From 8f45336102805af6d836a6ffcffc3583bfa2add8 Mon Sep 17 00:00:00 2001
From: Mischa POSLAWSKY <perl@shiar.org>
Date: Sun, 19 Apr 2009 19:25:48 +0000
Subject: [PATCH] charset: crop shared character ranges

---
 charset.plp | 60 ++++++++++++++++++++++++++++++++++++++++-------------
 1 file changed, 46 insertions(+), 14 deletions(-)

diff --git a/charset.plp b/charset.plp
index 25b69b9..e5ca8bf 100644
--- a/charset.plp
+++ b/charset.plp
@@ -31,7 +31,8 @@ use Encode qw(decode resolve_alias);
 # (~16x faster than decoding in loop;
 #  substr strings is twice as fast as splitting to an array)
 my %ALIAS = (
-	default => [qw(utf-8 iso-8859-1 cp437)],
+#	default => [qw(unicode utf-8 iso-8859-1 cp437 -cp1252- --iso-8859-15- -koi8-f)],
+	default => [qw(unicode utf-8 iso-8859-1 -cp1252- --iso-8859-15- cp437 -cp850)],
 	0 => [qw(cp437 cp863)],
 	1 => [qw(iso-8859-1 cp1252 MacRoman cp850)],
 	2 => [qw(iso-8859-2 cp1250 cp852 MacCentralEurRoman MacCroatian MacRumanian)],
@@ -39,16 +40,47 @@ my %ALIAS = (
 	7 => [qw(iso-8859-7 cp1253 MacGreek cp737 cp869)],
 	8 => [qw(iso-8859-8 cp1255 MacHebrew cp862)],
 );
-my @request = grep { defined } map {
-	$_ ? (resolve_alias($_) or print("Encoding $_ unknown") && ()) : ();
+my @request = map {
+	if (my $input = $_) {
+		my %row = (offset => 0);
+		my $endpoint = 255;
+		if ($input =~ s/^--//) {
+			$row{offset} = $endpoint > 160 ? 160 : 48;
+		}
+		elsif ($input =~ s/^-//) {
+			$row{offset} = $endpoint > 128 ? 128 : 32;
+		}
+		if ($input =~ s/-$//) {
+			$endpoint = $row{offset} ? $row{offset} < 160 ? 159 : 191 : 127;
+		}
+		if ($row{set} = resolve_alias($input)) {
+			if ($row{set} eq 'Internal') {
+				$row{table} = ' 'x512;
+				$row{set} = 'Unicode BMP';
+			}
+			elsif ($row{set} eq 'utf-8-strict') {
+				$row{table} = undef;
+				$row{set} = 'UTF-8';
+			}
+			else {
+				$row{table} = decode($row{set}, pack 'C*', $row{offset} .. $endpoint);
+			}
+		}
+		else {
+			print "<p>Encoding $input unknown</p>\n";
+		}
+		\%row;
+	}
+	else {
+		();
+	}
 } map { defined $ALIAS{$_} ? @{ $ALIAS{$_} } : $_ }
 	$ENV{PATH_INFO} =~ /\w/ ? split(m{[/+\s]}, $ENV{PATH_INFO}) : 'default';
-my @tables = map { $_ eq 'utf-8-strict' ? undef : $_ eq 'Internal' ? ' 'x512 : decode($_, pack 'C*', 0..255) } @request;
 my $NOCHAR = chr 0xFFFD;
 
-for my $cp437 (grep {$request[$_] eq 'cp437'} 0 .. $#request) {
-	substr($tables[$cp437], 237, 1) = pack 'U*', 0x3D5; # phi sign
-	substr($tables[$cp437], 0, 32) = pack 'U*', map {hex} qw(
+for my $cp437 (grep {$request[$_]->{set} eq 'cp437'} 0 .. $#request) {
+	substr($request[$cp437]->{table}, 237, 1) = pack 'U*', 0x3D5; # phi sign
+	substr($request[$cp437]->{table}, 0, 32) = pack 'U*', map {hex} qw(
 		2007 263A 263B 2665 2666 2663 2660 2022 25D8 25CB 25D9 2642 2640 266A 266B 263C
 		25BA 25C4 2195 203C 00B6 00A7 25AC 21A8 2191 2193 2192 2190 221F 2194 25B2 25BC
 	);
@@ -350,9 +382,9 @@ sub printcell_utf8 {
 print "<ul>\n";
 
 my @nibble = (0..9, 'A'..'F');
-for my $tablenum (0 .. $#tables) {
+for my $row (@request) {
 	print '<li><table class="glyphs">';
-	printf '<caption>%s</caption>', $request[$tablenum] eq 'utf-8-strict' ? 'UTF-8' : $request[$tablenum];
+	printf '<caption>%s</caption>', $row->{set};
 	print '<col>';
 	for my $section (qw{thead}) {
 		print "<$section><tr><th>↱";
@@ -360,19 +392,19 @@ for my $tablenum (0 .. $#tables) {
 		print "\n";
 	}
 	print '<tbody>';
-	for my $msb (0 .. (length($tables[$tablenum]) || 256) - 1 >> 4) {
-		printf '<tr><th>%X', $msb;
+	for my $msb (0 .. (length($row->{table}) || 256) - 1 >> 4) {
+		printf '<tr><th>%X', $msb + ($row->{offset} >> 4);
 		for my $lsb (0 .. $#nibble) {
-			if ($request[$tablenum] eq 'utf-8-strict') {
+			if ($row->{set} eq 'UTF-8') {
 				printcell_utf8(($msb<<4) + $lsb);
 				next;
 			}
-			elsif ($request[$tablenum] eq 'Internal') {
+			elsif ($row->{set} eq 'Unicode BMP') {
 				printcell_unicode(($msb<<4) + $lsb);
 				next;
 			}
 
-			my $glyph = substr $tables[$tablenum], ($msb<<4) + $lsb, 1;
+			my $glyph = substr $row->{table}, ($msb<<4) + $lsb, 1;
 			if ($glyph eq $NOCHAR) {
 				print '<td>';
 				next;
-- 
2.30.0