1package charnames; 2use strict; 3use warnings; 4use File::Spec; 5our $VERSION = '1.06'; 6 7use bytes (); # for $bytes::hint_bits 8 9my %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)', 18 'CR' => 'CARRIAGE RETURN (CR)', 19 'NEL' => 'NEXT LINE (NEL)', 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', 25 'BOM' => 'BYTE ORDER MARK', 26 ); 27 28my %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 40my %alias3 = ( 41 # User defined aliasses. Even more convenient :) 42 ); 43my $txt; 44 45sub croak 46{ 47 require Carp; goto &Carp::croak; 48} # croak 49 50sub carp 51{ 52 require Carp; goto &Carp::carp; 53} # carp 54 55sub alias (@) 56{ 57 @_ or return %alias3; 58 my $alias = ref $_[0] ? $_[0] : { @_ }; 59 @alias3{keys %$alias} = values %$alias; 60} # alias 61 62sub alias_file ($) 63{ 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 } 74 if (my @alias = do $file) { 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"; 79 alias (@alias); 80 return (1); 81 } 82 0; 83} # alias_file 84 85# This is not optimized in any way yet 86sub charnames 87{ 88 my $name = shift; 89 90 if (exists $alias1{$name}) { 91 $name = $alias1{$name}; 92 } 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}; 100 } 101 102 my $ord; 103 my @off; 104 my $fname; 105 106 if ($name eq "BYTE ORDER MARK") { 107 $fname = $name; 108 $ord = 0xFEFF; 109 } else { 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 $txt; 114 115 ## @off will hold the index into the code/name string of the start and 116 ## end of the name as we find it. 117 118 ## If :full, look for the name exactly 119 if ($^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) { 130 @off = ($-[0], $+[0]); 131 } 132 } 133 } 134 135 ## 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], $+[0]); 142 last; 143 } 144 } 145 } 146 147 ## If we don't have it by now, give up. 148 unless (@off) { 149 carp "Unknown charname '$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 $ord = CORE::hex substr($txt, $hexstart, $off[0] - $hexstart); 171 } 172 173 if ($^H & $bytes::hint_bits) { # "use bytes" in effect? 174 use bytes; 175 return chr $ord if $ord <= 255; 176 my $hex = sprintf "%04x", $ord; 177 if (not defined $fname) { 178 $fname = substr $txt, $off[0] + 2, $off[1] - $off[0] - 2; 179 } 180 croak "Character 0x$hex with name '$fname' is above 0xFF"; 181 } 182 183 no warnings 'utf8'; # allow even illegal characters 184 return pack "U", $ord; 185} # charnames 186 187sub import 188{ 189 shift; ## ignore class name 190 191 if (not @_) { 192 carp("`use charnames' needs explicit imports list"); 193 } 194 $^H{charnames} = \&charnames ; 195 196 ## 197 ## fill %h keys with our @_ args. 198 ## 199 my ($promote, %h, @args) = (0); 200 while (my $arg = shift) { 201 if ($arg eq ":alias") { 202 @_ or 203 croak ":alias needs an argument in charnames"; 204 my $alias = shift; 205 if (ref $alias) { 206 ref $alias eq "HASH" or 207 croak "Only HASH reference supported as argument to :alias"; 208 alias ($alias); 209 next; 210 } 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 $promote = 1; 215 next; 216 } 217 alias_file ($alias); 218 next; 219 } 220 if (substr($arg, 0, 1) eq ':' and ! ($arg eq ":full" || $arg eq ":short")) { 221 warn "unsupported special '$arg' in charnames"; 222 next; 223 } 224 push @args, $arg; 225 } 226 @args == 0 && $promote and @args = (":full"); 227 @h{@args} = (1) x @args; 228 229 $^H{charnames_full} = delete $h{':full'}; 230 $^H{charnames_short} = delete $h{':short'}; 231 $^H{charnames_scripts} = [map uc, keys %h]; 232 233 ## 234 ## If utf8? warnings are enabled, and some scripts were given, 235 ## see if at least we can find one letter of each script. 236 ## 237 if (warnings::enabled('utf8') && @{$^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'"); 243 } 244 } 245 } 246} # import 247 248my %viacode; 249 250sub viacode 251{ 252 if (@_ != 1) { 253 carp "charnames::viacode() expects one argument"; 254 return; 255 } 256 257 my $arg = shift; 258 259 # this comes actually from Unicode::UCD, where it is the named 260 # function _getcode (), but it avoids the overhead of loading it 261 my $hex; 262 if ($arg =~ /^[1-9]\d*$/) { 263 $hex = sprintf "%04X", $arg; 264 } elsif ($arg =~ /^(?:[Uu]\+|0[xX])?([[:xdigit:]]+)$/) { 265 $hex = $1; 266 } else { 267 carp("unexpected arg \"$arg\" to charnames::viacode()"); 268 return; 269 } 270 271 # checking the length first is slightly faster 272 if (length($hex) > 5 && hex($hex) > 0x10FFFF) { 273 carp "Unicode characters only allocated up to U+10FFFF (you asked for U+$hex)"; 274 return; 275 } 276 277 return $viacode{$hex} if exists $viacode{$hex}; 278 279 $txt = do "unicore/Name.pl" unless $txt; 280 281 return unless $txt =~ m/^$hex\t\t(.+)/m; 282 283 $viacode{$hex} = $1; 284} # viacode 285 286my %vianame; 287 288sub vianame 289{ 290 if (@_ != 1) { 291 carp "charnames::vianame() expects one name argument"; 292 return () 293 } 294 295 my $arg = shift; 296 297 return chr CORE::hex $1 if $arg =~ /^U\+([0-9a-fA-F]+)$/; 298 299 return $vianame{$arg} if exists $vianame{$arg}; 300 301 $txt = do "unicore/Name.pl" unless $txt; 302 303 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} = CORE::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 320 321 3221; 323__END__ 324 325=head1 NAME 326 327charnames - define character names for C<\N{named}> string literal escapes 328 329=head1 SYNOPSIS 330 331 use charnames ':full'; 332 print "\N{GREEK SMALL LETTER SIGMA} is called sigma.\n"; 333 334 use charnames ':short'; 335 print "\N{greek:Sigma} is an upper-case sigma.\n"; 336 337 use charnames qw(cyrillic greek); 338 print "\N{sigma} is Greek sigma, and \N{be} is Cyrillic b.\n"; 339 340 use charnames ":full", ":alias" => { 341 e_ACUTE => "LATIN SMALL LETTER E WITH ACUTE", 342 }; 343 print "\N{e_ACUTE} is a small letter e with an acute.\n"; 344 345 use charnames (); 346 print charnames::viacode(0x1234); # prints "ETHIOPIC SYLLABLE SEE" 347 printf "%04X", charnames::vianame("GOTHIC LETTER AHSA"); # prints "10330" 348 349=head1 DESCRIPTION 350 351Pragma C<use charnames> supports arguments C<:full>, C<:short>, script 352names and customized aliases. If C<:full> is present, for expansion of 353C<\N{CHARNAME}>, the string C<CHARNAME> is first looked up in the list of 354standard Unicode character names. If C<:short> is present, and 355C<CHARNAME> has the form C<SCRIPT:CNAME>, then C<CNAME> is looked up 356as a letter in script C<SCRIPT>. If pragma C<use charnames> is used 357with script name arguments, then for C<\N{CHARNAME}> the name 358C<CHARNAME> is looked up as a letter in the given scripts (in the 359specified order). Customized aliases are explained in L</CUSTOM ALIASES>. 360 361For lookup of C<CHARNAME> inside a given script C<SCRIPTNAME> 362this pragma looks for the names 363 364 SCRIPTNAME CAPITAL LETTER CHARNAME 365 SCRIPTNAME SMALL LETTER CHARNAME 366 SCRIPTNAME LETTER CHARNAME 367 368in the table of standard Unicode names. If C<CHARNAME> is lowercase, 369then the C<CAPITAL> variant is ignored, otherwise the C<SMALL> variant 370is ignored. 371 372Note that C<\N{...}> is compile-time, it's a special form of string 373constant used inside double-quoted strings: in other words, you cannot 374use variables inside the C<\N{...}>. If you want similar run-time 375functionality, use charnames::vianame(). 376 377For the C0 and C1 control characters (U+0000..U+001F, U+0080..U+009F) 378as of Unicode 3.1, there are no official Unicode names but you can use 379instead the ISO 6429 names (LINE FEED, ESCAPE, and so forth). In 380Unicode 3.2 (as of Perl 5.8) some naming changes take place ISO 6429 381has been updated, see L</ALIASES>. Also note that the U+UU80, U+0081, 382U+0084, and U+0099 do not have names even in ISO 6429. 383 384Since the Unicode standard uses "U+HHHH", so can you: "\N{U+263a}" 385is the Unicode smiley face, or "\N{WHITE SMILING FACE}". 386 387=head1 ALIASES 388 389A few aliases have been defined for convenience: instead of having 390to use the official names 391 392 LINE FEED (LF) 393 FORM FEED (FF) 394 CARRIAGE RETURN (CR) 395 NEXT LINE (NEL) 396 397(yes, with parentheses) one can use 398 399 LINE FEED 400 FORM FEED 401 CARRIAGE RETURN 402 NEXT LINE 403 LF 404 FF 405 CR 406 NEL 407 408One can also use 409 410 BYTE ORDER MARK 411 BOM 412 413and 414 415 ZWNJ 416 ZWJ 417 418for ZERO WIDTH NON-JOINER and ZERO WIDTH JOINER. 419 420For backward compatibility one can use the old names for 421certain C0 and C1 controls 422 423 old new 424 425 HORIZONTAL TABULATION CHARACTER TABULATION 426 VERTICAL TABULATION LINE TABULATION 427 FILE SEPARATOR INFORMATION SEPARATOR FOUR 428 GROUP SEPARATOR INFORMATION SEPARATOR THREE 429 RECORD SEPARATOR INFORMATION SEPARATOR TWO 430 UNIT SEPARATOR INFORMATION SEPARATOR ONE 431 PARTIAL LINE DOWN PARTIAL LINE FORWARD 432 PARTIAL LINE UP PARTIAL LINE BACKWARD 433 434but the old names in addition to giving the character 435will also give a warning about being deprecated. 436 437=head1 CUSTOM ALIASES 438 439This version of charnames supports three mechanisms of adding local 440or customized aliases to standard Unicode naming conventions (:full) 441 442=head2 Anonymous hashes 443 444 use charnames ":full", ":alias" => { 445 e_ACUTE => "LATIN SMALL LETTER E WITH ACUTE", 446 }; 447 my $str = "\N{e_ACUTE}"; 448 449=head2 Alias file 450 451 use charnames ":full", ":alias" => "pro"; 452 453 will try to read "unicore/pro_alias.pl" from the @INC path. This 454 file should return a list in plain perl: 455 456 ( 457 A_GRAVE => "LATIN CAPITAL LETTER A WITH GRAVE", 458 A_CIRCUM => "LATIN CAPITAL LETTER A WITH CIRCUMFLEX", 459 A_DIAERES => "LATIN CAPITAL LETTER A WITH DIAERESIS", 460 A_TILDE => "LATIN CAPITAL LETTER A WITH TILDE", 461 A_BREVE => "LATIN CAPITAL LETTER A WITH BREVE", 462 A_RING => "LATIN CAPITAL LETTER A WITH RING ABOVE", 463 A_MACRON => "LATIN CAPITAL LETTER A WITH MACRON", 464 ); 465 466=head2 Alias shortcut 467 468 use charnames ":alias" => ":pro"; 469 470 works exactly the same as the alias pairs, only this time, 471 ":full" is inserted automatically as first argument (if no 472 other argument is given). 473 474=head1 charnames::viacode(code) 475 476Returns the full name of the character indicated by the numeric code. 477The example 478 479 print charnames::viacode(0x2722); 480 481prints "FOUR TEARDROP-SPOKED ASTERISK". 482 483Returns undef if no name is known for the code. 484 485This works only for the standard names, and does not yet apply 486to custom translators. 487 488Notice that the name returned for of U+FEFF is "ZERO WIDTH NO-BREAK 489SPACE", not "BYTE ORDER MARK". 490 491=head1 charnames::vianame(name) 492 493Returns the code point indicated by the name. 494The example 495 496 printf "%04X", charnames::vianame("FOUR TEARDROP-SPOKED ASTERISK"); 497 498prints "2722". 499 500Returns undef if the name is unknown. 501 502This works only for the standard names, and does not yet apply 503to custom translators. 504 505=head1 CUSTOM TRANSLATORS 506 507The mechanism of translation of C<\N{...}> escapes is general and not 508hardwired into F<charnames.pm>. A module can install custom 509translations (inside the scope which C<use>s the module) with the 510following magic incantation: 511 512 sub import { 513 shift; 514 $^H{charnames} = \&translator; 515 } 516 517Here translator() is a subroutine which takes C<CHARNAME> as an 518argument, and returns text to insert into the string instead of the 519C<\N{CHARNAME}> escape. Since the text to insert should be different 520in C<bytes> mode and out of it, the function should check the current 521state of C<bytes>-flag as in: 522 523 use bytes (); # for $bytes::hint_bits 524 sub translator { 525 if ($^H & $bytes::hint_bits) { 526 return bytes_translator(@_); 527 } 528 else { 529 return utf8_translator(@_); 530 } 531 } 532 533=head1 ILLEGAL CHARACTERS 534 535If you ask by name for a character that does not exist, a warning is 536given and the Unicode I<replacement character> "\x{FFFD}" is returned. 537 538If you ask by code for a character that does not exist, no warning is 539given and C<undef> is returned. (Though if you ask for a code point 540past U+10FFFF you do get a warning.) 541 542=head1 BUGS 543 544Since evaluation of the translation function happens in a middle of 545compilation (of a string literal), the translation function should not 546do any C<eval>s or C<require>s. This restriction should be lifted in 547a future version of Perl. 548 549=cut 550