1 files changed, 47 insertions, 0 deletions
diff --git a/lib/Text/Tabs.pm b/lib/Text/Tabs.pm
new file mode 100644
index 0000000000..8ca833f8e8
--- /dev/null
+++ b/lib/Text/Tabs.pm
@@ -0,0 +1,47 @@
+#
+# 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>
+# 
+
+package Tabs;
+
+require Exporter;
+
+@ISA = (Exporter);
+@EXPORT = qw(expand unexpand $tabstop);
+
+$tabstop = 8;
+
+sub expand
+{
+	my @l = @_;
+	for $_ (@l) {
+		1 while s/^([^\t]*)(\t+)/
+			$1 . (" " x 
+				($tabstop * length($2)
+				- (length($1) % $tabstop)))
+			/e;
+	}
+	return @l;
+}
+
+sub unexpand
+{
+	my @l = &expand(@_);
+	my @e;
+	for $x (@l) {
+		@e = split(/(.{$tabstop})/,$x);
+		for $_ (@e) {
+			s/  +$/\t/;
+		}
+		$x = join('',@e);
+	}
+	return @l;
+}
+
+1;