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authorJeffrey Friedl <jfriedl@regex.info>2001-11-12 16:36:21 -0800
committerJarkko Hietaniemi <jhi@iki.fi>2001-11-13 12:59:11 +0000
commitb177ca842995c54b969c92fd2f640f7cea6af4f1 (patch)
tree30e34165ff30262bf77470a6fafcee99172bf3c1 /lib/charnames.pm
parentfe12c0e8d6c27f5429e57856f94fd9369b44eabc (diff)
downloadperl-b177ca842995c54b969c92fd2f640f7cea6af4f1.tar.gz
lib/charnames.pm
Message-Id: <200111130836.fAD8aLG76010@ventrue.corp.yahoo.com> p4raw-id: //depot/perl@12968
Diffstat (limited to 'lib/charnames.pm')
-rw-r--r--lib/charnames.pm149
1 files changed, 123 insertions, 26 deletions
diff --git a/lib/charnames.pm b/lib/charnames.pm
index 70d6d17f33..b93f723332 100644
--- a/lib/charnames.pm
+++ b/lib/charnames.pm
@@ -1,23 +1,37 @@
package charnames;
-
-our $VERSION = '1.00';
+use strict;
+use warnings;
+use Carp;
+our $VERSION = '1.01';
use bytes (); # for $bytes::hint_bits
-use warnings();
$charnames::hint_bits = 0x20000;
my $txt;
# This is not optimized in any way yet
-sub charnames {
- $name = shift;
+sub charnames
+{
+ my $name = shift;
+
+ ## 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 $txt;
+
+ ## @off will hold the index into the code/name string of the start and
+ ## end of the name as we find it.
my @off;
+
+ ## If :full, look for the the name exactly
if ($^H{charnames_full} and $txt =~ /\t\t$name$/m) {
@off = ($-[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 $name =~ /^(.*?):(.*)/s) {
+ if ($^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$cname$/m) {
@@ -25,19 +39,42 @@ sub charnames {
}
}
}
- unless (@off) {
- my $case = ( $name =~ /[[:upper:]]/ ? "CAPITAL" : "SMALL");
- for ( @{$^H{charnames_scripts}} ) {
- (@off = ($-[0], $+[0])), last
- if $txt =~ m/\t\t$_ (?:$case )?LETTER \U$name$/m;
- }
+
+ ## 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 (?:$case )?LETTER \U$name$/m) {
+ @off = ($-[0], $+[0]);
+ last;
+ }
+ }
}
+
+ ## If we don't have it by now, give up.
die "Unknown charname '$name'" unless @off;
- my $hexlen = 4; # Unicode guarantees 4-, 5-, or 6-digit format
- $hexlen++ while
- $hexlen < 6 && substr($txt, $off[0] - $hexlen - 1, 1) =~ /[0-9a-f]/;
- my $ord = hex substr $txt, $off[0] - $hexlen, $hexlen;
+ ##
+ ## Now know where in the string the name starts.
+ ## The code, in hex, is befor 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.
+ my $ord = hex substr($txt, $hexstart, $off[0] - $hexstart);
+
if ($^H & $bytes::hint_bits) { # "use bytes" in effect?
use bytes;
return chr $ord if $ord <= 255;
@@ -48,32 +85,76 @@ sub charnames {
return pack "U", $ord;
}
-sub import {
- shift;
- die "`use charnames' needs explicit imports list" unless @_;
+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 %h;
@h{@_} = (1) x @_;
+
$^H{charnames_full} = delete $h{':full'};
$^H{charnames_short} = delete $h{':short'};
$^H{charnames_scripts} = [map uc, keys %h];
- if (warnings::enabled('utf8') && @{$^H{charnames_scripts}}) {
- $txt = do "unicore/Name.pl" unless $txt;
- for (@{$^H{charnames_scripts}}) {
- warnings::warn('utf8', "No such script: '$_'") unless
- $txt =~ m/\t\t$_ (?:CAPITAL |SMALL )?LETTER /;
- }
+
+ ##
+ ## 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'");
+ }
+ }
}
}
+sub viacode
+{
+ if (@_ != 1) {
+ carp "charnames::viacode() expects one numeric value";
+ return ()
+ }
+ my $arg = shift;
+
+ my $hex;
+ if ($arg =~ m/^[0-9]+$/) {
+ $hex = sprintf "%04X", $arg;
+ } else {
+ carp("unexpected arg \"$arg\" to charnames::viacode()");
+ return ();
+ }
+
+ $txt = do "unicore/Name.pl" unless $txt;
+
+ if ($txt =~ m/^$hex\t\t(.+)/m) {
+ return $1;
+ } else {
+ return ();
+ }
+}
+
1;
__END__
=head1 NAME
-charnames - define character names for C<\N{named}> string literal escape.
+charnames - define character names for C<\N{named}> string literal escapes.
=head1 SYNOPSIS
@@ -86,6 +167,8 @@ charnames - define character names for C<\N{named}> string literal escape.
use charnames qw(cyrillic greek);
print "\N{sigma} is Greek sigma, and \N{be} is Cyrillic b.\n";
+ print charname::viacode(0x1234); # prints "ETHIOPIC SYLLABLE SEE"
+
=head1 DESCRIPTION
Pragma C<use charnames> supports arguments C<:full>, C<:short> and
@@ -139,6 +222,20 @@ state of C<bytes>-flag as in:
}
}
+=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 nothing if no name is known for the code.
+
+This works only for the standard names, and does not yet aply
+to custom translators.
+
=head1 BUGS
Since evaluation of the translation function happens in a middle of