integrate cfgperl changes#6224..6229 into mainline

p4raw-link: @6229 on //depot/cfgperl: 94f13a8fe911b4e5d658c1e8bb515599305c074c
p4raw-link: @6224 on //depot/cfgperl: 9e7db0fd3029ee5d3ce957e842a66c057eacd303

p4raw-id: //depot/perl@6352
p4raw-deleted: from //depot/cfgperl@6351 'delete in' lib/lib.pm
	(@5608..)
p4raw-integrated: from //depot/cfgperl@6351 'copy in' t/lib/english.t
	(@5586..) ext/Socket/Socket.pm (@5704..) README.hpux (@5972..)
	lib/English.pm (@6034..)
p4raw-integrated: from //depot/cfgperl@6228 'copy in' op.c (@6226..)
p4raw-branched: from //depot/cfgperl@6227 'branch in' lib/lib.pm.PL
p4raw-integrated: from //depot/cfgperl@6227 'copy in' Makefile.SH
	(@6182..) MANIFEST (@6192..)
p4raw-integrated: from //depot/cfgperl@6225 'merge in' embed.pl
	(@6221..)

1 files changed, 42 insertions, 12 deletions

diff --git a/lib/English.pm b/lib/English.pm
index f38c313beb..1ebc3de11d 100644
--- a/lib/English.pm
+++ b/lib/English.pm
@@ -9,6 +9,7 @@ English - use nice English (or awk) names for ugly punctuation variables
 
 =head1 SYNOPSIS
 
+    use English qw( -no_match_vars ) ;  # Avoids regex performance penalty
     use English;
     ...
     if ($ERRNO =~ /denied/) { ... }
@@ -27,29 +28,52 @@ $INPUT_RECORD_SEPARATOR if you are using the English module.
 
 See L<perlvar> for a complete list of these.
 
-=head1 BUGS
+=head1 PERFORMANCE
 
-This module provokes sizeable inefficiencies for regular expressions,
-due to unfortunate implementation details.  If performance matters,
-consider avoiding English.
+This module can provoke sizeable inefficiencies for regular expressions,
+due to unfortunate implementation details.  If performance matters in
+your application and you don't need $PREMATCH, $MATCH, or $POSTMATCH,
+try doing
+
+   use English qw( -no_match_vars ) ;
+
+.  B<It is especially important to do this in modules to avoid penalizing
+all applications which use them.>
 
 =cut
 
 no warnings;
 
+my $globbed_match ;
+
 # Grandfather $NAME import
 sub import {
     my $this = shift;
-    my @list = @_;
+    my @list = grep { ! /^-no_match_vars$/ } @_ ;
     local $Exporter::ExportLevel = 1;
+    if ( @_ == @list ) {
+        *EXPORT = \@COMPLETE_EXPORT ;
+        $globbed_match ||= (
+	    eval q{
+		*MATCH				= *&	;
+		*PREMATCH				= *`	;
+		*POSTMATCH				= *'	;
+		1 ;
+	       }
+	    || do {
+		require Carp ;
+		Carp::croak "Can't create English for match leftovers: $@" ;
+	    }
+	) ;
+    }
+    else {
+        *EXPORT = \@MINIMAL_EXPORT ;
+    }
     Exporter::import($this,grep {s/^\$/*/} @list);
 }
 
-@EXPORT = qw(
+@MINIMAL_EXPORT = qw(
 	*ARG
-	*MATCH
-	*PREMATCH
-	*POSTMATCH
 	*LAST_PAREN_MATCH
 	*INPUT_LINE_NUMBER
 	*NR
@@ -102,15 +126,21 @@ sub import {
 	@LAST_MATCH_END
 );
 
+
+@MATCH_EXPORT = qw(
+	*MATCH
+	*PREMATCH
+	*POSTMATCH
+);
+
+@COMPLETE_EXPORT = ( @MINIMAL_EXPORT, @MATCH_EXPORT ) ;
+
 # The ground of all being. @ARG is deprecated (5.005 makes @_ lexical)
 
 	*ARG					= *_	;
 
 # Matching.
 
-	*MATCH					= *&	;
-	*PREMATCH				= *`	;
-	*POSTMATCH				= *'	;
 	*LAST_PAREN_MATCH			= *+	;
 	*LAST_MATCH_START			= *-{ARRAY} ;
 	*LAST_MATCH_END				= *+{ARRAY} ;