Re: if-let and when-let: parallel or sequential

[Bozhidar Batsov]

On August 10, 2014 at 6:23:25 PM, Stefan Monnier (address@hidden) wrote:

> I noticed that the new `if-let' and `when-let' in trunk's subr-x create
> their bindings sequentially (like `let*' rather than `let'). Would there
> be any interest in renaming these to `if-let*' and `when-let*', and
> adding parallel-binding versions under the current names?

I have a hard time imagining a situation where the "parallel" version
would be useful.


Stefan

if-let and when-let don’t make much sense with more than one binding form. Other lisps (like Clojure) would raise

an exception if you try to bind more than a single form.

;; good

(if-let ((x (something)))

    …)

;; error

(if-let ((x (something))

           (y (something-else)))

    …)

I’d suggest we do the same.