Re: [Chicken-users] lambda's in a hash table

[Claude Marinier]

On Sat, 5 Apr 2014, Thomas Chust wrote:
> On 2014-04-05 01:54, Claude Marinier wrote:
> > [...]
> > I would like to have the compiler do some of this for me. I probably
> > cannot write a literal hash table but I expected to be able to write a
> > literal association list. I have tried this but it does not work.
> > [...]
> > (define a-list
> >  `(
> >     (dot  . ,(lambda () (display "dot\n")))
> >     (dash . ,(lambda () (display "dash\n")))
> >   ))
> > [...]
>
> Hello,
>
> what you have written down here is not a literal list, but a
> quasiquotation, which is just syntactic sugar that expands to an
> expression dynamically constructing a list.
>
> Nevertheless, the program you posted works just fine as it is. The only
> problem I can see with it is that nothing visible happens because
>
> > [...]
> > (let ((func-dot (hash-table-ref dict 'dot))
> >       (func-dash (hash-table-ref dict 'dash)))
> >   func-dot
> >   func-dash)
> > [...]
>
> doesn't call the two procedures. To actually run the procedures, you
> would have to write something like
>
> (let ((func-dot (hash-table-ref dict 'dot))
>       (func-dash (hash-table-ref dict 'dash)))
>  (func-dot)
>  (func-dash))

That works. Thank you.

I was so close. I think I lost track of the many variations I tried. :-(

--
Claude Marinier