[mercury-users] Re: coloured petri nets

[Peter Ross]

On Thu, Sep 06, 2001 at 02:56:49PM +0200, Peter Ross wrote:
> I think I can implement things the way I want to if I can implement the
> following functions
> 
> :- type petri
> 	--->    ?.
> :- type ref(T)
> 	--->    ?.
> 
> :- func get_place(petri, ref(place(T)) = place(T).
> 
> In otherwords given some type petri and a reference to a place(T) in the
> type petri, get me back the place(T).
> 
> Similary I will need
> 
> :- pred insert_place(petri::in, place(T)::in,
> 		ref(place(T))::out, petri::out) is det.
> 
> :- func set_place(ref(place(T)), place(T), petri) = petri.
> 
Which I guess would be the following.

:- module petri2.

:- interface.

:- type petri.

:- type ref(T).

:- type place(T) --->   p(T).

:- pred insert_place(place(T)::in, ref(place(T))::out,
                petri::in, petri::out) is det.

:- func get_place(petri, ref(place(T))) = place(T).

:- implementation.

:- import_module int, map, std_util.

:- type ref(T)
        ---> ref(int).

:- type petri
        --->    petri(
                        id      :: int,
                        map     :: map(int, univ)
                ).

insert_place(Place, ref(Id), petri(Id, Map0), petri(Id + 1, Map)) :-
        map__det_insert(Map0, Id, univ(Place), Map).

get_place(petri(_NextId, Map), ref(Id)) = Place :-
        map__lookup(Map, Id, UnivPlace),
        det_univ_to_type(UnivPlace, Place).
--------------------------------------------------------------------------
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
--------------------------------------------------------------------------