Re: Best practices for warnings about wrong context

[dsheroh]

I can't imagine how (b) could be a "yes". Different callbacks are naturally used in different contexts. Sometimes it makes sense for a callback to return a value, other times it doesn't. And sometimes (like Catalyst), the framework is generic enough that the framework designer can't know in advance whether a return value is expected from a given callback or not.

All that aside, I lean towards "no" on (a) regardless. The entire concept of issuing a warning for calling a sub in the wrong context rubs me the wrong way on a rather deep level. I can't identify exactly why, but it's probably connected to the fact that "doing something that doesn't make sense to the module's author" does not necessarily imply "doing something wrong".

[mr_mischief]

Maybe I've taken references to a few different subs and passed them around, and then at some point call whichever one has been passed? Maybe some other sub returns a scalar, a hashref, a list, or whatever. What happens if I want to use the sub that refuses to be used in list context or scalar context?

Well I can wrap it in another sub, maybe an anonymous sub, which doesn't seem like a heart-rending, mind-warping workaround. Should wrapping it be necessary? Who's to say, really? If someone wants to return any kind of user data or status information, it would require the wrapper anyway since the author didn't return anything from the original sub. One might as well have the wrapper call it in void context then return whatever you like.