Files
linguist/samples/Prolog/calc.pl
Joshua Peek d2de997fcc Add more Prolog samples
Closes #233
2012-08-20 10:48:36 -05:00

69 lines
1.9 KiB
Prolog

action_module(calculator) .
%[-,-,d1,-] --push(D)--> [-,-,D,-] if mode(init)
push(D) < -
mode(init),
deny([displayed(D1),mode(init)]),
affirm([displayed(D),mode(cont)]).
%[-,-,D1,-] --push(D)--> [-,-,10*D1+D,-] if mode(cont)
push(D) < -
mode(cont),
deny(displayed(D1)),
New = 10*D1 + D,
affirm(displayed(New)).
%[a,op,d,m] --push(clear)--> [0,nop,0,0]
push(clear) < -
deny([accumulator(A),op(O),displayed(D),memory(M),mode(X)]),
affirm([accumulator(0),op(nop),displayed(0),memory(0),mode(init)]).
%[a,op,d,m] --push(mem_rec)--> [a,op,m,m]
push(mem_rec) < -
memory(M),
deny([displayed(D),mode(X)]),
affirm([displayed(M),mode(init)]).
%[a,op,d,m] --push(plus)--> [op(a,d),plus,d,m]
push(plus) < -
displayed(D),
deny([accumulator(A),op(O),mode(X)]),
eval(O,A,D,V), ; use normal arithmetic, i.e., V=O(A,D)
affirm([accumulator(V),op(plus),mode(init)]).
%[a,op,d,m] --push(minus)--> [op(a,d,minus,d,m]
push(minus) lt -
displayed(D),
deny([accumulator(A),op(O),mode(X)]),
eval(O,A,D,V), ; use normal arithmetic, i.e., V=O(A,D)
affirm([accumulator(V),op(minus),mode(init)]).
%[a,op,d,m] --push(times)--> [op(a,d),times,d,m]
push(times) < -
displayed(D),
deny([accumulator(A),op(O),mode(X)]),
eval(O,A,D,V), ; use normal arithmetic, i.e., V=O(A,D)
affirm([accumulator(V),op(times),mode(init)]).
%[a,op,d,m] --push(equal)--> [a,nop,op(a,d),m]
push(equal) < -
accumulator(A),
deny([op(O),displayed(D),mode(X)]),
eval(O,A,D,V),
affirm([op(nop),displayed(V),mode(init)]).
%[a,op,d,m] --push(mem_plus)--> [a,nop,v,plus(m,v)] where v=op(a,d)
push(mem_plus) < -
accumulator(A),
deny([op(O),displayed(D),memory(M),mode(X)]),
eval(O,A,D,V),
eval(plus,M,V,V1),
affirm([op(nop),displayed(V),memory(V1),mode(init)]).
%[a,op,d,m] --push(plus_minus)--> [a,op,-d,m]
push(clear) < -
deny([displayed(D),mode(X)]),
eval(minus,0,D,V),
affirm([displayed(V),mode(init)]).