Re: lexical-binding questions

[Stefan Monnier]

>>>> (setq lexical-binding t)
>>>> (let ((nil 0)) nil)  => 0
>> Anyway, I guess nil and t should be marked as special-variable-p, if for
>> no other reason than because they are pretty damn special.
> The problem also applies to keyword symbols.

Indeed, except it's a lot less likely that people will try to let-bind
a keyword symbol (it happens to me several times a year to choose `t'
for a variable name, only to find it doesn't work, but I never suffered
from that problem with a keyword symbol).

> I was thinking
>       if (!NILP (lexenv) && SYMBOLP (var)
> +         && !SYMBOL_CONSTANT_P (var)
>         && !XSYMBOL (var)->declared_special
>         && NILP (Fmemq (var, Vinternal_interpreter_environment)))
>       /* Lexically bind VAR by adding it to the lexenv alist.  */
>       lexenv = Fcons (Fcons (var, tem), lexenv);

It would be more efficient to set declared_special on keyword symbols.


        Stefan