[perl5.git] / lib / charnames.pm

package charnames;
use strict;
use warnings;
use Carp;
use File::Spec;
our $VERSION = '1.02';

use bytes ();		# for $bytes::hint_bits
$charnames::hint_bits = 0x20000; # HINT_LOCALIZE_HH

my %alias1 = (
		# Icky 3.2 names with parentheses.
		'LINE FEED'		=> 'LINE FEED (LF)',
		'FORM FEED'		=> 'FORM FEED (FF)',
		'CARRIAGE RETURN'	=> 'CARRIAGE RETURN (CR)',
		'NEXT LINE'		=> 'NEXT LINE (NEL)',
		# Convenience.
		'LF'			=> 'LINE FEED (LF)',
		'FF'			=> 'FORM FEED (FF)',
		'CR'			=> 'CARRIAGE RETURN (CR)',
		'NEL'			=> 'NEXT LINE (NEL)',
	        # More convenience.  For futher convencience,
	        # it is suggested some way using using the NamesList
		# aliases is implemented.
	        'ZWNJ'			=> 'ZERO WIDTH NON-JOINER',
	        'ZWJ'			=> 'ZERO WIDTH JOINER',
		'BOM'			=> 'BYTE ORDER MARK',
	    );

my %alias2 = (
		# Pre-3.2 compatibility (only for the first 256 characters).
		'HORIZONTAL TABULATION'	=> 'CHARACTER TABULATION',
		'VERTICAL TABULATION'	=> 'LINE TABULATION',
		'FILE SEPARATOR'	=> 'INFORMATION SEPARATOR FOUR',
		'GROUP SEPARATOR'	=> 'INFORMATION SEPARATOR THREE',
		'RECORD SEPARATOR'	=> 'INFORMATION SEPARATOR TWO',
		'UNIT SEPARATOR'	=> 'INFORMATION SEPARATOR ONE',
		'PARTIAL LINE DOWN'	=> 'PARTIAL LINE FORWARD',
		'PARTIAL LINE UP'	=> 'PARTIAL LINE BACKWARD',
	    );

my %alias3 = (
		# User defined aliasses. Even more convenient :)
	    );
my $txt;

sub alias (@)
{
  @_ or return %alias3;
  my $alias = ref $_[0] ? $_[0] : { @_ };
  @alias3{keys %$alias} = values %$alias;
} # alias

sub alias_file ($)
{
  my ($arg, $file) = @_;
  if (-f $arg && File::Spec->file_name_is_absolute ($arg)) {
    $file = $arg;
  }
  elsif ($arg =~ m/^\w+$/) {
    $file = "unicore/${arg}_alias.pl";
  }
  else {
    croak "Charnames alias files can only have identifier characters";
  }
  if (my @alias = do $file) {
    @alias == 1 && !defined $alias[0] and
      croak "$file cannot be used as alias file for charnames";
    @alias % 2 and
      croak "$file did not return a (valid) list of alias pairs";
    alias (@alias);
    return (1);
  }
  0;
} # alias_file

# This is not optimized in any way yet
sub charnames
{
  my $name = shift;

  if (exists $alias1{$name}) {
    $name = $alias1{$name};
  }
  elsif (exists $alias2{$name}) {
    require warnings;
    warnings::warnif('deprecated', qq{Unicode character name "$name" is deprecated, use "$alias2{$name}" instead});
    $name = $alias2{$name};
  }
  elsif (exists $alias3{$name}) {
    $name = $alias3{$name};
  }

  my $ord;
  my @off;
  my $fname;

  if ($name eq "BYTE ORDER MARK") {
    $fname = $name;
    $ord = 0xFEFF;
  } else {
    ## Suck in the code/name list as a big string.
    ## Lines look like:
    ##     "0052\t\tLATIN CAPITAL LETTER R\n"
    $txt = do "unicore/Name.pl" unless $txt;

    ## @off will hold the index into the code/name string of the start and
    ## end of the name as we find it.

    ## If :full, look for the name exactly
    if ($^H{charnames_full} and $txt =~ /\t\t\Q$name\E$/m) {
      @off = ($-[0], $+[0]);
    }

    ## If we didn't get above, and :short allowed, look for the short name.
    ## The short name is like "greek:Sigma"
    unless (@off) {
      if ($^H{charnames_short} and $name =~ /^(.+?):(.+)/s) {
	my ($script, $cname) = ($1, $2);
	my $case = $cname =~ /[[:upper:]]/ ? "CAPITAL" : "SMALL";
	if ($txt =~ m/\t\t\U$script\E (?:$case )?LETTER \U\Q$cname\E$/m) {
	  @off = ($-[0], $+[0]);
	}
      }
    }

    ## If we still don't have it, check for the name among the loaded
    ## scripts.
    if (not @off) {
      my $case = $name =~ /[[:upper:]]/ ? "CAPITAL" : "SMALL";
      for my $script (@{$^H{charnames_scripts}}) {
	if ($txt =~ m/\t\t$script (?:$case )?LETTER \U\Q$name\E$/m) {
	  @off = ($-[0], $+[0]);
	  last;
	}
      }
    }

    ## If we don't have it by now, give up.
    unless (@off) {
      carp "Unknown charname '$name'";
      return "\x{FFFD}";
    }

    ##
    ## Now know where in the string the name starts.
    ## The code, in hex, is before that.
    ##
    ## The code can be 4-6 characters long, so we've got to sort of
    ## go look for it, just after the newline that comes before $off[0].
    ##
    ## This would be much easier if unicore/Name.pl had info in
    ## a name/code order, instead of code/name order.
    ##
    ## The +1 after the rindex() is to skip past the newline we're finding,
    ## or, if the rindex() fails, to put us to an offset of zero.
    ##
    my $hexstart = rindex($txt, "\n", $off[0]) + 1;

    ## we know where it starts, so turn into number -
    ## the ordinal for the char.
    $ord = hex substr($txt, $hexstart, $off[0] - $hexstart);
  }

  if ($^H & $bytes::hint_bits) {	# "use bytes" in effect?
    use bytes;
    return chr $ord if $ord <= 255;
    my $hex = sprintf "%04x", $ord;
    if (not defined $fname) {
      $fname = substr $txt, $off[0] + 2, $off[1] - $off[0] - 2;
    }
    croak "Character 0x$hex with name '$fname' is above 0xFF";
  }

  no warnings 'utf8'; # allow even illegal characters
  return pack "U", $ord;
} # charnames

sub import
{
  shift; ## ignore class name

  if (not @_) {
    carp("`use charnames' needs explicit imports list");
  }
  $^H |= $charnames::hint_bits;
  $^H{charnames} = \&charnames ;

  ##
  ## fill %h keys with our @_ args.
  ##
  my ($promote, %h, @args) = (0);
  while (@_ and $_ = shift) {
    if ($_ eq ":alias") {
      @_ or
	croak ":alias needs an argument in charnames";
      my $alias = shift;
      if (ref $alias) {
	ref $alias eq "HASH" or
	  croak "Only HASH reference supported as argument to :alias";
	alias ($alias);
	next;
      }
      if ($alias =~ m{:(\w+)$}) {
	$1 eq "full" || $1 eq "short" and
	  croak ":alias cannot use existing pragma :$1 (reversed order?)";
	alias_file ($1) and $promote = 1;
	next;
      }
      alias_file ($alias);
      next;
    }
    if (m/^:/ and ! ($_ eq ":full" || $_ eq ":short")) {
      warn "unsupported special '$_' in charnames";
      next;
    }
    push @args, $_;
  }
  @args == 0 && $promote and @args = (":full");
  @h{@args} = (1) x @args;

  $^H{charnames_full} = delete $h{':full'};
  $^H{charnames_short} = delete $h{':short'};
  $^H{charnames_scripts} = [map uc, keys %h];

  ##
  ## If utf8? warnings are enabled, and some scripts were given,
  ## see if at least we can find one letter of each script.
  ##
  if (warnings::enabled('utf8') && @{$^H{charnames_scripts}}) {
    $txt = do "unicore/Name.pl" unless $txt;

    for my $script (@{$^H{charnames_scripts}}) {
      if (not $txt =~ m/\t\t$script (?:CAPITAL |SMALL )?LETTER /) {
	warnings::warn('utf8',  "No such script: '$script'");
      }
    }
  }
} # import

require Unicode::UCD; # for Unicode::UCD::_getcode()

my %viacode;

sub viacode
{
  if (@_ != 1) {
    carp "charnames::viacode() expects one argument";
    return ()
  }

  my $arg = shift;
  my $code = Unicode::UCD::_getcode($arg);

  my $hex;

  if (defined $code) {
    $hex = sprintf "%04X", $arg;
  } else {
    carp("unexpected arg \"$arg\" to charnames::viacode()");
    return;
  }

  if ($code > 0x10FFFF) {
    carp sprintf "Unicode characters only allocated up to U+10FFFF (you asked for U+%X)", $hex;
    return;
  }

  return $viacode{$hex} if exists $viacode{$hex};

  $txt = do "unicore/Name.pl" unless $txt;

  if ($txt =~ m/^$hex\t\t(.+)/m) {
    return $viacode{$hex} = $1;
  } else {
    return;
  }
} # viacode

my %vianame;

sub vianame
{
  if (@_ != 1) {
    carp "charnames::vianame() expects one name argument";
    return ()
  }

  my $arg = shift;

  return chr hex $1 if $arg =~ /^U\+([0-9a-fA-F]+)$/;

  return $vianame{$arg} if exists $vianame{$arg};

  $txt = do "unicore/Name.pl" unless $txt;

  my $pos = index $txt, "\t\t$arg\n";
  if ($[ <= $pos) {
    my $posLF = rindex $txt, "\n", $pos;
    (my $code = substr $txt, $posLF + 1, 6) =~ tr/\t//d;
    return $vianame{$arg} = hex $code;

    # If $pos is at the 1st line, $posLF must be $[ - 1 (not found);
    # then $posLF + 1 equals to $[ (at the beginning of $txt).
    # Otherwise $posLF is the position of "\n";
    # then $posLF + 1 must be the position of the next to "\n"
    # (the beginning of the line).
    # substr($txt, $posLF + 1, 6) may be "0000\t\t", "00A1\t\t",
    # "10300\t", "100000", etc. So we can get the code via removing TAB.
  } else {
    return;
  }
} # vianame


1;
__END__

=head1 NAME

charnames - define character names for C<\N{named}> string literal escapes

=head1 SYNOPSIS

  use charnames ':full';
  print "\N{GREEK SMALL LETTER SIGMA} is called sigma.\n";

  use charnames ':short';
  print "\N{greek:Sigma} is an upper-case sigma.\n";

  use charnames qw(cyrillic greek);
  print "\N{sigma} is Greek sigma, and \N{be} is Cyrillic b.\n";

  use charnames ":full", ":alias" => {
    e_ACUTE => "LATIN SMALL LETTER E WITH ACUTE",
  };
  print "\N{e_ACUTE} is a small letter e with an acute.\n";

  use charnames ();
  print charnames::viacode(0x1234); # prints "ETHIOPIC SYLLABLE SEE"
  printf "%04X", charnames::vianame("GOTHIC LETTER AHSA"); # prints "10330"

=head1 DESCRIPTION

Pragma C<use charnames> supports arguments C<:full>, C<:short>, script
names and customized aliases.  If C<:full> is present, for expansion of
C<\N{CHARNAME}>, the string C<CHARNAME> is first looked up in the list of
standard Unicode character names.  If C<:short> is present, and
C<CHARNAME> has the form C<SCRIPT:CNAME>, then C<CNAME> is looked up
as a letter in script C<SCRIPT>.  If pragma C<use charnames> is used
with script name arguments, then for C<\N{CHARNAME}> the name
C<CHARNAME> is looked up as a letter in the given scripts (in the
specified order). Customized aliases are explained in L</CUSTOM ALIASES>.

For lookup of C<CHARNAME> inside a given script C<SCRIPTNAME>
this pragma looks for the names

  SCRIPTNAME CAPITAL LETTER CHARNAME
  SCRIPTNAME SMALL LETTER CHARNAME
  SCRIPTNAME LETTER CHARNAME

in the table of standard Unicode names.  If C<CHARNAME> is lowercase,
then the C<CAPITAL> variant is ignored, otherwise the C<SMALL> variant
is ignored.

Note that C<\N{...}> is compile-time, it's a special form of string
constant used inside double-quoted strings: in other words, you cannot
use variables inside the C<\N{...}>.  If you want similar run-time
functionality, use charnames::vianame().

For the C0 and C1 control characters (U+0000..U+001F, U+0080..U+009F)
as of Unicode 3.1, there are no official Unicode names but you can use
instead the ISO 6429 names (LINE FEED, ESCAPE, and so forth).  In
Unicode 3.2 (as of Perl 5.8) some naming changes take place ISO 6429
has been updated, see L</ALIASES>.  Also note that the U+UU80, U+0081,
U+0084, and U+0099 do not have names even in ISO 6429.

Since the Unicode standard uses "U+HHHH", so can you: "\N{U+263a}"
is the Unicode smiley face, or "\N{WHITE SMILING FACE}".

=head1 CUSTOM TRANSLATORS

The mechanism of translation of C<\N{...}> escapes is general and not
hardwired into F<charnames.pm>.  A module can install custom
translations (inside the scope which C<use>s the module) with the
following magic incantation:

    use charnames ();		# for $charnames::hint_bits
    sub import {
	shift;
	$^H |= $charnames::hint_bits;
	$^H{charnames} = \&translator;
    }

Here translator() is a subroutine which takes C<CHARNAME> as an
argument, and returns text to insert into the string instead of the
C<\N{CHARNAME}> escape.  Since the text to insert should be different
in C<bytes> mode and out of it, the function should check the current
state of C<bytes>-flag as in:

    use bytes ();			# for $bytes::hint_bits
    sub translator {
	if ($^H & $bytes::hint_bits) {
	    return bytes_translator(@_);
	}
	else {
	    return utf8_translator(@_);
	}
    }

=head1 CUSTOM ALIASES

This version of charnames supports three mechanisms of adding local
or customized aliases to standard Unicode naming conventions (:full)

=head2 Anonymous hashes

    use charnames ":full", ":alias" => {
        e_ACUTE => "LATIN SMALL LETTER E WITH ACUTE",
        };
    my $str = "\N{e_ACUTE}";

=head2 Alias file

    use charnames ":full", ":alias" => "pro";

    will try to read "unicore/pro_alias.pl" from the @INC path. This
    file should return a list in plain perl:

    (
    A_GRAVE         => "LATIN CAPITAL LETTER A WITH GRAVE",
    A_CIRCUM        => "LATIN CAPITAL LETTER A WITH CIRCUMFLEX",
    A_DIAERES       => "LATIN CAPITAL LETTER A WITH DIAERESIS",
    A_TILDE         => "LATIN CAPITAL LETTER A WITH TILDE",
    A_BREVE         => "LATIN CAPITAL LETTER A WITH BREVE",
    A_RING          => "LATIN CAPITAL LETTER A WITH RING ABOVE",
    A_MACRON        => "LATIN CAPITAL LETTER A WITH MACRON",
    );

=head2 Alias shortcut

    use charnames ":alias" => ":pro";

    works exactly the same as the alias pairs, only this time,
    ":full" is inserted automatically as first argument (if no
    other argument is given).

=head1 charnames::viacode(code)

Returns the full name of the character indicated by the numeric code.
The example

    print charnames::viacode(0x2722);

prints "FOUR TEARDROP-SPOKED ASTERISK".

Returns undef if no name is known for the code.

This works only for the standard names, and does not yet apply
to custom translators.

Notice that the name returned for of U+FEFF is "ZERO WIDTH NO-BREAK
SPACE", not "BYTE ORDER MARK".

=head1 charnames::vianame(name)

Returns the code point indicated by the name.
The example

    printf "%04X", charnames::vianame("FOUR TEARDROP-SPOKED ASTERISK");

prints "2722".

Returns undef if the name is unknown.

This works only for the standard names, and does not yet apply
to custom translators.

=head1 ALIASES

A few aliases have been defined for convenience: instead of having
to use the official names

    LINE FEED (LF)
    FORM FEED (FF)
    CARRIAGE RETURN (CR)
    NEXT LINE (NEL)

(yes, with parentheses) one can use

    LINE FEED
    FORM FEED
    CARRIAGE RETURN
    NEXT LINE
    LF
    FF
    CR
    NEL

One can also use

    BYTE ORDER MARK
    BOM

and

    ZWNJ
    ZWJ

for ZERO WIDTH NON-JOINER and ZERO WIDTH JOINER.

For backward compatibility one can use the old names for
certain C0 and C1 controls

    old                         new

    HORIZONTAL TABULATION       CHARACTER TABULATION
    VERTICAL TABULATION         LINE TABULATION
    FILE SEPARATOR              INFORMATION SEPARATOR FOUR
    GROUP SEPARATOR             INFORMATION SEPARATOR THREE
    RECORD SEPARATOR            INFORMATION SEPARATOR TWO
    UNIT SEPARATOR              INFORMATION SEPARATOR ONE
    PARTIAL LINE DOWN           PARTIAL LINE FORWARD
    PARTIAL LINE UP             PARTIAL LINE BACKWARD

but the old names in addition to giving the character
will also give a warning about being deprecated.

=head1 ILLEGAL CHARACTERS

If you ask by name for a character that does not exist, a warning is
given and the Unicode I<replacement character> "\x{FFFD}" is returned.

If you ask by code for a character that does not exist, no warning is
given and C<undef> is returned.  (Though if you ask for a code point
past U+10FFFF you do get a warning.)

=head1 BUGS

Since evaluation of the translation function happens in a middle of
compilation (of a string literal), the translation function should not
do any C<eval>s or C<require>s.  This restriction should be lifted in
a future version of Perl.

=cut
Commit	Line	Data
423cee85	1	package charnames;
b177ca84 JF	2	use strict;
	3	use warnings;
	4	use Carp;
51cf30b6	5	use File::Spec;
35c0985d	6	our $VERSION = '1.02';
b75c8c73	7
d5448623	8	use bytes (); # for $bytes::hint_bits
9cfe5470	9	$charnames::hint_bits = 0x20000; # HINT_LOCALIZE_HH
423cee85	10
52ea3e69 JH	11	my %alias1 = (
	12	# Icky 3.2 names with parentheses.
	13	'LINE FEED' => 'LINE FEED (LF)',
	14	'FORM FEED' => 'FORM FEED (FF)',
	15	'CARRIAGE RETURN' => 'CARRIAGE RETURN (CR)',
	16	'NEXT LINE' => 'NEXT LINE (NEL)',
	17	# Convenience.
	18	'LF' => 'LINE FEED (LF)',
	19	'FF' => 'FORM FEED (FF)',
eb380778	20	'CR' => 'CARRIAGE RETURN (CR)',
51e9e896	21	'NEL' => 'NEXT LINE (NEL)',
24b5d5cc JH	22	# More convenience. For futher convencience,
	23	# it is suggested some way using using the NamesList
	24	# aliases is implemented.
	25	'ZWNJ' => 'ZERO WIDTH NON-JOINER',
	26	'ZWJ' => 'ZERO WIDTH JOINER',
52ea3e69 JH	27	'BOM' => 'BYTE ORDER MARK',
	28	);
	29
	30	my %alias2 = (
	31	# Pre-3.2 compatibility (only for the first 256 characters).
	32	'HORIZONTAL TABULATION' => 'CHARACTER TABULATION',
	33	'VERTICAL TABULATION' => 'LINE TABULATION',
	34	'FILE SEPARATOR' => 'INFORMATION SEPARATOR FOUR',
	35	'GROUP SEPARATOR' => 'INFORMATION SEPARATOR THREE',
	36	'RECORD SEPARATOR' => 'INFORMATION SEPARATOR TWO',
	37	'UNIT SEPARATOR' => 'INFORMATION SEPARATOR ONE',
	38	'PARTIAL LINE DOWN' => 'PARTIAL LINE FORWARD',
	39	'PARTIAL LINE UP' => 'PARTIAL LINE BACKWARD',
	40	);
	41
35c0985d MB	42	my %alias3 = (
	43	# User defined aliasses. Even more convenient :)
	44	);
423cee85 JH	45	my $txt;
423cee85 JH	46
35c0985d MB	47	sub alias (@)
	48	{
	49	@_ or return %alias3;
	50	my $alias = ref $_[0] ? $_[0] : { @_ };
	51	@alias3{keys %$alias} = values %$alias;
	52	} # alias
	53
	54	sub alias_file ($)
	55	{
51cf30b6 MB	56	my ($arg, $file) = @_;
	57	if (-f $arg && File::Spec->file_name_is_absolute ($arg)) {
	58	$file = $arg;
	59	}
	60	elsif ($arg =~ m/^\w+$/) {
	61	$file = "unicore/${arg}_alias.pl";
	62	}
	63	else {
	64	croak "Charnames alias files can only have identifier characters";
	65	}
35c0985d	66	if (my @alias = do $file) {
51cf30b6 MB	67	@alias == 1 && !defined $alias[0] and
	68	croak "$file cannot be used as alias file for charnames";
	69	@alias % 2 and
	70	croak "$file did not return a (valid) list of alias pairs";
35c0985d MB	71	alias (@alias);
	72	return (1);
	73	}
	74	0;
	75	} # alias_file
	76
423cee85	77	# This is not optimized in any way yet
b177ca84 JF	78	sub charnames
	79	{
	80	my $name = shift;
	81
52ea3e69	82	if (exists $alias1{$name}) {
35c0985d	83	$name = $alias1{$name};
52ea3e69	84	}
35c0985d MB	85	elsif (exists $alias2{$name}) {
	86	require warnings;
	87	warnings::warnif('deprecated', qq{Unicode character name "$name" is deprecated, use "$alias2{$name}" instead});
	88	$name = $alias2{$name};
	89	}
	90	elsif (exists $alias3{$name}) {
	91	$name = $alias3{$name};
52ea3e69	92	}
b177ca84	93
52ea3e69	94	my $ord;
423cee85	95	my @off;
52ea3e69 JH	96	my $fname;
	97
	98	if ($name eq "BYTE ORDER MARK") {
35c0985d MB	99	$fname = $name;
35c0985d MB	100	$ord = 0xFEFF;
52ea3e69	101	} else {
35c0985d MB	102	## Suck in the code/name list as a big string.
	103	## Lines look like:
	104	## "0052\t\tLATIN CAPITAL LETTER R\n"
	105	$txt = do "unicore/Name.pl" unless $txt;
	106
	107	## @off will hold the index into the code/name string of the start and
	108	## end of the name as we find it.
	109
a6d05634	110	## If :full, look for the name exactly
35c0985d MB	111	if ($^H{charnames_full} and $txt =~ /\t\t\Q$name\E$/m) {
	112	@off = ($-[0], $+[0]);
	113	}
	114
	115	## If we didn't get above, and :short allowed, look for the short name.
	116	## The short name is like "greek:Sigma"
	117	unless (@off) {
	118	if ($^H{charnames_short} and $name =~ /^(.+?):(.+)/s) {
	119	my ($script, $cname) = ($1, $2);
	120	my $case = $cname =~ /[[:upper:]]/ ? "CAPITAL" : "SMALL";
	121	if ($txt =~ m/\t\t\U$script\E (?:$case )?LETTER \U\Q$cname\E$/m) {
52ea3e69	122	@off = ($-[0], $+[0]);
35c0985d	123	}
423cee85	124	}
35c0985d	125	}
b177ca84	126
35c0985d MB	127	## If we still don't have it, check for the name among the loaded
	128	## scripts.
	129	if (not @off) {
	130	my $case = $name =~ /[[:upper:]]/ ? "CAPITAL" : "SMALL";
	131	for my $script (@{$^H{charnames_scripts}}) {
	132	if ($txt =~ m/\t\t$script (?:$case )?LETTER \U\Q$name\E$/m) {
	133	@off = ($-[0], $+[0]);
	134	last;
	135	}
52ea3e69	136	}
35c0985d MB	137	}
	138
	139	## If we don't have it by now, give up.
	140	unless (@off) {
	141	carp "Unknown charname '$name'";
	142	return "\x{FFFD}";
	143	}
	144
	145	##
	146	## Now know where in the string the name starts.
	147	## The code, in hex, is before that.
	148	##
	149	## The code can be 4-6 characters long, so we've got to sort of
	150	## go look for it, just after the newline that comes before $off[0].
	151	##
	152	## This would be much easier if unicore/Name.pl had info in
	153	## a name/code order, instead of code/name order.
	154	##
	155	## The +1 after the rindex() is to skip past the newline we're finding,
	156	## or, if the rindex() fails, to put us to an offset of zero.
	157	##
	158	my $hexstart = rindex($txt, "\n", $off[0]) + 1;
	159
	160	## we know where it starts, so turn into number -
	161	## the ordinal for the char.
	162	$ord = hex substr($txt, $hexstart, $off[0] - $hexstart);
423cee85	163	}
b177ca84	164
d5448623	165	if ($^H & $bytes::hint_bits) { # "use bytes" in effect?
8058d7ab	166	use bytes;
d41ff1b8	167	return chr $ord if $ord <= 255;
f0175764	168	my $hex = sprintf "%04x", $ord;
52ea3e69	169	if (not defined $fname) {
35c0985d	170	$fname = substr $txt, $off[0] + 2, $off[1] - $off[0] - 2;
52ea3e69	171	}
f0175764	172	croak "Character 0x$hex with name '$fname' is above 0xFF";
423cee85	173	}
f0175764	174
52ea3e69	175	no warnings 'utf8'; # allow even illegal characters
bfa383d6	176	return pack "U", $ord;
35c0985d	177	} # charnames
423cee85	178
b177ca84 JF	179	sub import
	180	{
	181	shift; ## ignore class name
	182
35c0985d MB	183	if (not @_) {
35c0985d MB	184	carp("`use charnames' needs explicit imports list");
b177ca84	185	}
d5448623	186	$^H \|= $charnames::hint_bits;
423cee85	187	$^H{charnames} = \&charnames ;
b177ca84 JF	188
	189	##
	190	## fill %h keys with our @_ args.
	191	##
35c0985d MB	192	my ($promote, %h, @args) = (0);
35c0985d MB	193	while (@_ and $_ = shift) {
51cf30b6 MB	194	if ($_ eq ":alias") {
	195	@_ or
	196	croak ":alias needs an argument in charnames";
35c0985d MB	197	my $alias = shift;
	198	if (ref $alias) {
	199	ref $alias eq "HASH" or
51cf30b6	200	croak "Only HASH reference supported as argument to :alias";
35c0985d MB	201	alias ($alias);
	202	next;
	203	}
51cf30b6 MB	204	if ($alias =~ m{:(\w+)$}) {
	205	$1 eq "full" \|\| $1 eq "short" and
	206	croak ":alias cannot use existing pragma :$1 (reversed order?)";
	207	alias_file ($1) and $promote = 1;
	208	next;
35c0985d	209	}
51cf30b6 MB	210	alias_file ($alias);
	211	next;
	212	}
	213	if (m/^:/ and ! ($_ eq ":full" \|\| $_ eq ":short")) {
	214	warn "unsupported special '$_' in charnames";
	215	next;
35c0985d MB	216	}
	217	push @args, $_;
	218	}
	219	@args == 0 && $promote and @args = (":full");
	220	@h{@args} = (1) x @args;
b177ca84	221
423cee85 JH	222	$^H{charnames_full} = delete $h{':full'};
	223	$^H{charnames_short} = delete $h{':short'};
	224	$^H{charnames_scripts} = [map uc, keys %h];
b177ca84 JF	225
	226	##
	227	## If utf8? warnings are enabled, and some scripts were given,
	228	## see if at least we can find one letter of each script.
	229	##
35c0985d MB	230	if (warnings::enabled('utf8') && @{$^H{charnames_scripts}}) {
	231	$txt = do "unicore/Name.pl" unless $txt;
	232
	233	for my $script (@{$^H{charnames_scripts}}) {
	234	if (not $txt =~ m/\t\t$script (?:CAPITAL \|SMALL )?LETTER /) {
	235	warnings::warn('utf8', "No such script: '$script'");
b177ca84	236	}
35c0985d	237	}
bd62941a	238	}
35c0985d	239	} # import
423cee85	240
f0175764 JH	241	require Unicode::UCD; # for Unicode::UCD::_getcode()
f0175764 JH	242
4e2cda5d JH	243	my %viacode;
4e2cda5d JH	244
b177ca84 JF	245	sub viacode
b177ca84 JF	246	{
35c0985d MB	247	if (@_ != 1) {
	248	carp "charnames::viacode() expects one argument";
	249	return ()
	250	}
f0175764	251
35c0985d MB	252	my $arg = shift;
35c0985d MB	253	my $code = Unicode::UCD::_getcode($arg);
b177ca84	254
35c0985d	255	my $hex;
f0175764	256
35c0985d MB	257	if (defined $code) {
	258	$hex = sprintf "%04X", $arg;
	259	} else {
	260	carp("unexpected arg \"$arg\" to charnames::viacode()");
	261	return;
	262	}
b177ca84	263
35c0985d MB	264	if ($code > 0x10FFFF) {
	265	carp sprintf "Unicode characters only allocated up to U+10FFFF (you asked for U+%X)", $hex;
	266	return;
	267	}
f0175764	268
35c0985d	269	return $viacode{$hex} if exists $viacode{$hex};
4e2cda5d	270
35c0985d	271	$txt = do "unicore/Name.pl" unless $txt;
b177ca84	272
35c0985d MB	273	if ($txt =~ m/^$hex\t\t(.+)/m) {
	274	return $viacode{$hex} = $1;
	275	} else {
	276	return;
	277	}
	278	} # viacode
daf0d493	279
4e2cda5d JH	280	my %vianame;
4e2cda5d JH	281
daf0d493 JH	282	sub vianame
daf0d493 JH	283	{
35c0985d MB	284	if (@_ != 1) {
	285	carp "charnames::vianame() expects one name argument";
	286	return ()
	287	}
daf0d493	288
35c0985d	289	my $arg = shift;
daf0d493	290
35c0985d	291	return chr hex $1 if $arg =~ /^U\+([0-9a-fA-F]+)$/;
dbc0d4f2	292
35c0985d	293	return $vianame{$arg} if exists $vianame{$arg};
4e2cda5d	294
35c0985d	295	$txt = do "unicore/Name.pl" unless $txt;
daf0d493	296
35c0985d MB	297	my $pos = index $txt, "\t\t$arg\n";
	298	if ($[ <= $pos) {
	299	my $posLF = rindex $txt, "\n", $pos;
	300	(my $code = substr $txt, $posLF + 1, 6) =~ tr/\t//d;
	301	return $vianame{$arg} = hex $code;
	302
	303	# If $pos is at the 1st line, $posLF must be $[ - 1 (not found);
	304	# then $posLF + 1 equals to $[ (at the beginning of $txt).
	305	# Otherwise $posLF is the position of "\n";
	306	# then $posLF + 1 must be the position of the next to "\n"
	307	# (the beginning of the line).
	308	# substr($txt, $posLF + 1, 6) may be "0000\t\t", "00A1\t\t",
	309	# "10300\t", "100000", etc. So we can get the code via removing TAB.
	310	} else {
	311	return;
	312	}
	313	} # vianame
b177ca84	314
423cee85 JH	315
	316	1;
	317	__END__
	318
	319	=head1 NAME
	320
274085e3	321	charnames - define character names for C<\N{named}> string literal escapes
423cee85 JH	322
	323	=head1 SYNOPSIS
	324
	325	use charnames ':full';
4a2d328f	326	print "\N{GREEK SMALL LETTER SIGMA} is called sigma.\n";
423cee85 JH	327
423cee85 JH	328	use charnames ':short';
4a2d328f	329	print "\N{greek:Sigma} is an upper-case sigma.\n";
423cee85 JH	330
423cee85 JH	331	use charnames qw(cyrillic greek);
4a2d328f	332	print "\N{sigma} is Greek sigma, and \N{be} is Cyrillic b.\n";
423cee85	333
35c0985d MB	334	use charnames ":full", ":alias" => {
35c0985d MB	335	e_ACUTE => "LATIN SMALL LETTER E WITH ACUTE",
76ae0c45	336	};
35c0985d MB	337	print "\N{e_ACUTE} is a small letter e with an acute.\n";
35c0985d MB	338
76ae0c45	339	use charnames ();
a23c04e4 JH	340	print charnames::viacode(0x1234); # prints "ETHIOPIC SYLLABLE SEE"
a23c04e4 JH	341	printf "%04X", charnames::vianame("GOTHIC LETTER AHSA"); # prints "10330"
b177ca84	342
423cee85 JH	343	=head1 DESCRIPTION
423cee85 JH	344
35c0985d MB	345	Pragma C<use charnames> supports arguments C<:full>, C<:short>, script
35c0985d MB	346	names and customized aliases. If C<:full> is present, for expansion of
76ae0c45 RGS	347	C<\N{CHARNAME}>, the string C<CHARNAME> is first looked up in the list of
76ae0c45 RGS	348	standard Unicode character names. If C<:short> is present, and
423cee85 JH	349	C<CHARNAME> has the form C<SCRIPT:CNAME>, then C<CNAME> is looked up
423cee85 JH	350	as a letter in script C<SCRIPT>. If pragma C<use charnames> is used
a191c821	351	with script name arguments, then for C<\N{CHARNAME}> the name
423cee85	352	C<CHARNAME> is looked up as a letter in the given scripts (in the
35c0985d	353	specified order). Customized aliases are explained in L</CUSTOM ALIASES>.
423cee85 JH	354
423cee85 JH	355	For lookup of C<CHARNAME> inside a given script C<SCRIPTNAME>
d5448623	356	this pragma looks for the names
423cee85 JH	357
	358	SCRIPTNAME CAPITAL LETTER CHARNAME
	359	SCRIPTNAME SMALL LETTER CHARNAME
	360	SCRIPTNAME LETTER CHARNAME
	361
	362	in the table of standard Unicode names. If C<CHARNAME> is lowercase,
daf0d493 JH	363	then the C<CAPITAL> variant is ignored, otherwise the C<SMALL> variant
	364	is ignored.
	365
	366	Note that C<\N{...}> is compile-time, it's a special form of string
	367	constant used inside double-quoted strings: in other words, you cannot
4e2cda5d	368	use variables inside the C<\N{...}>. If you want similar run-time
daf0d493	369	functionality, use charnames::vianame().
423cee85	370
301a3cda	371	For the C0 and C1 control characters (U+0000..U+001F, U+0080..U+009F)
dbc0d4f2 JH	372	as of Unicode 3.1, there are no official Unicode names but you can use
	373	instead the ISO 6429 names (LINE FEED, ESCAPE, and so forth). In
	374	Unicode 3.2 (as of Perl 5.8) some naming changes take place ISO 6429
	375	has been updated, see L</ALIASES>. Also note that the U+UU80, U+0081,
	376	U+0084, and U+0099 do not have names even in ISO 6429.
	377
	378	Since the Unicode standard uses "U+HHHH", so can you: "\N{U+263a}"
	379	is the Unicode smiley face, or "\N{WHITE SMILING FACE}".
301a3cda	380
423cee85 JH	381	=head1 CUSTOM TRANSLATORS
423cee85 JH	382
d5448623	383	The mechanism of translation of C<\N{...}> escapes is general and not
423cee85	384	hardwired into F<charnames.pm>. A module can install custom
d5448623	385	translations (inside the scope which C<use>s the module) with the
423cee85 JH	386	following magic incantation:
423cee85 JH	387
d5448623 GS	388	use charnames (); # for $charnames::hint_bits
	389	sub import {
	390	shift;
	391	$^H \|= $charnames::hint_bits;
	392	$^H{charnames} = \&translator;
	393	}
423cee85 JH	394
	395	Here translator() is a subroutine which takes C<CHARNAME> as an
	396	argument, and returns text to insert into the string instead of the
4a2d328f	397	C<\N{CHARNAME}> escape. Since the text to insert should be different
d5448623 GS	398	in C<bytes> mode and out of it, the function should check the current
	399	state of C<bytes>-flag as in:
	400
	401	use bytes (); # for $bytes::hint_bits
	402	sub translator {
	403	if ($^H & $bytes::hint_bits) {
	404	return bytes_translator(@_);
	405	}
	406	else {
	407	return utf8_translator(@_);
	408	}
423cee85	409	}
423cee85	410
35c0985d MB	411	=head1 CUSTOM ALIASES
	412
	413	This version of charnames supports three mechanisms of adding local
	414	or customized aliases to standard Unicode naming conventions (:full)
	415
	416	=head2 Anonymous hashes
	417
	418	use charnames ":full", ":alias" => {
	419	e_ACUTE => "LATIN SMALL LETTER E WITH ACUTE",
	420	};
	421	my $str = "\N{e_ACUTE}";
	422
	423	=head2 Alias file
	424
	425	use charnames ":full", ":alias" => "pro";
	426
	427	will try to read "unicore/pro_alias.pl" from the @INC path. This
	428	file should return a list in plain perl:
	429
	430	(
	431	A_GRAVE => "LATIN CAPITAL LETTER A WITH GRAVE",
	432	A_CIRCUM => "LATIN CAPITAL LETTER A WITH CIRCUMFLEX",
	433	A_DIAERES => "LATIN CAPITAL LETTER A WITH DIAERESIS",
	434	A_TILDE => "LATIN CAPITAL LETTER A WITH TILDE",
	435	A_BREVE => "LATIN CAPITAL LETTER A WITH BREVE",
	436	A_RING => "LATIN CAPITAL LETTER A WITH RING ABOVE",
	437	A_MACRON => "LATIN CAPITAL LETTER A WITH MACRON",
	438	);
	439
	440	=head2 Alias shortcut
	441
	442	use charnames ":alias" => ":pro";
	443
	444	works exactly the same as the alias pairs, only this time,
	445	":full" is inserted automatically as first argument (if no
	446	other argument is given).
	447
b177ca84 JF	448	=head1 charnames::viacode(code)
	449
	450	Returns the full name of the character indicated by the numeric code.
	451	The example
	452
	453	print charnames::viacode(0x2722);
	454
	455	prints "FOUR TEARDROP-SPOKED ASTERISK".
	456
daf0d493 JH	457	Returns undef if no name is known for the code.
daf0d493 JH	458
35c0985d	459	This works only for the standard names, and does not yet apply
daf0d493 JH	460	to custom translators.
daf0d493 JH	461
274085e3 PN	462	Notice that the name returned for of U+FEFF is "ZERO WIDTH NO-BREAK
	463	SPACE", not "BYTE ORDER MARK".
	464
eb6a2339	465	=head1 charnames::vianame(name)
daf0d493 JH	466
	467	Returns the code point indicated by the name.
	468	The example
	469
	470	printf "%04X", charnames::vianame("FOUR TEARDROP-SPOKED ASTERISK");
	471
	472	prints "2722".
	473
eb6a2339	474	Returns undef if the name is unknown.
b177ca84	475
35c0985d	476	This works only for the standard names, and does not yet apply
b177ca84 JF	477	to custom translators.
b177ca84 JF	478
52ea3e69 JH	479	=head1 ALIASES
	480
	481	A few aliases have been defined for convenience: instead of having
	482	to use the official names
	483
	484	LINE FEED (LF)
	485	FORM FEED (FF)
	486	CARRIAGE RETURN (CR)
	487	NEXT LINE (NEL)
	488
	489	(yes, with parentheses) one can use
	490
	491	LINE FEED
	492	FORM FEED
	493	CARRIAGE RETURN
	494	NEXT LINE
	495	LF
	496	FF
	497	CR
	498	NEL
	499
	500	One can also use
	501
	502	BYTE ORDER MARK
	503	BOM
	504
24b5d5cc JH	505	and
	506
	507	ZWNJ
	508	ZWJ
	509
	510	for ZERO WIDTH NON-JOINER and ZERO WIDTH JOINER.
52ea3e69 JH	511
	512	For backward compatibility one can use the old names for
	513	certain C0 and C1 controls
	514
	515	old new
	516
	517	HORIZONTAL TABULATION CHARACTER TABULATION
	518	VERTICAL TABULATION LINE TABULATION
	519	FILE SEPARATOR INFORMATION SEPARATOR FOUR
	520	GROUP SEPARATOR INFORMATION SEPARATOR THREE
	521	RECORD SEPARATOR INFORMATION SEPARATOR TWO
	522	UNIT SEPARATOR INFORMATION SEPARATOR ONE
	523	PARTIAL LINE DOWN PARTIAL LINE FORWARD
	524	PARTIAL LINE UP PARTIAL LINE BACKWARD
	525
	526	but the old names in addition to giving the character
	527	will also give a warning about being deprecated.
	528
f0175764 JH	529	=head1 ILLEGAL CHARACTERS
f0175764 JH	530
00d835f2 JH	531	If you ask by name for a character that does not exist, a warning is
	532	given and the Unicode I<replacement character> "\x{FFFD}" is returned.
	533
	534	If you ask by code for a character that does not exist, no warning is
	535	given and C<undef> is returned. (Though if you ask for a code point
	536	past U+10FFFF you do get a warning.)
f0175764	537
423cee85 JH	538	=head1 BUGS
	539
	540	Since evaluation of the translation function happens in a middle of
	541	compilation (of a string literal), the translation function should not
	542	do any C<eval>s or C<require>s. This restriction should be lifted in
	543	a future version of Perl.
	544
	545	=cut