[m-rev.] support `mmake install' in extras directory

[Fergus Henderson]

On 07-Mar-2002, Tyson Dowd <trd at cs.mu.OZ.AU> wrote:
> On 06-Mar-2002, Fergus Henderson <fjh at cs.mu.OZ.AU> wrote:
> > extras/curs/curs.m:
> > 	Add `promise_pure' declarations for all pure procedures.
> > 	XXX Should this be needed?  These predicates all take
> > 	io__state arguments.
> 
> I'm not sure what you mean here.
> 
> The fact that a particular predicate takes IO state arguments
> doesn't necessarily mean it is pure.
> 
> There may be another predicate in the same module (or a different
> module) that does not take IO states, which does something impure
> and modifies the declarative semantics of the first:
> 
> e.g. consider:
> :- pragma foreign_proc("C", rows_cols(Rows::out, Cols::out, IO0::di,
> 		IO::uo),
> 
> :- pragma foreign_proc("C", move(Row::in, Col::in),
> 
> rows_cols doesn't seem very pure in this case.  It should be unaffected
> by the invocation of move (they don't share the IO state, do they),
> but it's not.

Hmph.  OK, you've convinced me.

-- 
Fergus Henderson <fjh at cs.mu.oz.au>  |  "I have always known that the pursuit
The University of Melbourne         |  of excellence is a lethal habit"
WWW: <http://www.cs.mu.oz.au/~fjh>  |     -- the last words of T. S. Garp.
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