http://qs321.pair.com?node_id=643860


in reply to Re^2: How to swap rows with columns?
in thread How to swap rows with columns?

Good code, but with that very high sigil-to-text ratio, I was scrambling Google to find out what "*_'_" meant. (FWIW, I did not find the answer in Google, or the docs, but figured it out experimentally). (Side note - the single-quote also threw off my editor's perl-highlighter).

Eventually, I decided I would not write code like that, fascinating as it is - it turns out to be just a way to avoid declaring a local variable. It works just as well replacing all instances of that and "$_'_" with "$Column_Index", and becomes a lot more readable ("local *_'_" being replaced by "my $Column_Index" helps by functioning without resorting to "no strict 'refs'").

I'm hoping this node helps other monks who may not have unraveled "_'_".

I'm also curious as to how this would be written in idiomatic perl6.

     "As you get older three things happen. The first is your memory goes, and I can't remember the other two... " - Sir Norman Wisdom

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Re^4: How to swap rows with columns?
by BrowserUk (Pope) on Oct 10, 2007 at 05:24 UTC
      Too much shifting for his taste, surely :)
Re^4: How to swap rows with columns?
by ikegami (Pope) on Oct 10, 2007 at 05:42 UTC

    I'm hoping this node helps other monks who may not have unraveled "_'_".

    You didn't say what it was. ' is Perl4 for ::. It's still supported in Perl5, by it shouldn't be used in new code. This is documented in the second paragraph of perlmod.

    $_::_ is just some arbitrary variable. Despite it's appearance to $_, it's not a special variable.

Re^4: How to swap rows with columns?
by jdporter (Canon) on Oct 10, 2007 at 05:03 UTC

    Yeah, I was just having a bit of fun with that.