | while (my $arg = shift) { |
201 | if ($arg eq ":alias") { | |
51cf30b6 MB |
202 | @_ or |
203 | croak ":alias needs an argument in charnames"; | |
35c0985d MB |
204 | my $alias = shift; |
205 | if (ref $alias) { | |
206 | ref $alias eq "HASH" or | |
51cf30b6 | 207 | croak "Only HASH reference supported as argument to :alias"; |
35c0985d MB |
208 | alias ($alias); |
209 | next; | |
210 | } | |
51cf30b6 MB |
211 | if ($alias =~ m{:(\w+)$}) { |
212 | $1 eq "full" || $1 eq "short" and | |
213 | croak ":alias cannot use existing pragma :$1 (reversed order?)"; | |
214 | alias_file ($1) and $promote = 1; | |
215 | next; | |
35c0985d | 216 | } |
51cf30b6 MB |
217 | alias_file ($alias); |
218 | next; | |
219 | } | |
e5c3f898 MG |
220 | if (substr($arg, 0, 1) eq ':' and ! ($arg eq ":full" || $arg eq ":short")) { |
221 | warn "unsupported special '$arg' in charnames"; | |
51cf30b6 | 222 | next; |
35c0985d | 223 | } |
e5c3f898 | 224 | push @args, $arg; |
35c0985d MB |
225 | } |
226 | @args == 0 && $promote and @args = (":full"); | |
227 | @h{@args} = (1) x @args; | |
b177ca84 | 228 | |
423cee85 JH |
229 | $^H{charnames_full} = delete $h{':full'}; |
230 | $^H{charnames_short} = delete $h{':short'}; | |
231 | $^H{charnames_scripts} = [map uc, keys %h]; | |
b177ca84 JF |
232 | |
233 | ## | |
234 | ## If utf8? warnings are enabled, and some scripts were given, | |
235 | ## see if at least we can find one letter of each script. | |
236 | ## | |
35c0985d MB |
237 | if (warnings::enabled('utf8') && @{$^H{charnames_scripts}}) { |
238 | $txt = do "unicore/Name.pl" unless $txt; | |
239 | ||
240 | for my $script (@{$^H{charnames_scripts}}) { | |
241 | if (not $txt =~ m/\t\t$script (?:CAPITAL |SMALL )?LETTER /) { | |
242 | warnings::warn('utf8', "No such script: '$script'"); | |
b177ca84 | 243 | } |
35c0985d | 244 | } |
bd62941a | 245 | } |
35c0985d | 246 | } # import |
423cee85 | 247 | |
4e2cda5d JH |
248 | my %viacode; |
249 | ||
b177ca84 JF |
250 | sub viacode |
251 | { | |
35c0985d MB |
252 | if (@_ != 1) { |
253 | carp "charnames::viacode() expects one argument"; | |
bd5c3bd9 | 254 | return; |
35c0985d | 255 | } |
f0175764 | 256 | |
35c0985d | 257 | my $arg = shift; |
b177ca84 | 258 | |
bd5c3bd9 T |
259 | # this comes actually from Unicode::UCD, where it is the named |
260 | # function _getcode (), but it avoids the overhead of loading it | |
35c0985d | 261 | my $hex; |
bd5c3bd9 | 262 | if ($arg =~ /^[1-9]\d*$/) { |
35c0985d | 263 | $hex = sprintf "%04X", $arg; |
bd5c3bd9 T |
264 | } elsif ($arg =~ /^(?:[Uu]\+|0[xX])?([[:xdigit:]]+)$/) { |
265 | $hex = $1; | |
35c0985d MB |
266 | } else { |
267 | carp("unexpected arg \"$arg\" to charnames::viacode()"); | |
268 | return; | |
269 | } | |
b177ca84 | 270 | |
bd5c3bd9 T |
271 | # checking the length first is slightly faster |
272 | if (length($hex) > 5 && hex($hex) > 0x10FFFF) { | |
9b5be9b5 | 273 | carp "Unicode characters only allocated up to U+10FFFF (you asked for U+$hex)"; |
35c0985d MB |
274 | return; |
275 | } | |
f0175764 | 276 | |
35c0985d | 277 | return $viacode{$hex} if exists $viacode{$hex}; |
4e2cda5d | 278 | |
35c0985d | 279 | $txt = do "unicore/Name.pl" unless $txt; |
b177ca84 | 280 | |
bd5c3bd9 T |
281 | return unless $txt =~ m/^$hex\t\t(.+)/m; |
282 | ||
283 | $viacode{$hex} = $1; | |
35c0985d | 284 | } # viacode |
daf0d493 | 285 | |
4e2cda5d JH |
286 | my %vianame; |
287 | ||
daf0d493 JH |
288 | sub vianame |
289 | { | |
35c0985d MB |
290 | if (@_ != 1) { |
291 | carp "charnames::vianame() expects one name argument"; | |
292 | return () | |
293 | } | |
daf0d493 | 294 | |
35c0985d | 295 | my $arg = shift; |
daf0d493 | 296 | |
35c0985d | 297 | return chr hex $1 if $arg =~ /^U\+([0-9a-fA-F]+)$/; |
dbc0d4f2 | 298 | |
35c0985d | 299 | return $vianame{$arg} if exists $vianame{$arg}; |
4e2cda5d | 300 | |
35c0985d | 301 | $txt = do "unicore/Name.pl" unless $txt; |
daf0d493 | 302 | |
35c0985d MB |
303 | my $pos = index $txt, "\t\t$arg\n"; |
304 | if ($[ <= $pos) { | |
305 | my $posLF = rindex $txt, "\n", $pos; | |
306 | (my $code = substr $txt, $posLF + 1, 6) =~ tr/\t//d; | |
307 | return $vianame{$arg} = hex $code; | |
308 | ||
309 | # If $pos is at the 1st line, $posLF must be $[ - 1 (not found); | |
310 | # then $posLF + 1 equals to $[ (at the beginning of $txt). | |
311 | # Otherwise $posLF is the position of "\n"; | |
312 | # then $posLF + 1 must be the position of the next to "\n" | |
313 | # (the beginning of the line). | |
314 | # substr($txt, $posLF + 1, 6) may be "0000\t\t", "00A1\t\t", | |
315 | # "10300\t", "100000", etc. So we can get the code via removing TAB. | |
316 | } else { | |
317 | return; | |
318 | } | |
319 | } # vianame | |
b177ca84 | 320 | |
423cee85 JH |
321 | |
322 | 1; | |
323 | __END__ | |
324 | ||
325 | =head1 NAME | |
326 | ||
274085e3 | 327 | charnames - define character names for C<\N{named}> string literal escapes |
423cee85 JH |
328 | |
329 | =head1 SYNOPSIS | |
330 | ||
331 | use charnames ':full'; | |
4a2d328f | 332 | print "\N{GREEK SMALL LETTER SIGMA} is called sigma.\n"; |
423cee85 JH |
333 | |
334 | use charnames ':short'; | |
4a2d328f | 335 | print "\N{greek:Sigma} is an upper-case sigma.\n"; |
423cee85 JH |
336 | |
337 | use charnames qw(cyrillic greek); | |
4a2d328f | 338 | print "\N{sigma} is Greek sigma, and \N{be} is Cyrillic b.\n"; |
423cee85 | 339 | |
35c0985d MB |
340 | use charnames ":full", ":alias" => { |
341 | e_ACUTE => "LATIN SMALL LETTER E WITH ACUTE", | |
76ae0c45 | 342 | }; |
35c0985d MB |
343 | print "\N{e_ACUTE} is a small letter e with an acute.\n"; |
344 | ||
76ae0c45 | 345 | use charnames (); |
a23c04e4 JH |
346 | print charnames::viacode(0x1234); # prints "ETHIOPIC SYLLABLE SEE" |
347 | printf "%04X", charnames::vianame("GOTHIC LETTER AHSA"); # prints "10330" | |
b177ca84 | 348 | |
423cee85 JH |
349 | =head1 DESCRIPTION |
350 | ||
35c0985d MB |
351 | Pragma C<use charnames> supports arguments C<:full>, C<:short>, script |
352 | names and customized aliases. If C<:full> is present, for expansion of | |
76ae0c45 RGS |
353 | C<\N{CHARNAME}>, the string C<CHARNAME> is first looked up in the list of |
354 | standard Unicode character names. If C<:short> is present, and | |
423cee85 JH |
355 | C<CHARNAME> has the form C<SCRIPT:CNAME>, then C<CNAME> is looked up |
356 | as a letter in script C<SCRIPT>. If pragma C<use charnames> is used | |
a191c821 | 357 | with script name arguments, then for C<\N{CHARNAME}> the name |
423cee85 | 358 | C<CHARNAME> is looked up as a letter in the given scripts (in the |
35c0985d | 359 | specified order). Customized aliases are explained in L</CUSTOM ALIASES>. |
423cee85 JH |
360 | |
361 | For lookup of C<CHARNAME> inside a given script C<SCRIPTNAME> | |
d5448623 | 362 | this pragma looks for the names |
423cee85 JH |
363 | |
364 | SCRIPTNAME CAPITAL LETTER CHARNAME | |
365 | SCRIPTNAME SMALL LETTER CHARNAME | |
366 | SCRIPTNAME LETTER CHARNAME | |
367 | ||
368 | in the table of standard Unicode names. If C<CHARNAME> is lowercase, | |
daf0d493 JH |
369 | then the C<CAPITAL> variant is ignored, otherwise the C<SMALL> variant |
370 | is ignored. | |
371 | ||
372 | Note that C<\N{...}> is compile-time, it's a special form of string | |
373 | constant used inside double-quoted strings: in other words, you cannot | |
4e2cda5d | 374 | use variables inside the C<\N{...}>. If you want similar run-time |
daf0d493 | 375 | functionality, use charnames::vianame(). |
423cee85 | 376 | |
301a3cda | 377 | For the C0 and C1 control characters (U+0000..U+001F, U+0080..U+009F) |
dbc0d4f2 JH |
378 | as of Unicode 3.1, there are no official Unicode names but you can use |
379 | instead the ISO 6429 names (LINE FEED, ESCAPE, and so forth). In | |
380 | Unicode 3.2 (as of Perl 5.8) some naming changes take place ISO 6429 | |
381 | has been updated, see L</ALIASES>. Also note that the U+UU80, U+0081, | |
382 | U+0084, and U+0099 do not have names even in ISO 6429. | |
383 | ||
384 | Since the Unicode standard uses "U+HHHH", so can you: "\N{U+263a}" | |
385 | is the Unicode smiley face, or "\N{WHITE SMILING FACE}". | |
301a3cda | 386 | |
423cee85 JH |
387 | =head1 CUSTOM TRANSLATORS |
388 | ||
d5448623 | 389 | The mechanism of translation of C<\N{...}> escapes is general and not |
423cee85 | 390 | hardwired into F<charnames.pm>. A module can install custom |
d5448623 | 391 | translations (inside the scope which C<use>s the module) with the |
423cee85 JH |
392 | following magic incantation: |
393 | ||
d5448623 GS |
394 | sub import { |
395 | shift; | |
d5448623 GS |
396 | $^H{charnames} = \&translator; |
397 | } | |
423cee85 JH |
398 | |
399 | Here translator() is a subroutine which takes C<CHARNAME> as an | |
400 | argument, and returns text to insert into the string instead of the | |
4a2d328f | 401 | C<\N{CHARNAME}> escape. Since the text to insert should be different |
d5448623 GS |
402 | in C<bytes> mode and out of it, the function should check the current |
403 | state of C<bytes>-flag as in: | |
404 | ||
405 | use bytes (); # for $bytes::hint_bits | |
406 | sub translator { | |
407 | if ($^H & $bytes::hint_bits) { | |
408 | return bytes_translator(@_); | |
409 | } | |
410 | else { | |
411 | return utf8_translator(@_); | |
412 | } | |
423cee85 | 413 | } |
423cee85 | 414 | |
35c0985d MB |
415 | =head1 CUSTOM ALIASES |
416 | ||
417 | This version of charnames supports three mechanisms of adding local | |
418 | or customized aliases to standard Unicode naming conventions (:full) | |
419 | ||
420 | =head2 Anonymous hashes | |
421 | ||
422 | use charnames ":full", ":alias" => { | |
423 | e_ACUTE => "LATIN SMALL LETTER E WITH ACUTE", | |
424 | }; | |
425 | my $str = "\N{e_ACUTE}"; | |
426 | ||
427 | =head2 Alias file | |
428 | ||
429 | use charnames ":full", ":alias" => "pro"; | |
430 | ||
431 | will try to read "unicore/pro_alias.pl" from the @INC path. This | |
432 | file should return a list in plain perl: | |
433 | ||
434 | ( | |
435 | A_GRAVE => "LATIN CAPITAL LETTER A WITH GRAVE", | |
436 | A_CIRCUM => "LATIN CAPITAL LETTER A WITH CIRCUMFLEX", | |
437 | A_DIAERES => "LATIN CAPITAL LETTER A WITH DIAERESIS", | |
438 | A_TILDE => "LATIN CAPITAL LETTER A WITH TILDE", | |
439 | A_BREVE => "LATIN CAPITAL LETTER A WITH BREVE", | |
440 | A_RING => "LATIN CAPITAL LETTER A WITH RING ABOVE", | |
441 | A_MACRON => "LATIN CAPITAL LETTER A WITH MACRON", | |
442 | ); | |
443 | ||
444 | =head2 Alias shortcut | |
445 | ||
446 | use charnames ":alias" => ":pro"; | |
447 | ||
448 | works exactly the same as the alias pairs, only this time, | |
449 | ":full" is inserted automatically as first argument (if no | |
450 | other argument is given). | |
451 | ||
b177ca84 JF |
452 | =head1 charnames::viacode(code) |
453 | ||
454 | Returns the full name of the character indicated by the numeric code. | |
455 | The example | |
456 | ||
457 | print charnames::viacode(0x2722); | |
458 | ||
459 | prints "FOUR TEARDROP-SPOKED ASTERISK". | |
460 | ||
daf0d493 JH |
461 | Returns undef if no name is known for the code. |
462 | ||
35c0985d | 463 | This works only for the standard names, and does not yet apply |
daf0d493 JH |
464 | to custom translators. |
465 | ||
274085e3 PN |
466 | Notice that the name returned for of U+FEFF is "ZERO WIDTH NO-BREAK |
467 | SPACE", not "BYTE ORDER MARK". | |
468 | ||
eb6a2339 | 469 | =head1 charnames::vianame(name) |
daf0d493 JH |
470 | |
471 | Returns the code point indicated by the name. | |
472 | The example | |
473 | ||
474 | printf "%04X", charnames::vianame("FOUR TEARDROP-SPOKED ASTERISK"); | |
475 | ||
476 | prints "2722". | |
477 | ||
eb6a2339 | 478 | Returns undef if the name is unknown. |
b177ca84 | 479 | |
35c0985d | 480 | This works only for the standard names, and does not yet apply |
b177ca84 JF |
481 | to custom translators. |
482 | ||
52ea3e69 JH |
483 | =head1 ALIASES |
484 | ||
485 | A few aliases have been defined for convenience: instead of having | |
486 | to use the official names | |
487 | ||
488 | LINE FEED (LF) | |
489 | FORM FEED (FF) | |
490 | CARRIAGE RETURN (CR) | |
491 | NEXT LINE (NEL) | |
492 | ||
493 | (yes, with parentheses) one can use | |
494 | ||
495 | LINE FEED | |
496 | FORM FEED | |
497 | CARRIAGE RETURN | |
498 | NEXT LINE | |
499 | LF | |
500 | FF | |
501 | CR | |
502 | NEL | |
503 | ||
504 | One can also use | |
505 | ||
506 | BYTE ORDER MARK | |
507 | BOM | |
508 | ||
24b5d5cc JH |
509 | and |
510 | ||
511 | ZWNJ | |
512 | ZWJ | |
513 | ||
514 | for ZERO WIDTH NON-JOINER and ZERO WIDTH JOINER. | |
52ea3e69 JH |
515 | |
516 | For backward compatibility one can use the old names for | |
517 | certain C0 and C1 controls | |
518 | ||
519 | old new | |
520 | ||
521 | HORIZONTAL TABULATION CHARACTER TABULATION | |
522 | VERTICAL TABULATION LINE TABULATION | |
523 | FILE SEPARATOR INFORMATION SEPARATOR FOUR | |
524 | GROUP SEPARATOR INFORMATION SEPARATOR THREE | |
525 | RECORD SEPARATOR INFORMATION SEPARATOR TWO | |
526 | UNIT SEPARATOR INFORMATION SEPARATOR ONE | |
527 | PARTIAL LINE DOWN PARTIAL LINE FORWARD | |
528 | PARTIAL LINE UP PARTIAL LINE BACKWARD | |
529 | ||
530 | but the old names in addition to giving the character | |
531 | will also give a warning about being deprecated. | |
532 | ||
f0175764 JH |
533 | =head1 ILLEGAL CHARACTERS |
534 | ||
00d835f2 JH |
535 | If you ask by name for a character that does not exist, a warning is |
536 | given and the Unicode I<replacement character> "\x{FFFD}" is returned. | |
537 | ||
538 | If you ask by code for a character that does not exist, no warning is | |
539 | given and C<undef> is returned. (Though if you ask for a code point | |
540 | past U+10FFFF you do get a warning.) | |
f0175764 | 541 | |
423cee85 JH |
542 | =head1 BUGS |
543 | ||
544 | Since evaluation of the translation function happens in a middle of | |
545 | compilation (of a string literal), the translation function should not | |
546 | do any C<eval>s or C<require>s. This restriction should be lifted in | |
547 | a future version of Perl. | |
548 | ||
549 | =cut |