Re: Occur stack

[Daniel Colascione]

On 01/18/2014 10:40 PM, Tom wrote:
> Stefan Monnier <monnier <at> iro.umontreal.ca> writes:
>
> > >       (eval `(let ((dir default-directory)
> > >                    (args command-args))
> > >                (lambda ()
> > >                  (let ((default-directory dir))
> > >                    (grep-find args))))
> > >             t))))
> >
> > Yuck!
>
> This is the first time I used closures, so it may be crude.
>
> Is there a simpler way to write this? First I tried to
> set default-directory in the outer let, but then it had
> apparently no effect on grep-find.

That's because default-directory is marked special and so we don't close 
over its value.

> Hmm, I tried it again and it worked, so I must have had
> some other error when I wrote this.
>
> Is this the simplest way then? Or can it be simplified more?
>
>       (eval `(let ((default-directory default-directory)
>                    (args command-args))
>                (lambda ()
>                  (grep-find args)))
>             t))))

What about this? (Untested.)

(let ((dd-value default-directory))
  (lamda () (let ((default-directory dd-value))
              (grep-find args))))