1package charnames; 2use strict; 3use warnings; 4use Carp; 5our $VERSION = '1.01'; 6 7use bytes (); # for $bytes::hint_bits 8$charnames::hint_bits = 0x20000; 9 10my %alias1 = ( 11 # Icky 3.2 names with parentheses. 12 'LINE FEED' => 'LINE FEED (LF)', 13 'FORM FEED' => 'FORM FEED (FF)', 14 'CARRIAGE RETURN' => 'CARRIAGE RETURN (CR)', 15 'NEXT LINE' => 'NEXT LINE (NEL)', 16 # Convenience. 17 'LF' => 'LINE FEED (LF)', 18 'FF' => 'FORM FEED (FF)', 19 'CR' => 'CARRIAGE RETURN (CR)', 20 'NEL' => 'NEXT LINE (NEL)', 21 # More convenience. For futher convencience, 22 # it is suggested some way using using the NamesList 23 # aliases is implemented. 24 'ZWNJ' => 'ZERO WIDTH NON-JOINER', 25 'ZWJ' => 'ZERO WIDTH JOINER', 26 'BOM' => 'BYTE ORDER MARK', 27 ); 28 29my %alias2 = ( 30 # Pre-3.2 compatibility (only for the first 256 characters). 31 'HORIZONTAL TABULATION' => 'CHARACTER TABULATION', 32 'VERTICAL TABULATION' => 'LINE TABULATION', 33 'FILE SEPARATOR' => 'INFORMATION SEPARATOR FOUR', 34 'GROUP SEPARATOR' => 'INFORMATION SEPARATOR THREE', 35 'RECORD SEPARATOR' => 'INFORMATION SEPARATOR TWO', 36 'UNIT SEPARATOR' => 'INFORMATION SEPARATOR ONE', 37 'PARTIAL LINE DOWN' => 'PARTIAL LINE FORWARD', 38 'PARTIAL LINE UP' => 'PARTIAL LINE BACKWARD', 39 ); 40 41my $txt; 42 43# This is not optimized in any way yet 44sub charnames 45{ 46 my $name = shift; 47 48 if (exists $alias1{$name}) { 49 $name = $alias1{$name}; 50 } 51 if (exists $alias2{$name}) { 52 require warnings; 53 warnings::warnif('deprecated', qq{Unicode character name "$name" is deprecated, use "$alias2{$name}" instead}); 54 $name = $alias2{$name}; 55 } 56 57 my $ord; 58 my @off; 59 my $fname; 60 61 if ($name eq "BYTE ORDER MARK") { 62 $fname = $name; 63 $ord = 0xFEFF; 64 } else { 65 ## Suck in the code/name list as a big string. 66 ## Lines look like: 67 ## "0052\t\tLATIN CAPITAL LETTER R\n" 68 $txt = do "unicore/Name.pl" unless $txt; 69 70 ## @off will hold the index into the code/name string of the start and 71 ## end of the name as we find it. 72 73 ## If :full, look for the the name exactly 74 if ($^H{charnames_full} and $txt =~ /\t\t\Q$name\E$/m) { 75 @off = ($-[0], $+[0]); 76 } 77 78 ## If we didn't get above, and :short allowed, look for the short name. 79 ## The short name is like "greek:Sigma" 80 unless (@off) { 81 if ($^H{charnames_short} and $name =~ /^(.+?):(.+)/s) { 82 my ($script, $cname) = ($1,$2); 83 my $case = ( $cname =~ /[[:upper:]]/ ? "CAPITAL" : "SMALL"); 84 if ($txt =~ m/\t\t\U$script\E (?:$case )?LETTER \U\Q$cname\E$/m) { 85 @off = ($-[0], $+[0]); 86 } 87 } 88 } 89 90 ## If we still don't have it, check for the name among the loaded 91 ## scripts. 92 if (not @off) 93 { 94 my $case = ( $name =~ /[[:upper:]]/ ? "CAPITAL" : "SMALL"); 95 for my $script ( @{$^H{charnames_scripts}} ) 96 { 97 if ($txt =~ m/\t\t$script (?:$case )?LETTER \U\Q$name\E$/m) { 98 @off = ($-[0], $+[0]); 99 last; 100 } 101 } 102 } 103 104 ## If we don't have it by now, give up. 105 unless (@off) { 106 carp "Unknown charname '$name'"; 107 return "\x{FFFD}"; 108 } 109 110 ## 111 ## Now know where in the string the name starts. 112 ## The code, in hex, is before that. 113 ## 114 ## The code can be 4-6 characters long, so we've got to sort of 115 ## go look for it, just after the newline that comes before $off[0]. 116 ## 117 ## This would be much easier if unicore/Name.pl had info in 118 ## a name/code order, instead of code/name order. 119 ## 120 ## The +1 after the rindex() is to skip past the newline we're finding, 121 ## or, if the rindex() fails, to put us to an offset of zero. 122 ## 123 my $hexstart = rindex($txt, "\n", $off[0]) + 1; 124 125 ## we know where it starts, so turn into number - 126 ## the ordinal for the char. 127 $ord = hex substr($txt, $hexstart, $off[0] - $hexstart); 128 } 129 130 if ($^H & $bytes::hint_bits) { # "use bytes" in effect? 131 use bytes; 132 return chr $ord if $ord <= 255; 133 my $hex = sprintf "%04x", $ord; 134 if (not defined $fname) { 135 $fname = substr $txt, $off[0] + 2, $off[1] - $off[0] - 2; 136 } 137 croak "Character 0x$hex with name '$fname' is above 0xFF"; 138 } 139 140 no warnings 'utf8'; # allow even illegal characters 141 return pack "U", $ord; 142} 143 144sub import 145{ 146 shift; ## ignore class name 147 148 if (not @_) 149 { 150 carp("`use charnames' needs explicit imports list"); 151 } 152 $^H |= $charnames::hint_bits; 153 $^H{charnames} = \&charnames ; 154 155 ## 156 ## fill %h keys with our @_ args. 157 ## 158 my %h; 159 @h{@_} = (1) x @_; 160 161 $^H{charnames_full} = delete $h{':full'}; 162 $^H{charnames_short} = delete $h{':short'}; 163 $^H{charnames_scripts} = [map uc, keys %h]; 164 165 ## 166 ## If utf8? warnings are enabled, and some scripts were given, 167 ## see if at least we can find one letter of each script. 168 ## 169 if (warnings::enabled('utf8') && @{$^H{charnames_scripts}}) 170 { 171 $txt = do "unicore/Name.pl" unless $txt; 172 173 for my $script (@{$^H{charnames_scripts}}) 174 { 175 if (not $txt =~ m/\t\t$script (?:CAPITAL |SMALL )?LETTER /) { 176 warnings::warn('utf8', "No such script: '$script'"); 177 } 178 } 179 } 180} 181 182require Unicode::UCD; # for Unicode::UCD::_getcode() 183 184my %viacode; 185 186sub viacode 187{ 188 if (@_ != 1) { 189 carp "charnames::viacode() expects one argument"; 190 return () 191 } 192 193 my $arg = shift; 194 my $code = Unicode::UCD::_getcode($arg); 195 196 my $hex; 197 198 if (defined $code) { 199 $hex = sprintf "%04X", $arg; 200 } else { 201 carp("unexpected arg \"$arg\" to charnames::viacode()"); 202 return; 203 } 204 205 if ($code > 0x10FFFF) { 206 carp sprintf "Unicode characters only allocated up to U+10FFFF (you asked for U+%X)", $hex; 207 return; 208 } 209 210 return $viacode{$hex} if exists $viacode{$hex}; 211 212 $txt = do "unicore/Name.pl" unless $txt; 213 214 if ($txt =~ m/^$hex\t\t(.+)/m) { 215 return $viacode{$hex} = $1; 216 } else { 217 return; 218 } 219} 220 221my %vianame; 222 223sub vianame 224{ 225 if (@_ != 1) { 226 carp "charnames::vianame() expects one name argument"; 227 return () 228 } 229 230 my $arg = shift; 231 232 return chr hex $1 if $arg =~ /^U\+([0-9a-fA-F]+)$/; 233 234 return $vianame{$arg} if exists $vianame{$arg}; 235 236 $txt = do "unicore/Name.pl" unless $txt; 237 238 my $pos = index $txt, "\t\t$arg\n"; 239 if ($[ <= $pos) { 240 my $posLF = rindex $txt, "\n", $pos; 241 (my $code = substr $txt, $posLF + 1, 6) =~ tr/\t//d; 242 return $vianame{$arg} = hex $code; 243 244 # If $pos is at the 1st line, $posLF must be $[ - 1 (not found); 245 # then $posLF + 1 equals to $[ (at the beginning of $txt). 246 # Otherwise $posLF is the position of "\n"; 247 # then $posLF + 1 must be the position of the next to "\n" 248 # (the beginning of the line). 249 # substr($txt, $posLF + 1, 6) may be "0000\t\t", "00A1\t\t", 250 # "10300\t", "100000", etc. So we can get the code via removing TAB. 251 } else { 252 return; 253 } 254} 255 256 2571; 258__END__ 259 260=head1 NAME 261 262charnames - define character names for C<\N{named}> string literal escapes 263 264=head1 SYNOPSIS 265 266 use charnames ':full'; 267 print "\N{GREEK SMALL LETTER SIGMA} is called sigma.\n"; 268 269 use charnames ':short'; 270 print "\N{greek:Sigma} is an upper-case sigma.\n"; 271 272 use charnames qw(cyrillic greek); 273 print "\N{sigma} is Greek sigma, and \N{be} is Cyrillic b.\n"; 274 275 print charnames::viacode(0x1234); # prints "ETHIOPIC SYLLABLE SEE" 276 printf "%04X", charnames::vianame("GOTHIC LETTER AHSA"); # prints "10330" 277 278=head1 DESCRIPTION 279 280Pragma C<use charnames> supports arguments C<:full>, C<:short> and 281script names. If C<:full> is present, for expansion of 282C<\N{CHARNAME}> string C<CHARNAME> is first looked in the list of 283standard Unicode names of chars. If C<:short> is present, and 284C<CHARNAME> has the form C<SCRIPT:CNAME>, then C<CNAME> is looked up 285as a letter in script C<SCRIPT>. If pragma C<use charnames> is used 286with script name arguments, then for C<\N{CHARNAME}> the name 287C<CHARNAME> is looked up as a letter in the given scripts (in the 288specified order). 289 290For lookup of C<CHARNAME> inside a given script C<SCRIPTNAME> 291this pragma looks for the names 292 293 SCRIPTNAME CAPITAL LETTER CHARNAME 294 SCRIPTNAME SMALL LETTER CHARNAME 295 SCRIPTNAME LETTER CHARNAME 296 297in the table of standard Unicode names. If C<CHARNAME> is lowercase, 298then the C<CAPITAL> variant is ignored, otherwise the C<SMALL> variant 299is ignored. 300 301Note that C<\N{...}> is compile-time, it's a special form of string 302constant used inside double-quoted strings: in other words, you cannot 303use variables inside the C<\N{...}>. If you want similar run-time 304functionality, use charnames::vianame(). 305 306For the C0 and C1 control characters (U+0000..U+001F, U+0080..U+009F) 307as of Unicode 3.1, there are no official Unicode names but you can use 308instead the ISO 6429 names (LINE FEED, ESCAPE, and so forth). In 309Unicode 3.2 (as of Perl 5.8) some naming changes take place ISO 6429 310has been updated, see L</ALIASES>. Also note that the U+UU80, U+0081, 311U+0084, and U+0099 do not have names even in ISO 6429. 312 313Since the Unicode standard uses "U+HHHH", so can you: "\N{U+263a}" 314is the Unicode smiley face, or "\N{WHITE SMILING FACE}". 315 316=head1 CUSTOM TRANSLATORS 317 318The mechanism of translation of C<\N{...}> escapes is general and not 319hardwired into F<charnames.pm>. A module can install custom 320translations (inside the scope which C<use>s the module) with the 321following magic incantation: 322 323 use charnames (); # for $charnames::hint_bits 324 sub import { 325 shift; 326 $^H |= $charnames::hint_bits; 327 $^H{charnames} = \&translator; 328 } 329 330Here translator() is a subroutine which takes C<CHARNAME> as an 331argument, and returns text to insert into the string instead of the 332C<\N{CHARNAME}> escape. Since the text to insert should be different 333in C<bytes> mode and out of it, the function should check the current 334state of C<bytes>-flag as in: 335 336 use bytes (); # for $bytes::hint_bits 337 sub translator { 338 if ($^H & $bytes::hint_bits) { 339 return bytes_translator(@_); 340 } 341 else { 342 return utf8_translator(@_); 343 } 344 } 345 346=head1 charnames::viacode(code) 347 348Returns the full name of the character indicated by the numeric code. 349The example 350 351 print charnames::viacode(0x2722); 352 353prints "FOUR TEARDROP-SPOKED ASTERISK". 354 355Returns undef if no name is known for the code. 356 357This works only for the standard names, and does not yet apply 358to custom translators. 359 360Notice that the name returned for of U+FEFF is "ZERO WIDTH NO-BREAK 361SPACE", not "BYTE ORDER MARK". 362 363=head1 charnames::vianame(name) 364 365Returns the code point indicated by the name. 366The example 367 368 printf "%04X", charnames::vianame("FOUR TEARDROP-SPOKED ASTERISK"); 369 370prints "2722". 371 372Returns undef if the name is unknown. 373 374This works only for the standard names, and does not yet apply 375to custom translators. 376 377=head1 ALIASES 378 379A few aliases have been defined for convenience: instead of having 380to use the official names 381 382 LINE FEED (LF) 383 FORM FEED (FF) 384 CARRIAGE RETURN (CR) 385 NEXT LINE (NEL) 386 387(yes, with parentheses) one can use 388 389 LINE FEED 390 FORM FEED 391 CARRIAGE RETURN 392 NEXT LINE 393 LF 394 FF 395 CR 396 NEL 397 398One can also use 399 400 BYTE ORDER MARK 401 BOM 402 403and 404 405 ZWNJ 406 ZWJ 407 408for ZERO WIDTH NON-JOINER and ZERO WIDTH JOINER. 409 410For backward compatibility one can use the old names for 411certain C0 and C1 controls 412 413 old new 414 415 HORIZONTAL TABULATION CHARACTER TABULATION 416 VERTICAL TABULATION LINE TABULATION 417 FILE SEPARATOR INFORMATION SEPARATOR FOUR 418 GROUP SEPARATOR INFORMATION SEPARATOR THREE 419 RECORD SEPARATOR INFORMATION SEPARATOR TWO 420 UNIT SEPARATOR INFORMATION SEPARATOR ONE 421 PARTIAL LINE DOWN PARTIAL LINE FORWARD 422 PARTIAL LINE UP PARTIAL LINE BACKWARD 423 424but the old names in addition to giving the character 425will also give a warning about being deprecated. 426 427=head1 ILLEGAL CHARACTERS 428 429If you ask by name for a character that does not exist, a warning is 430given and the Unicode I<replacement character> "\x{FFFD}" is returned. 431 432If you ask by code for a character that does not exist, no warning is 433given and C<undef> is returned. (Though if you ask for a code point 434past U+10FFFF you do get a warning.) 435 436=head1 BUGS 437 438Since evaluation of the translation function happens in a middle of 439compilation (of a string literal), the translation function should not 440do any C<eval>s or C<require>s. This restriction should be lifted in 441a future version of Perl. 442 443=cut 444