Denotational semantic for the parse tree

denotational-semantic

newstore([]).

access(_,[],0).
access(I,[(I,V)|_],V).
access(I,[_|T],V) :- access(I,T,V).

update(I,NV,[],[(I,NV)]).
update(I,NV,[(I,_)|T],[(I,NV)|T]).
update(I,NV,[P|T],[P|T1]) :- update(I,NV,T,T1).

psem(pprog(K), A, B, D) :-              newstore(S),
                                        update(x, A, S, S1),
                                        update(y, B, S1, S2),
                                        ksem(K, S2, S3),
                                        access(z, S3, D).

ksem(pblock(D,C),Sin,Sout) :-           dsem(D,Sin,Sin1),
                                        csem(C,Sin1,Sout).

dsem(pdeclaration(D1,D2),Sin,Sout):- 	dsem(D1,Sin,Sin1),
                                        dsem(D2,Sin1,Sout).

dsem(pconstant(I,N),Sin,Sout):-         update(I,N,Sin,Sout).
                                        dsem(pvar(_),Sin,Sin).

csem(pcc(C1,C2),Sin,Sout):-             csem(C1,Sin,Sin1),
                                        csem(C2,Sin1,Sout).

csem(passignie(I,E),Sin,Sout):-         esem(E,Sin,Sin1,Val),
                                        update(I,Val,Sin1,Sout).

csem(pfullif(B,C1,C2),Sin,Sout):-       bsem(B,Sin,Sin1,RV),(RV -> csem(C1,Sin1,Sout) ; csem(C2,Sin1,Sout)).

csem(pwhile(B,C),Sin,Sout):-            bsem(B,Sin,Sin1,RV),(RV -> csem(C,Sin1,Sin2),csem(pwhile(B,C),Sin2,Sout) ; Sout=Sin1).

esem(pi(I),Sin,Sin,Val):-               access(I,Sin,Val).

esem(pn(N),Sin,Sin,N).

esem(pe(E),Sin,Sout,Value):-            esem(E,Sin,Sout,Value).

esem(passign(I,E),Sin,Sout,Value):-     esem(E,Sin,Sin1,Value),
                                        update(I,Value,Sin1,Sout).

esem(padd(E1,E2),Sin,Sout,Value):-      esem(E1,Sin,Sin1,Value1),
                                        esem(E2,Sin1,Sout,Value2),
                                        Value is Value1 + Value2.

esem(psubtract(E1,E2),Sin,Sout,Value):- esem(E1,Sin,Sin1,Value1),
                                        esem(E2,Sin1,Sout,Value2),
                                        Value is Value1 - Value2.

esem(pmul(E1,E2),Sin,Sout,Value):-      esem(E1,Sin,Sin1,Value1),
                                        esem(E2,Sin1,Sout,Value2),
                                        Value is Value1 * Value2.

esem(pdiv(E1,E2),Sin,Sout,Value):-      esem(E1,Sin,Sin1,Value1),
                                        esem(E2,Sin1,Sout,Value2),
                                        Value is Value1 / Value2.

bsem(passignequal(E1,E2),Sin,Sout,RV):-	esem(E1,Sin,Sin1,Value1),
                                        esem(E2,Sin1,Sout,Value2),
                                        (Value1=Value2 -> RV = true ; RV = false).

bsem(pnot(B),Sin,Sout,RV):-             bsem(B,Sin,Sout,RV1),
                                        (RV1 -> RV = false ; RV = true).
bsem(pbbrace(B),Sin,Sout,RV):-          bsem(B,Sin,Sout,RV).
bsem(ptrue(true),_,_,true).
bsem(pfalse(false),_,_,false).

main(ValX, ValY, A) :- program(P, [begin, var, x, ;, var, y, ;, var,z, ;, var, w, ;, z, :=, 1, ;, w, :=, x, ;, while, w, >, 0, do, z, :=,z, *, y, ;, w, :=, w, -, 1, endwhile, end, .],[]), write(P),
    psem(P,ValX,ValY,A).