revising ev, was: problem with "concatting variables"

On 2013-09-26, Raymond Toy <toy.raymond at gmail.com> wrote:

> We should probably change that message.  I think that's easy
> enough.  Do we still want to spam the use with the actual Lisp error?
> I think that's useful information.

Yes, we should keep the Lisp error. We can change the wording, I guess,
to "internal error" instead of "Lisp error".

> Any reason not to extend length to work with strings?

Well, there does exist 'slength' already (although that doesn't preclude
a 'length' which acts on strings). More fundamentally, 'length' returns
the number of arguments in an (nonatomic) expression, which for a list
is the length of the list, and so length of string is something else.
I'm generally wary of combining different kinds of functions under the
same name. Not 100% opposed, but leaning that way.

best

Robert Dodier