Re: Confused Contexts and wantarray

When it's called in scalar context, I want it to return either a single object if there's only one, or the array reference if there's more than one

In my opinion, that's the wrong thing to do. wantarray lets you take context from what the caller wants. It amounts to an extra service by the sub. Changing the return type based on some property of the data is a whole different thing. It requires the caller to either test or already know what it gets back from the call. I consider that a design error.

The link data should be designed to always be the same kind of thing, in this case an array reference. That will save a lot of trouble.

After Compline,
Zaxo

Comment on Re: Confused Contexts and wantarray

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Re^2: Confused Contexts and wantarray by Smylers (Pilgrim) on Jan 18, 2005 at 09:45 UTC
return either a single object if there's only one, or the array reference if there's more than one In my opinion, that's the wrong thing to do. ... Changing the return type based on some property of the data is a whole different thing. It requires the caller to either test or already know what it gets back from the call. I consider that a design error. I completely agree with that. It's one of the things that's so annoying about `CGI::Lite` (for which I'm the current maintainer); having to test whether you've got an array-ref and then deal with it if you have is more effort than just always getting an array-ref. The link data should be designed to always be the same kind of thing, in this case an array reference. I'm not convinced by that, though. I like what `CGI` does in scalar context: it presumes that you used scalar context cos you're only expecting one item, so it just gives you one item, the first (or only) item in the list. I think that approach may also make sense here: `return ref $link ? (wantarray ? @$link : $link->[0]) : $link;` [download] Smylers	[reply] [d/l] [select]

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Re^2: Confused Contexts and wantarray
by Smylers (Pilgrim) on Jan 18, 2005 at 09:45 UTC

return either a single object if there's only one, or the array reference if there's more than one
In my opinion, that's the wrong thing to do. ... Changing the return type based on some property of the data is a whole different thing. It requires the caller to either test or already know what it gets back from the call. I consider that a design error.

I completely agree with that. It's one of the things that's so annoying about CGI::Lite (for which I'm the current maintainer); having to test whether you've got an array-ref and then deal with it if you have is more effort than just always getting an array-ref.

The link data should be designed to always be the same kind of thing, in this case an array reference.

I'm not convinced by that, though. I like what CGI does in scalar context: it presumes that you used scalar context cos you're only expecting one item, so it just gives you one item, the first (or only) item in the list. I think that approach may also make sense here:

return ref $link ? (wantarray ? @$link : $link->[0]) : $link;
[download]

Smylers

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