Re^5: passing subroutine references

Global? There ain't any global sir.

Global to all calls to hanoi. External? Non-local? Yet highly coupled.

And _hanoi(@_); would work just as well

That's what I said.

while your tricks with local are unavoidable.

How is localising a var "a trick"? Dealing with package vars is a necessity in Perl, and the first thing you need to know is how to localise them.

It is avoidable, but it's messy and requires a trick to avoid a memory leak.

my $_hanoi;         # \ Messy line break
$_hanoi = sub {     # /
   ...
   $_hanoi->(...);  # Relatively messy syntax
   ...
};
$_hanoi->(...);
undef $_hanoi;      # Messy hack to avoid mem leak.
[download]

Using local actually cleans up a whole of mess.

Besides the problem is not the local itself, but the typeglob handling.

"The typeglob handling" makes "setting a typeglob" sound falsely ominous. It's a manufactured problem.

What debugging complexities are you speaking of?

The removal of a stack frame creates lying stack traces, not just to users but to debugging tools.

Comment on Re^5: passing subroutine references Select or Download Code

Replies are listed 'Best First'.
Re^6: passing subroutine references by Jenda (Abbot) on Sep 20, 2009 at 21:51 UTC
It's static and lexical to two subroutines. And yes, localizing a var is a trick. Something that confuses most newcomers to Perl. Localizing a whole typeglob so that you could call the newly created closure as if it was an ordinary subroutine doubly so. If you insist on using local(), localize the $move_disk and define the _hanoi() as an ordinary subroutine accessing the package variable $move_disk. BTW, what was the last time you actually generated a stack trace? Jenda Enoch was right! Enjoy the last years of Rome.	[reply]
Re^7: passing subroutine references by ikegami (Patriarch) on Sep 21, 2009 at 03:02 UTC
BTW, what was the last time you actually generated a stack trace? I used `confess` and code analysers on my previous workday. define the _hanoi() as an ordinary subroutine accessing the package variable $move_disk. Yeah, you could make `_hanoi` public, but it doesn't buy you anything to do so.	[reply] [d/l] [select]
Re^7: passing subroutine references by ikegami (Patriarch) on Sep 21, 2009 at 03:00 UTC
<bockquote> BTW, what was the last time you actually generated a stack trace? I used `confess` and code analysers on my previous workday. define the _hanoi() as an ordinary subroutine accessing the package variable $move_disk. Yeah, you could make `_hanoi` public, but it doesn't buy you anything to do so.	[reply] [d/l] [select]