%-----------------------------------------------------------------------------%

:- module rdfStore.
:- interface.

:- type rdfStore__open(OpenStore).
:- inst rdfStore.inst_open(S) ---> rdfStore__open(S).

:- type rdfStore__transact(TransactStore).
:- inst rdfStore.inst_transact(S) ---> rdfStore__transact(S).

:- type state_of_store(Store) --->
            astore(Store)
        ;   open(rdfStore.open(Store))
        ;   trans(rdfStore.open(rdfStore.transact(Store)))
        .

:- inst readable    ---> open(ground); trans(ground).

% XXX when these are not in the interface, then the output variable of
%     get_od_read has unqualified functors in its inst.
%     When these are in the interface then the functors are correctly
%     module qualified.
%
% :- type rdfStore__open(OpenStore)
%         --->    rdfStore__open(OpenStore).
% 
% :- type rdfStore__transact(TransactStore)
%         --->    rdfStore__transact(TransactStore).

:- func inst_store_open(Store::in(I)) =
    (rdfStore__open(Store)::out(rdfStore.inst_open(I))) is det.
:- func inst_open_store(rdfStore__open(Store)::in(rdfStore.inst_open(I))) =
    (Store::out(I)) is det.

%-----------------------------------------------------------------------------%
%-----------------------------------------------------------------------------%

:- implementation.

:- type rdfStore__open(OpenStore)
        --->    rdfStore__open(OpenStore).

:- type rdfStore__transact(TransactStore)
        --->    rdfStore__transact(TransactStore).

inst_store_open(Store) = (rdfStore__open(Store)).
inst_open_store(rdfStore__open(Store)) = (Store).

%-----------------------------------------------------------------------------%
% vim: ft=mercury ts=8 sw=4 et wm=0 tw=0