Re^3: on the fly reference to subroutine output

in reply to Re^2: on the fly reference to subroutine output
in thread 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

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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]

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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]

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