reverse interpolation

gleeco has asked for the wisdom of the Perl Monks concerning the following question:

Replies are listed 'Best First'.
Re: reverse interpolation by parv (Parson) on Sep 17, 2008 at 06:31 UTC
Is that a trick question? By using a look up table aka hash... `my %map = ( "\t" => '\t' ); my $y = "\t"; print $map{ $y };` [download] See also Re^3: Generating characters (0 to 255). After skimming referenced post ... Removed unnecessary `chr ord` functions.	[reply] [d/l] [select]
Re^2: reverse interpolation by Erez (Priest) on Sep 17, 2008 at 07:09 UTC
Is that a trick question? Seeing as the title is "reverse interpolation", the OP probably wondered whether there is some way to have perl magically understand that if $foo = "bar", then `print "bar"` could actually print '$foo'... Seeing as it isn't, a more sensible approach emerged. Stop saying 'script'. Stop saying 'line-noise'. We have nothing to lose but our metaphors.	[reply] [d/l]
Re^2: reverse interpolation by gleeco (Novice) on Sep 17, 2008 at 06:53 UTC
so obvious i'm obviously not... but why the trouble with chr ord when it works without? thanks!	[reply]
Re^3: reverse interpolation by parv (Parson) on Sep 17, 2008 at 07:00 UTC
You missed the update by a few seconds! You are right that chr ord chain was unnecessary (I started by finding the number to represent a tab, which I changed to use "ord", which changed to just the interpolated string). Obviously, I should have just started & ended with plain tab ... as you wrote "so obvious i'm obviously not". `:}`	[reply]
Re: reverse interpolation by moritz (Cardinal) on Sep 17, 2008 at 07:38 UTC
You can use Data::Dumper and set `$Data::Dumper::Useqq = 1` prior to dumping. No need to re-invent the wheel. (If that `$VAR1 =` disturbs you can set the `Terse` flag as well).	[reply] [d/l] [select]
Re: reverse interpolation by salva (Canon) on Sep 17, 2008 at 08:22 UTC
`use Scalar::Quote qw(quote); $x = "\t"; print quote($x), "\n";` [download]	[reply] [d/l]
Re: reverse interpolation by repellent (Priest) on Sep 17, 2008 at 07:17 UTC
Are you sure you don't want to print `'\cI'` instead of `'\t'`?	[reply] [d/l] [select]
Re: reverse interpolation by Anonymous Monk on Sep 17, 2008 at 07:10 UTC
You could also do a replace: `$y = $x; $y =~ s/\t/\\t/g;` [download]	[reply] [d/l]
Re: reverse interpolation by Anonymous Monk on Sep 19, 2008 at 02:35 UTC
http://perldoc.perl.org/functions/quotemeta.html `$x = "\t"; print quotemeta $x;` [download]	[reply] [d/l]
Re^2: reverse interpolation by ikegami (Patriarch) on Sep 19, 2008 at 06:39 UTC
No, that doesn't return `"\\t"` as requested. It returns `"\\\t"`	[reply] [d/l] [select]