[m-rev.] for review: better error messages for bad inst and mode names

[Zoltan Somogyi]

On Tue, 26 Apr 2016 09:18:37 +1000 (AEST), Julien Fischer <jfischer at opturion.com> wrote:
> > +            LHSTerm = term.functor(_, _, LHSContext),
> > +            LHSTermStr = describe_error_term(VarSet, LHSTerm),
> > +            LHSPieces = [words("Error: a non-variable inst such as"),
> 
> Add some commas there.
> 
>      Error: a non-variable inst, such as `foo', may not be the

I think that would be the right thing to do IF `foo' was an example.
In this case, it is NOT a merely example: it is the term that the
error message is complaining about. I think putting commas around it
would make that a bit harder to see.

Do you think wording these messages like this:

   `foo' is a non-variable inst, and as much may not ...

would be an improvement?

I am following all your other suggestions. Thanks for the review.

Zoltan,