Re: pp-eval-expression should use read-expression-history

[Ken Manheimer]

On 10/16/06, Richard Stallman <address@hidden> wrote:
> I made pp-eval-expression use X instead of x,
> and then I made all use of X read the way eval-expression does.
>
> One thing I am not sure of is whether to do the same thing to x.
> allout.el uses x to read objects that are not anything like
> Lisp expressions, so perhaps it is undesirable to use
> read-expression-map for that.
>
>     allout.el:4891:  (interactive "xExposure spec: ")
>     allout.el:4986:  (interactive "xExposure spec: ")
>
> Ken, what do you think?

the thing read certainly should *not* be evaluated.

its structure happens to be similar to a generic lisp expression - an
atom, or a list containing items that, recursively, have this
structure - so reading it as an expression is convenient, and, i
think, appropriate.  evaluating it would be evaluating a list used as
an arbitrary data structure.

(allout.el actually has a widget type, `allout-layout-type', that
declares the exposure spec structure for defcustom.  i believe
`interactive' is not yet able to constrain and prompt for what it
reads according to such a declaration, though, is it?)

--
ken
address@hidden
http://myriadicity.net