[m-dev.] semantics with any insts

[Ralph Becket]

Ralph Becket, Wednesday, 29 March 2006:
> An idea just occurred to me: 
> 
> For a procedure whose headvars are all ground or free on exit:
> - operational failure is definite semantic failure
> - operational success is definite semantic success
> 
> For a procedure whose headvars may have inst any on exit:
> - operational failure is definite semantic failure
> - operational success is *possible* semantic success
> 
> It should be an error for a procedure of the first kind to have local
> inst any vars without enclosing that code in a promise_consistent scope.

Actually, the promise_consistent scope should also include any code
manipulating head vars that have inst any on entry to the procedure.

-- Ralph
--------------------------------------------------------------------------
mercury-developers mailing list
Post messages to:       mercury-developers at cs.mu.oz.au
Administrative Queries: owner-mercury-developers at cs.mu.oz.au
Subscriptions:          mercury-developers-request at cs.mu.oz.au
--------------------------------------------------------------------------