[MLton] Implementing warnExnMatch

[Vesa Karvonen]

Quoting Stephen Weeks <sweeks@sweeks.com>:
> Sorry for joining the party late, but I find the current specification
> and implementation of warnExnMatch a bit ad-hoc.  Let me propose a
> different approach.  What "warnExnMatch false" should mean is to
> eliminate all nonexhaustive match warnings that arise solely from
> unmatched exceptions. [...]

I agree. This is much better. I guess the main reason I didn't try going
that far is mainly the fact that it required changes beyond elaborate.
Well, if you had pushed me earlier, I might have tried it... :)

What is the policy for documenting features that have not yet appeared
in a public release? Should warnExnMatch already be mentioned on the Wiki
(http://mlton.org/MLBasisAnnotations)?

A brief note could look something like this:

<--->
{{{warnExnMatch {true|false} }}}
  Report nonexhaustive matches that arise solely from unmatched exceptions.
  (Since 20050727.)
<--->

-Vesa Karvonen