I have this for array :
ary1d_new(Size,Sym,ArySym,Ary) :-
functor(Ary,ArySym,Size),
forall(arg(X,Ary,_), nb_setarg(X,Ary,Sym)).
ary1d_get(Pos,Ary,Val) :- arg(Pos,Ary,Val).
ary1d_set(Pos,Ary,Val) :- nb_setarg(Pos,Ary,Val).
trying to turn it to logtalk object, but is not happening for me
:- object(array, instantiates(array)).
:- initialization(init).
:- private(init/0).
:- public(ary/1).
:- dynamic(ary/1).
ary(_).
:- public([new1d/2, set1d/2, get1d/2]).
new1d(Size,Sym) :-
functor(Ary,ary,Size),
forall(arg(X,Ary,_), nb_setarg(X,Ary,Sym)),writeln(Ary).
get1d(Pos,Val) :- arg(Pos,::ary,Val).
set1d(Pos,Val) :- nb_setarg(Pos,::ary,Val).
init :- true.
:- end_object.
:- object(g, instantiates(array)).
:- end_object.
?- g::new1d(5,0).
ary(0,0,0,0,0)
true.
?- g::set1d(2,7).
false.
?- g::get1d(2,D).
false.
what is the correct way ? functor vs ::ary is confusing me
came up with this for Obj attributes out of the array storage :
:- public(test/2).
test(Size, Value) :- test(Size,Value,i(Size)).
:- public(test/3).
test(Size, Value, Info) :-
functor(A, s, Size),
forall(
arg(Arg, A, _),
nb_setarg(Arg, A, Value)
),
_Array_ = a(Info,A).
?- ary(A)::test(5,0).
A = a(i(5), s(0, 0, 0, 0, 0)).
CodePudding user response:
Note that you can only call the nb_setarg/3
on compound term arguments. A possible alternative could be to use a parametric object:
:- object(array(_Array_)).
:- public(new/2).
new(Size, Value) :-
functor(_Array_, a, Size),
forall(
arg(Arg, _Array_, _),
nb_setarg(Arg, _Array_, Value)
).
:- public(get/2).
get(Arg, Value) :-
arg(Arg, _Array_, Value).
:- public(set/2).
set(Arg, Value) :-
nb_setarg(Arg, _Array_, Value).
:- end_object.
A sample query would be:
?- {arrays}.
% [ .../arrays.lgt loaded ]
% (0 warnings)
true.
?- array(Array)::(new(5,0), set(2, 7), get(2, Value)).
Array = a(0, 7, 0, 0, 0),
Value = 7.
Note that the _Array_
parameter variable is a logical variable. Therefore, it doesn't survive from top-level query to top-level query:
?- array(Array)::(new(5,0), set(2, 7), get(2, Value)).
Array = a(0, 7, 0, 0, 0),
Value = 7.
?- array(Array)::new(5,0).
Array = a(0, 0, 0, 0, 0).
?- array(Array)::set(2, 7).
ERROR: Arguments are not sufficiently instantiated