X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FText%2FTabs.pm;h=933f917acdcb0b36c8768d13327776e3a3fde28e;hb=ee8c7f5465f003860e2347a2946abacac39bd9b9;hp=2481d81ec6b22f160fe5e141dd45c386c4f62dbf;hpb=cb1a09d0194fed9b905df7b04a4bc031d354609d;p=p5sagit%2Fp5-mst-13.2.git

diff --git a/lib/Text/Tabs.pm b/lib/Text/Tabs.pm
index 2481d81..933f917 100644
--- a/lib/Text/Tabs.pm
+++ b/lib/Text/Tabs.pm
@@ -1,43 +1,3 @@
-#
-# expand and unexpand tabs as per the unix expand and 
-# unexpand programs.
-#
-# expand and unexpand operate on arrays of lines.  Do not
-# feed strings that contain newlines to them.
-#
-# David Muir Sharnoff <muir@idiom.com>
-# 
-# Version: 9/21/95
-#
-
-=head1 NAME
-
-Text::Tabs -- expand and unexpand tabs
-
-=head1 SYNOPSIS
-
-	use Text::Tabs;
-	
-	#$tabstop = 8; # Defaults
-	print expand("Hello\tworld");
-	print unexpand("Hello,        world");
-	$tabstop = 4;
-	print join("\n",expand(split(/\n/,
-		"Hello\tworld,\nit's a nice day.\n"
-		)));
-
-=head1 DESCRIPTION
-
-This module expands and unexpands tabs into spaces, as per the unix expand
-and unexpand programs. Either function should be passed an array of strings
-(newlines may I<not> be included, and should be used to split an incoming
-string into separate elements.) which will be processed and returned.
-
-=head1 AUTHOR
-
-David Muir Sharnoff <muir@idiom.com>
-
-=cut
 
 package Text::Tabs;
 
@@ -46,35 +6,92 @@ require Exporter;
 @ISA = (Exporter);
 @EXPORT = qw(expand unexpand $tabstop);
 
-$tabstop = 8;
+use vars qw($VERSION $tabstop $debug);
+$VERSION = 98.112801;
+
+use strict;
+
+BEGIN	{
+	$tabstop = 8;
+	$debug = 0;
+}
 
 sub expand
 {
-	my @l = @_;
+	my (@l) = @_;
 	for $_ (@l) {
-		1 while s/^([^\t]*)(\t+)/
-			$1 . (" " x 
-				($tabstop * length($2)
-				- (length($1) % $tabstop)))
-			/e;
+		1 while s/(^|\n)([^\t\n]*)(\t+)/
+			$1. $2 . (" " x 
+				($tabstop * length($3)
+				- (length($2) % $tabstop)))
+			/sex;
 	}
 	return @l if wantarray;
-	return @l[0];
+	return $l[0];
 }
 
 sub unexpand
 {
-	my @l = &expand(@_);
+	my (@l) = @_;
 	my @e;
+	my $x;
+	my $line;
+	my @lines;
+	my $lastbit;
 	for $x (@l) {
-		@e = split(/(.{$tabstop})/,$x);
-		for $_ (@e) {
-			s/  +$/\t/;
+		@lines = split("\n", $x, -1);
+		for $line (@lines) {
+			$line = expand($line);
+			@e = split(/(.{$tabstop})/,$line,-1);
+			$lastbit = pop(@e);
+			$lastbit = '' unless defined $lastbit;
+			$lastbit = "\t"
+				if $lastbit eq " "x$tabstop;
+			for $_ (@e) {
+				if ($debug) {
+					my $x = $_;
+					$x =~ s/\t/^I\t/gs;
+					print "sub on '$x'\n";
+				}
+				s/  +$/\t/;
+			}
+			$line = join('',@e, $lastbit);
 		}
-		$x = join('',@e);
+		$x = join("\n", @lines);
 	}
 	return @l if wantarray;
-	return @l[0];
+	return $l[0];
 }
 
 1;
+__END__
+
+
+=head1 NAME
+
+Text::Tabs -- expand and unexpand tabs per the unix expand(1) and unexpand(1)
+
+=head1 SYNOPSIS
+
+    use Text::Tabs;
+
+    $tabstop = 4;
+    @lines_without_tabs = expand(@lines_with_tabs);
+    @lines_with_tabs = unexpand(@lines_without_tabs);
+
+=head1 DESCRIPTION
+
+Text::Tabs does about what the unix utilities expand(1) and unexpand(1)
+do.  Given a line with tabs in it, expand will replace the tabs with
+the appropriate number of spaces.  Given a line with or without tabs in
+it, unexpand will add tabs when it can save bytes by doing so.  Invisible
+compression with plain ascii!
+
+=head1 BUGS
+
+expand doesn't handle newlines very quickly -- do not feed it an
+entire document in one string.  Instead feed it an array of lines.
+
+=head1 AUTHOR
+
+David Muir Sharnoff <muir@idiom.com>