|P is for Practical|
Forcing list context of passed parametersby papidave (Monk)
|on Sep 28, 2007 at 21:16 UTC||Need Help??|
papidave has asked for the
wisdom of the Perl Monks concerning the following question:
As-of sidhekin's note on "Don't use it if you don't mean it", the selected resolution of omitting the prototype from foo -- which I was actually doing to make things work -- is now established as the de facto standard. Following C standards for Perl is clearly a dangerous path to follow.
If the lecture Gratuitous use of Perl Prototypes hadn't ended with a self-satisfied snigger, I might have even ++'ed it.
Correction "4" => "four", typo cut/paste from an earlier version of foo.pl, where I had passed it through the gotse operator as an attempt at listifying it.
-- snip --
Here's one that had me scratching my head for some time. Background follows:
The problem that I have with this is that I like to use prototypes, as a form of self-documenting code. I even use them in object methods, where they don't get enforced, because I want the reader to know what arguments I expect to receive. Ideally, what I want is to list-ify the qw() results, so they'll be passed through foo() intact.
My copy of the Camel asserts (vol 3, p.778):
There's no "list" function corresponding to scalar since, in practice, one never needs to force evaluation in a list context.
I already have multiple potential workarounds -- changing or eliminating the prototype, isolating "one" from the qw() list, etc. -- but it just doesn't seem "right" to have to do this. I see that Perl6 (http://dev.perl.org/perl6/rfc/175.html) may have a "list" keyword that would solve this cleanly.
Does this mean that I'm really running into a pathological edge case in Perl5, or am I just being boneheaded in my approach to the problem? Is there some (reasonably elegant) way to list-ify the args before they get passed to foo()?