Re^3: on the fly reference to subroutine output

The incorrect assumption here is that sub1 is returning an array.

In perl5, subs can return scalars or lists. Since it's not returning a (scalar) reference to an array, the only option is to store the list into a (possibly anonymous) array and pass a reference into sub2

tjd

Comment on Re^3: on the fly reference to subroutine output

Replies are listed 'Best First'.
Re^4: on the fly reference to subroutine output by thirdm (Sexton) on Mar 05, 2013 at 05:28 UTC
Ah, I'm always forgetting this. But underneath, is there a chance at some kind of return value optimization? Say if you have... `sub1 { ... return @a; } $r = [sub1];` [download] Even if it's officially turning the values of @a into a list en route to copying them into the array that the brackets create a reference to, could perl not notice @a is no longer needed otherwise and instead simply make `[sub1]` be `\@a` behind the scenes? It would be neat if you could write sub1 that way instead of making it return \@a even if you anticipated the copy to be expensive.	[reply] [d/l] [select]

Replies are listed 'Best First'.

Re^4: on the fly reference to subroutine output
by thirdm (Sexton) on Mar 05, 2013 at 05:28 UTC

Ah, I'm always forgetting this.

But underneath, is there a chance at some kind of return value optimization? Say if you have...

sub1 {
...
   return @a;
}

$r = [sub1];
[download]

[sub1]

\@a

[reply]
[d/l]
[select]