Re^3: 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

Comment on Re^3: How to swap rows with columns?

Replies are listed 'Best First'.
Re^4: How to swap rows with columns? by BrowserUk (Pope) on Oct 10, 2007 at 05:24 UTC
Why not just do away with the local var completely: `@a = ( [1..3],['a'..'c'],['x'..'z']);; @a = map{ [ map{ shift @$_ } @a ] } 1 .. @{ $a[0] };; print pp @a;; ([1, "a", "x"], [2, "b", "y"], [3, "c", "z"])` [download] Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error. "Science is about questioning the status quo. Questioning authority". In the absence of evidence, opinion is indistinguishable from prejudice. "Too many [] have been sedated by an oppressive environment of political correctness and risk aversion."	[reply] [d/l]
Re^5: How to swap rows with columns? by ikegami (Pope) on Oct 10, 2007 at 05:48 UTC
Too much shifting for his taste, surely :)	[reply]
Re^4: How to swap rows with columns? by ikegami (Pope) on Oct 10, 2007 at 05:42 UTC
I'm hoping this node helps other monks who may not have unraveled "_'_". You didn't say what it was. `'` is Perl4 for `::`. It's still supported in Perl5, by it shouldn't be used in new code. This is documented in the second paragraph of perlmod. `$_::_` is just some arbitrary variable. Despite it's appearance to `$_`, it's not a special variable.	[reply] [d/l] [select]
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.	[reply]


Just another Perl shrine
	PerlMonks