Enhance the open pragma to support :utf8, :locale,

and :encoding directly as special cases, and rename
the INOUT to IO.

p4raw-id: //depot/perl@12933

2 files changed, 92 insertions, 20 deletions

diff --git a/lib/open.pm b/lib/open.pm
index d8a6350c1d..1c42b8aee9 100644
--- a/lib/open.pm
+++ b/lib/open.pm
@@ -25,8 +25,12 @@ sub _get_locale_encoding {
 	    } elsif ($ENV{LANG} =~ /^([^.]+)\.([^.]+)$/) {
 		($country_language, $locale_encoding) = ($1, $2);
 	    }
-	} else {
-	    # Could do heuristics based on the country and language
+	} elsif (not $locale_encoding) {
+	    if ($ENV{LC_ALL} =~ /\butf-?8\b/i ||
+		$ENV{LANG}   =~ /\butf-?8\b/i) {
+		$locale_encoding = 'utf8';
+	    }
+	    # Could do more heuristics based on the country and language
 	    # parts of LC_ALL and LANG (the parts before the dot (if any)),
 	    # since we have Locale::Country and Locale::Language available.
 	    # TODO: get a database of Language -> Encoding mappings
@@ -37,11 +41,11 @@ sub _get_locale_encoding {
 	    $locale_encoding eq 'euc' &&
 	    defined $country_language) {
 	    if ($country_language =~ /^ja_JP|japan(?:ese)?$/i) {
-		$locale_encoding = 'eucjp';
+		$locale_encoding = 'euc-jp';
 	    } elsif ($country_language =~ /^ko_KR|korean?$/i) {
-		$locale_encoding = 'euckr';
+		$locale_encoding = 'euc-kr';
 	    } elsif ($country_language =~ /^zh_TW|taiwan(?:ese)?$/i) {
-		$locale_encoding = 'euctw';
+		$locale_encoding = 'euc-tw';
 	    }
 	    croak "Locale encoding 'euc' too ambiguous"
 		if $locale_encoding eq 'euc';
@@ -56,9 +60,15 @@ sub import {
     my ($in,$out) = split(/\0/,(${^OPEN} || "\0"), -1);
     while (@args) {
 	my $type = shift(@args);
-	my $discp = shift(@args);
+	my $dscp;
+	if ($type =~ /^:?(utf8|locale|encoding\(.+\))$/) {
+	    $type = 'IO';
+	    $dscp = ":$1";
+	} else {
+	    $dscp = shift(@args);
+	}
 	my @val;
-	foreach my $layer (split(/\s+/,$discp)) {
+	foreach my $layer (split(/\s+/,$dscp)) {
             $layer =~ s/^://;
 	    if ($layer eq 'locale') {
 		use Encode;
@@ -88,14 +98,14 @@ sub import {
 	elsif ($type eq 'OUT') {
 	    $out = join(' ',@val);
 	}
-	elsif ($type eq 'INOUT') {
+	elsif ($type eq 'IO') {
 	    $in = $out = join(' ',@val);
 	}
 	else {
 	    croak "Unknown discipline class '$type'";
 	}
     }
-    ${^OPEN} = join('\0',$in,$out);
+    ${^OPEN} = join("\0",$in,$out);
 }
 
 1;
@@ -107,8 +117,15 @@ open - perl pragma to set default disciplines for input and output
 
 =head1 SYNOPSIS
 
-    use open IN => ":crlf", OUT => ":raw";
-    use open INOUT => ":utf8";
+    use open IN  => ":crlf", OUT => ":raw";
+    use open OUT => ':utf8';
+    use open IO  => ":encoding(iso-8859-7)";
+
+    use open IO  => ':locale';
+  
+    use open ':utf8';
+    use open ':locale';
+    use open ':encoding(iso-8859-7)';
 
 =head1 DESCRIPTION
 
@@ -124,6 +141,41 @@ I/O operations.  Any open(), readpipe() (aka qx//) and similar
 operators found within the lexical scope of this pragma will use the
 declared defaults.
 
+With the C<IN> subpragma you can declare the default layers
+of input sterams, and with the C<OUT> subpragma you can declare
+the default layers of output streams.  With the C<IO>  subpragma
+you can control both input and output streams simultaneously.
+
+If you have a legacy encoding, you can use the C<:encoding(...)> tag.
+
+if you want to set your encoding disciplines based on your
+locale environment variables, you can use the C<:locale> tag.
+For example:
+
+    $ENV{LANG} = 'ru_RU.KOI8-R';
+    use open ':locale';
+    open(O, ">koi8");
+    print O chr(0x430); # Unicode CYRILLIC SMALL LETTER A = KOI8-R 0xC1
+    close O;
+    open(I, "<koi8");
+    printf "%#x\n", ord(<I>), "\n"; # this should print 0xC1
+    close I;
+
+These are equivalent
+
+    use open ':utf8';
+    use open IO => ':utf8';
+
+as are these
+
+    use open ':locale';
+    use open IO => ':locale';
+
+and these
+
+    use open ':encoding(iso-8859-7)';
+    use open IO => ':encoding(iso-8859-7)';
+
 When open() is given an explicit list of layers they are appended to
 the list declared using this pragma.
 
diff --git a/lib/open.t b/lib/open.t
index 88749d784b..3113eff747 100644
--- a/lib/open.t
+++ b/lib/open.t
@@ -5,7 +5,7 @@ BEGIN {
 	@INC = '../lib';
 }
 
-use Test::More tests => 12;
+use Test::More tests => 13;
 
 # open::import expects 'open' as its first argument, but it clashes with open()
 sub import {
@@ -44,7 +44,7 @@ like( $warn, qr/Unknown discipline layer/,
 # now load a real-looking locale
 $ENV{LC_ALL} = ' .utf8';
 import( 'IN', 'locale' );
-is( ${^OPEN}, ':utf8\0', 
+is( ${^OPEN}, ":utf8\0", 
 	'should set a valid locale layer' );
 
 # and see if it sets the magic variables appropriately
@@ -57,19 +57,39 @@ is( $^H{'open_IN'}, 'crlf', 'should have set crlf layer' );
 import( 'IN', ':raw' );
 is( $^H{'open_IN'}, 'raw', 'should have reset to raw layer' );
 
-# it dies if you don't set IN, OUT, or INOUT
+# it dies if you don't set IN, OUT, or IO
 eval { import( 'sideways', ':raw' ) };
 like( $@, qr/Unknown discipline class/, 'should croak with unknown class' );
 
 # but it handles them all so well together
-import( 'INOUT', ':raw :crlf' );
-is( ${^OPEN}, ':raw :crlf\0:raw :crlf', 
+import( 'IO', ':raw :crlf' );
+is( ${^OPEN}, ":raw :crlf\0:raw :crlf",
 	'should set multi types, multi disciplines' );
-is( $^H{'open_INOUT'}, 'crlf', 'should record last layer set in %^H' );
+is( $^H{'open_IO'}, 'crlf', 'should record last layer set in %^H' );
 
-__END__
-# this one won't run as $locale_encoding is already set
-# perhaps qx{} it, if it's important to run
+# the special :utf8 layer
+use open ':utf8';
+open(O, ">utf8");
+print O chr(0x100);
+close O;
+open(I, "<utf8");
+is(ord(<I>), 0x100, ":utf8");
+close I;
+
+# the test cases beyond __DATA__ need to be executed separately
+
+__DATA__
 $ENV{LC_ALL} = 'nonexistent.euc';
 eval { open::_get_locale_encoding() };
 like( $@, qr/too ambiguous/, 'should die with ambiguous locale encoding' );
+%%%
+# the special :locale layer
+$ENV{LANG} = 'ru_RU.KOI8-R';
+use open ':locale';
+open(O, ">koi8");
+print O chr(0x430); # Unicode CYRILLIC SMALL LETTER A = KOI8-R 0xC1
+close O;
+open(I, "<koi8");
+is(ord(<I>), 0xC1, ":locale");
+close I;
+%%%