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/se3-unattended/var/se3/unattended/install/linuxaux/opt/perl/lib/5.10.0/ -> charnames.pm (source)

   1  package charnames;
   2  use strict;
   3  use warnings;
   4  use File::Spec;
   5  our $VERSION = '1.06';
   6  
   7  use bytes ();        # for $bytes::hint_bits
   8  
   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)',
  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  
  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  
  40  my %alias3 = (
  41          # User defined aliasses. Even more convenient :)
  42          );
  43  my $txt;
  44  
  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  
  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  {
  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
  86  sub 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  
 187  sub 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  
 248  my %viacode;
 249  
 250  sub 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  
 286  my %vianame;
 287  
 288  sub 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  
 322  1;
 323  __END__
 324  
 325  =head1 NAME
 326  
 327  charnames - 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  
 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
 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
 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
 357  with script name arguments, then for C<\N{CHARNAME}> the name
 358  C<CHARNAME> is looked up as a letter in the given scripts (in the
 359  specified order). Customized aliases are explained in L</CUSTOM ALIASES>.
 360  
 361  For lookup of C<CHARNAME> inside a given script C<SCRIPTNAME>
 362  this pragma looks for the names
 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,
 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
 374  use variables inside the C<\N{...}>.  If you want similar run-time
 375  functionality, use charnames::vianame().
 376  
 377  For the C0 and C1 control characters (U+0000..U+001F, U+0080..U+009F)
 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}".
 386  
 387  =head1 ALIASES
 388  
 389  A few aliases have been defined for convenience: instead of having
 390  to 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  
 408  One can also use
 409  
 410      BYTE ORDER MARK
 411      BOM
 412  
 413  and
 414  
 415      ZWNJ
 416      ZWJ
 417  
 418  for ZERO WIDTH NON-JOINER and ZERO WIDTH JOINER.
 419  
 420  For backward compatibility one can use the old names for
 421  certain 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  
 434  but the old names in addition to giving the character
 435  will also give a warning about being deprecated.
 436  
 437  =head1 CUSTOM ALIASES
 438  
 439  This version of charnames supports three mechanisms of adding local
 440  or 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  
 476  Returns the full name of the character indicated by the numeric code.
 477  The example
 478  
 479      print charnames::viacode(0x2722);
 480  
 481  prints "FOUR TEARDROP-SPOKED ASTERISK".
 482  
 483  Returns undef if no name is known for the code.
 484  
 485  This works only for the standard names, and does not yet apply
 486  to custom translators.
 487  
 488  Notice that the name returned for of U+FEFF is "ZERO WIDTH NO-BREAK
 489  SPACE", not "BYTE ORDER MARK".
 490  
 491  =head1 charnames::vianame(name)
 492  
 493  Returns the code point indicated by the name.
 494  The example
 495  
 496      printf "%04X", charnames::vianame("FOUR TEARDROP-SPOKED ASTERISK");
 497  
 498  prints "2722".
 499  
 500  Returns undef if the name is unknown.
 501  
 502  This works only for the standard names, and does not yet apply
 503  to custom translators.
 504  
 505  =head1 CUSTOM TRANSLATORS
 506  
 507  The mechanism of translation of C<\N{...}> escapes is general and not
 508  hardwired into F<charnames.pm>.  A module can install custom
 509  translations (inside the scope which C<use>s the module) with the
 510  following magic incantation:
 511  
 512      sub import {
 513      shift;
 514      $^H{charnames} = \&translator;
 515      }
 516  
 517  Here translator() is a subroutine which takes C<CHARNAME> as an
 518  argument, and returns text to insert into the string instead of the
 519  C<\N{CHARNAME}> escape.  Since the text to insert should be different
 520  in C<bytes> mode and out of it, the function should check the current
 521  state 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  
 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.)
 541  
 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


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