Re: need for 'dynamical-let'?

[Stephen Leake <stephen_leake@stephe-leake.org>]

Stephen Leake <stephen_leake@stephe-leake.org> writes:

> I'm switching on lexical-binding in some files.
>
> In several cases, the byte compiler is complaining:
>
> xgit.el:993:30:Error: add-to-list cannot use lexical var `branch-list'
>
> So I have to change code like this:
>
> (let (branch-list
>       ...)
>    (add-to-list branch-list (substring branch-entry 2) t)
>
>
> to:
>
> (defvar dvc-branch-list);; add-to-list can't use lexical var
> (let (
>       ...)
>    (add-to-list 'dvc-branch-list (substring branch-entry 2) t)
>
>
> This pollutes the global name space, and disguises the local nature of
> 'branch-list'.
>
> Can we define a macro 'dynamical-let' that would implement this
> pattern, but with hidden variables?


Also, how do I know which functions I write also can't use lexical
variables? Using 'symbol-value' would be one clue, apparently. I hope
the byte-compiler will complain?

-- 
-- Stephe