[mercury-users] The Logic of Mercury

[Richard A. O'Keefe]

Fergus Henderson wrote:
	For example, Lee advocates the use of type systems for higher-order code
	but in that paper he does not make any attempt to say how apply/3 could
	or should be typed.

I note that the call/N family was invented by me as part of the work that
led to the Mycroft/O'Keefe type system reported in AI Journal.  I invented
it because we tried to figure out a straightforward way to type apply/3
and failed.  I believe that the type systems that were worked out for
Flat Concurrent Prolog and for Typed Erlang might lead to a solution, but
they aren't even the same _kind_ of type system as the one Mercury uses.
If anyone has extended type systems like those to handle modes, it would
be interesting to hear about it.

Not altogether coincidentally, call/N turned out to be easier to implement
efficiently than apply/3, although I was never able to talk Quintus into
folding my implementation into the main release.
--------------------------------------------------------------------------
mercury-users mailing list
post:  mercury-users at cs.mu.oz.au
administrative address: owner-mercury-users at cs.mu.oz.au
unsubscribe: Address: mercury-users-request at cs.mu.oz.au Message: unsubscribe
subscribe:   Address: mercury-users-request at cs.mu.oz.au Message: subscribe
--------------------------------------------------------------------------