[m-rev.] for review: direct parsing of goals

[Peter Wang]

On Mon, 23 Nov 2015 17:09:52 +1100 (AEDT), "Zoltan Somogyi" <zoltan.somogyi at runbox.com> wrote:
> 
> I will add some test cases for the new error messages, but later;
> I plan on making some other modifications first. However, I would
> be grateful if people who work with exceptions would send me,
> or add directly to tests/invalid, examples of real code that had
> syntax errors in try goals.

I think the main errors I have made are:

1. attempting to write a conjunction as the try goal without the outer
   parentheses, i.e.

    ( try [io(!IO)]
	p(!IO),
	q(!IO)
    then
	true
    )

2. forgetting the `then' part

    ( try [io(!IO)]
	p(!IO)
    catch E ->
	true
    )

Peter