Re: [Sml-implementers] Subject: Standard ML

[Stephen W. <sw...@in...>]

Andreas:
> During compiling this I also made a bunch of contrived test files to
> see how implementations cope with some of the more obscure details of
> the
> Definition (i.e. those that are tedious to implement or are pretty
> counter-intuitive, as noted in the list). Here is a table of the results
> (I hope Netscape does not gargle it):
...

Three of your test cases tickled another obscure part of the
Definition (to me anyway), and I suspect it was unintentional on your
part.  The tests "asterisk", "semicolon", and "typespec" contained the
'\r' character (ascii decimal 13).  Quoting from the Definition:
  
Section 2.5:
	Comments and formatting characters separate items (except with
	string constants; see Section 2.2) and are otherwise ignored.
Section 2.2:
	The formatting characters are a subset of the non-printable
	characters including at least space, tab, newline, formfeed.

Since carriage return is not required to be a formatting character, I
believe that it is acceptable for an implementation to reject programs
containing carriage returns, although it is also allowable to accept
them.  At present, MLton rejects them.

I would be happy for clarification.


BTW, as an implementor, I really appreciate having examples like this
to clarify things.   Thanks for making them.  I think that a set of
well-constructed examples is as essential as the Definition in making
different implementations consistent.  I would like to see more cases
like these, and for all proposed language extensions to come along with
such a set of test cases.