[pro] Lisp 2's and function values.

[Pascal Costanza]

On 26 May 2011, at 02:07, Matthew D. Swank wrote:

> On 05/25/2011 04:05 PM, Alessio Stalla wrote:
>> It's not about syntax, it's about a missing feature: the ability to
>> bind a symbol's function "cell" to a value that's not known at compile
>> time. 
> I've used this for pedagogical purposes:
> (defmacro f-let ((&rest bindings) &body body)
>  (let* ((let-bindings (mapcar (lambda (binding)
>                        (list (gensym) (cadr binding)))
>                      bindings))
>         (flet-bindings (mapcar (lambda (binding let-binding)
>                                 `(,(car binding) (&rest args)
>                                    (apply ,(car let-binding) args)))
>                               bindings
>                               let-bindings)))
>    `(let ,let-bindings
>       (flet ,flet-bindings
>         , at body))))
> 
> but it hardly solves the problem.

Why does it not solve the problem? Your definition shows that adding such a feature is just a matter of defining a macro, so it's more or less at the same level of adding a looping construct - it doesn't increase the expressiveness of the language (in the sense of Felleisen's macro-expressiveness).

So, what "problem" do you have in mind here?


Pascal

--
Pascal Costanza
The views expressed in this email are my own, and not those of my employer.