[alexandria-devel] if-let*

[Nikodemus Siivola]

On 24 November 2012 18:59, Marco Baringer <mb at bese.it> wrote:

>   i recently needed (or just decided that i wanted it) a version of
>   if-let with sequential binding. The bindings form is as with if-let,
>   however to ensure that only the 'true' bindings are seen in the else
>   form (and i'm not convinced this is worth it) the else form is
>   repeated multiple times (once per binding) in the macro's expansion.
>
>   the docstring should explain how it works (and if not i'll fix the
>   docstring).
>
>   and, since it made sense to me at the time, when-let and when-let* are
>   implemented in terms of if-let and if-let* (instead of repeating the
>   binding expansion and and code).

It seems very strange to me that you leave variables unbound in the
ELSE branch -- so you can only refer to the first one.

Either all should be bound in the ELSE branch or non should be.

Otherwise no complaints -- and would be happy to merge. (Or if there's
a rationale for the unboundness I'm happy to hear. It just isn't
obvious to me.)

Cheers,

 -- Nikodemus