Khaaaaan! Change 34230 wasn't right. The tests all passed because I

[p5sagit/p5-mst-13.2.git] / lib / Text / Tabs.pm

diff --git a/lib/Text/Tabs.pm b/lib/Text/Tabs.pm
index 8ca833f..610e870 100644 (file)
--- a/lib/Text/Tabs.pm
+++ b/lib/Text/Tabs.pm
@@ -1,47 +1,136 @@
-#
-# 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;
+
+package Text::Tabs;
 
 require Exporter;
 
 @ISA = (Exporter);
 @EXPORT = qw(expand unexpand $tabstop);
 
-$tabstop = 8;
+use vars qw($VERSION $tabstop $debug);
+$VERSION = 2007.1117;
 
-sub expand
-{
-       my @l = @_;
-       for $_ (@l) {
-               1 while s/^([^\t]*)(\t+)/
-                       $1 . (" " x 
-                               ($tabstop * length($2)
-                               - (length($1) % $tabstop)))
-                       /e;
+use strict;
+
+BEGIN  {
+       $tabstop = 8;
+       $debug = 0;
+}
+
+sub expand {
+       my @l;
+       my $pad;
+       for ( @_ ) {
+               my $s = '';
+               for (split(/^/m, $_, -1)) {
+                       my $offs = 0;
+                       s{\t}{
+                               $pad = $tabstop - (pos() + $offs) % $tabstop;
+                               $offs += $pad - 1;
+                               " " x $pad;
+                       }eg;
+                       $s .= $_;
+               }
+               push(@l, $s);
        }
-       return @l;
+       return @l if wantarray;
+       return $l[0];
 }
 
 sub unexpand
 {
-       my @l = &expand(@_);
+       my (@l) = @_;
        my @e;
+       my $x;
+       my $line;
+       my @lines;
+       my $lastbit;
+       my $ts_as_space = " "x$tabstop;
        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 $ts_as_space;
+                       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;
+       return @l if wantarray;
+       return $l[0];
 }
 
 1;
+__END__
+
+sub expand
+{
+       my (@l) = @_;
+       for $_ (@l) {
+               1 while s/(^|\n)([^\t\n]*)(\t+)/
+                       $1. $2 . (" " x 
+                               ($tabstop * length($3)
+                               - (length($2) % $tabstop)))
+                       /sex;
+       }
+       return @l if wantarray;
+       return $l[0];
+}
+
+
+=head1 NAME
+
+Text::Tabs -- expand and unexpand tabs per the unix expand(1) and unexpand(1)
+
+=head1 SYNOPSIS
+
+  use Text::Tabs;
+
+  $tabstop = 4;  # default = 8
+  @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 (just
+like C<unexpand -a>).  Invisible compression with plain ASCII! 
+
+=head1 EXAMPLE
+
+  #!perl
+  # unexpand -a
+  use Text::Tabs;
+
+  while (<>) {
+    print unexpand $_;
+  }
+
+Instead of the C<expand> comand, use:
+
+  perl -MText::Tabs -n -e 'print expand $_'
+
+Instead of the C<unexpand -a> command, use:
+
+  perl -MText::Tabs -n -e 'print unexpand $_'
+
+=head1 LICENSE
+
+Copyright (C) 1996-2002,2005,2006 David Muir Sharnoff.  
+Copyright (C) 2005 Aristotle Pagaltzis 
+This module may be modified, used, copied, and redistributed at your own risk.
+Publicly redistributed modified versions must use a different name.
+