Re: master b72f885: Make dlet work like let, not let*

[Tassilo Horn <tsdh@gnu.org>]

Jean Louis <bugs@gnu.support> writes:

> I am user and I do not expect it to work as `let' because `dlet' is
> supposed to make temporarily global variables. Now it doesn't work:
>
> (dlet ((wrs::variables (make-hash-table :test 'equal))
>        (wrs::_ (puthash "areas_name" "Hyperscope" wrs::variables)))
>   )
>
> error: let: Symbol’s value as variable is void: wrs::variables
>
> That is IMHO wrong, as it is supposed to bind variables
> dynamically:

Being able to refer to variables earlier in the same binding form has
nothing do with dynamic binding.  `let' and `dlet' don't support that,
`let*' does, and as Mattias said, there could be a `dlet*' if someone
needs it.

What dlet allows you is to bind variables dynamically which are no
special variable (are not declared with defvar).  For example:

--8<---------------cut here---------------start------------->8---
(defun foo ()
  some-var)

(foo) ;; Lisp error: (void-variable some-var)

(dlet ((some-var 17))
  (foo)) ;=> 17
--8<---------------cut here---------------end--------------->8---

But instead of dlet you could just as well defvar some-var and use a
normal `let' instead.

Why can't you defvar wrs::variables?  Or maybe it already is?  In that
case, you could just replace `dlet' with `let*'.

Bye,
Tassilo