Re: Lexical binding

[Juanma Barranquero]

On Sun, Apr 3, 2011 at 14:05, Christian Ohler <address@hidden> wrote:

> In loop destructuring, you can use nil for fields that you want to ignore:
>
>     (loop for (nil width . nil) in bs-attributes-list
>           if (numberp width) sum width)

Yes, but it is less informative.

> If you want to keep the ignored fields named, you could do something like
>
>     (loop for (name width . rest) in bs-attributes-list
>           do (progn name rest) ; ignore
>           if (numberp width) sum width)

And this is just ugly.

Anyway, the point is that (elisp)11.9.5.1 "Converting a package to use
lexical scoping" says:

     To silence byte-compiler warnings about unused variables, just use a
  variable name that start with an underscore, which the byte-compiler
  interpret as an indication that this is a variable known not to be used.

but this exception is quite less useful if assignments produce the
"variable `_x' not left unused" warning.

Thanks,

    Juanma