Re: unused local variables

[Stefan Monnier <monnier@iro.umontreal.ca>]

> Are you saying that in

>  (defun test ()
>    (if my-dynamic-var
>        "correct"
>      "erroneous"))

>  (let ((my-dynamic-var t))
>    (test))

> you would force my-dynamic-var to be `defvar'ed to avoid a warning in the let?

Yes.  And that's good.  E.g. if you want to compile this file with the
lexical-scoping version of Emacs that Miles has been working on, this
is indispensable.

BTW, in the above example, the byte-compiler already complains in the
`test' function, so it's not like it's going to make that big
a difference.

Also dynamic scoping is sufficiently odd and rarely used that it deserve
special mention in the code.  It's pretty common to mark it with
a comment.  And code is always better than a comment since it tends to
bitrot a bit less quickly.


        Stefan


PS: Another "unused var" warning which we should add (I don't have it
    in my lock hack yet, tho) is the one that notices when a `defvar'
    declares a variable which is not used in the file.