RE: Predicate for true lists

[Drew Adams]

> > > > IIRC, the main motivation for adding this function was
> > > > to provide a predicate for testing properness.
> > >
> > > Then I'd prefer calling the function proper-list-p (and returning the
> > > list length when it's a proper list) than the other way around.
> >
> > Then discoverability of the use for length is reduced.
> 
> Not if we state in the doc string that the value returned
> for proper lists is the list length.

I disagree, but it's not the end of the world if you
don't provide the alias.

I was referring to _discoverability_ by looking for a
function with a name that suggests "length".  (And vice
versa, if you are looking for a predicate and the only
name that exists says "length".)

Help functions that work off of the function name will
not be very helpful in finding the other function, if
only one name is provided.  This function has two quite
different use cases, and it would help to have two
corresponding aliases.