[MLton] Ad-hoc infix identifiers, Printf, and libraries
Thu, 14 Jul 2005 19:27:46 +0200
Vesa Karvonen wrote:
> I'm not exactly sure what you have in mind.
Consider library A defining operators P, Q, R, and library B defining
operators U, V, W. I can only specify the relative precedences of
operators within one of the libraries. I cannot specify any
inter-library precedences without creating a dependency between the
libraries. Still such precedences might be useful.
> One could, for example, introduce virtual or place-holder operators for
> making it easier to combine groups of precedences. Basically, a library
> would introduce fixity declarations that are only used for the purpose of
> allowing users to declare precedences relative to the actual operators
> in the library robustly and conveniently.
OK, but that would either restrict inter-library precedences to a set of
dummy operators pre-defined globally, or require intervention on part of
the user of the libraries. Both does not make it significantly more
attractive than what you have with absolute numeric precedences. What if
I want P<U<V<Q<W<R? If we really intend to make non-trivial use of infix
(which seems the whole point of the discussion) that may not be an
I guess my point is that your proposal, while looking neat, still does
not provide a general solution, it may even be less convenient in cases,
and hence may not be worth the complication. I have people seen
suggesting real-valued precedences - that seems more powerful, but also
> But this is probably getting off-topic...
Andreas Rossberg, firstname.lastname@example.org
Let's get rid of those possible thingies! -- TB