Re: Code for cond*

[JD Smith <jdtsmith@gmail.com>]

> On Jan 25, 2024, at 11:12 AM, Alfred M. Szmidt <ams@gnu.org> wrote:
> 
> The above "idiom" is much easier to understand since it just uses well
> known Lisp behaviour than modifying cond even if it is really ugly
> ... the feature is a nice addition, but is it worth it?

I tend to agree that wrapping the entire cond in let is not too bad.  It increases indentation depth for a very common need, but has the advantage that you “look up to parent forms for the bindings” which I think is natural for most elisp developers.

There is however no equivalent simple idiom for cond-let — a proposed member of the if-let/when-let family.  Unless, that is, you consider this simple:

(catch 'cond-let
 (when simple0 (throw 'cond-let body0))
 (when-let (bindings1) (throw 'cond-let body1))
 (when-let (bindings2) (throw 'cond-let body2))
 (when-let (bindings3) (throw 'cond-let body3))
 (throw 'cond-let fallthrough-body))