Re: e and pi

[Stefan Monnier <monnier@IRO.UMontreal.CA>]

>>> This doesn't sound right---it means that people will have to make sure
>>> their function args do not coincide with any defvar, defined anywhere.
>>> It won't just be "e" and "pi" causing problems.  Someone might write
>> 
>>> (defun froob (argv)
>>> (lambda (f) (cons f argv)))
>> 
>>> and have that fail, because "argv" is a defvar defined in startup.el.
>> 
>> Exactly: hence the new warning.

> This sounds fragile.

That's been used for ages in Common-Lisp.  And it's the only reasonable
way to convert Elisp packages from dynamic-scoping to static-scoping
without having to change all `let' to something else (like lexical-let).

> If function argument names are the problem, why not just give them
> static scope, overriding any existing dynamic bindings?  While it's
> idiomatic elisp to use `let' to bind dynamic variables, AFAICT no one
> uses function arguments to do the same.

No, the issue is:

  does (let ((foo bar)) ...) bind `foo' lexically or dynamically?

  
-- Stefan