examples/basics/password.pl

@@ -1,19 +0,0 @@
-login :-
-    getdata(_, _),
-    writeln('Welcome!').
-login :-
-    repeat,
-    writeln('Sorry, you are not permitted.'),
-    getdata(_, _),
-    writeln('Welcome').
-
-getdata(Name, Password) :-
-    write('Username: '),
-    read(Name),
-    write('Password: '),
-    read(Password),
-    user(Name, Password).
-
-user(john, john1).
-user(jimmy, jimmy1).
-user(mary, mary1).

examples/basics/repeat.pl

@@ -1,2 +0,0 @@
-repeat.
-repeat :- repeat.

examples/basics/summer.pl

@@ -14,9 +14,9 @@ my_sum :-
     write('The sum is: '),
     write(Sum), nl.
 
-summer_main :-
+main :-
     Start = 1, End = 9,
     summer(Start, End, Sum),
     write('The sum of '), write(Start), write(' to '), write(End), write(' is: '), write(Sum), nl.
 
-:- initialization(summer_main).
+:- initialization(main).

examples/demo.pl

@@ -1,164 +0,0 @@
-:- initialization(demo).
-
-% % % % % % % % % %
-% DEMO MENU LOGIC %
-% % % % % % % % % %
-
-demo :-
-    clear,
-    header,
-    menu.
-
-menu :-
-    nl,
-    options,
-    write('DEMO: Enter your choice: '),
-    read(Choice),
-    choice(Choice).
-
-header :-
-    writeln('* * * * * * * * * * * * * * * * * * * * * * * * *'),
-    writeln('*               GHENT PROLOG DEMO               *'),
-    writeln('* * * * * * * * * * * * * * * * * * * * * * * * *').
-
-options :-
-    writeln('-------------------------------------------------'),
-    writeln('INPUT DESCRIPTION              CATEGORY SOURCE'),
-    writeln('-------------------------------------------------'),
-    writeln('(1)   A password prompt        basics   password.pl'),
-    writeln('(2)   Add i in [a..b]          maths    summer.pl'),
-    writeln('(3)   A translator             meta     mib_voorbeelden.pl'),
-    writeln('(4)   A tale of a ceremony     cont.    ceremony.pl'),
-    writeln('(5)   Maths with Shift/Reset   cont.    continuations.pl'),
-%    writeln('(6)   Alternative lists        meta     my_list.pl'),
-    nl,
-    writeln('(interpreter) to enter the interpreter'),
-    writeln('(exit)        to exit the demo'),
-    nl.
-
-choice(1) :- !, run_login_example, menu.
-choice(2) :- !, run_summer_example, menu.
-choice(3) :- !, run_mib_voorbeelden_example, continue, menu.
-choice(4) :- !, run_ceremony_example, continue, menu.
-choice(5) :- !, run_continuations_example, continue, menu.
-%choice(6) :- !, run_my_list_example, continue, menu.
-choice(interpreter) :- !, run_interpreter, continue, menu.
-choice(exit) :- !, writeln('Exiting...').
-choice(_) :- write('DEMO: Invalid choice, please try again: '), read(Choice), choice(Choice).
-
-% % % % % % % % % %
-% DEMO REPOSITORY %
-% % % % % % % % % %
-
-run_login_example :-
-    say('Loading login example...'),
-    consult('examples/basics/repeat.pl'),
-    consult('examples/basics/password.pl'),
-    say('Showing login/0'),
-    say('You might try logging in with tibo/noaccess and john/john1.'),
-    login, login_example_loop, !,
-    say('Login example finished.').
-
-login_example_loop :-
-    yes_or_no('Do you want to try again?', (login, login_example_loop), true).
-
-run_summer_example :-
-    say('Loading summer example...'),
-    consult('examples/basics/summer.pl'),
-    say('Showing my_sum/1'),
-    say('You might try summing 1 to 9.'),
-    my_sum, summer_example_loop, !,
-    say('Summer example finished.').
-
-summer_example_loop :-
-    yes_or_no('Do you want to try again?', (my_sum, summer_example_loop), true).
-
-run_mib_voorbeelden_example :-
-    say('Loading mib_voorbeelden example...'),
-    consult('examples/meta/mib_voorbeelden.pl'), clear,
-    say('Showing example1/0'), example1, next((
-    say('Showing example2/0'), example2, next((
-    say('Showing example3/0'), example3)))),
-    say('mib_voorbeelden example finished.').
-
-run_ceremony_example :-
-    say('Loading ceremony example...'),
-    consult('examples/meta/ceremony.pl'), clear,
-    say('Showing ceremony_main/0'),
-    ceremony_main,
-    say('Ceremony example finished.').
-
-run_continuations_example :-
-    say('Loading continuations example...'),
-    consult('examples/meta/continuations.pl'), clear,
-    say('Showing continuations_main/0'),
-    continuations_main,
-    say('Continuations example finished.').
-
-run_my_list_example :-
-    say('Loading my_list example...'),
-    consult('examples/meta/my_list.pl'),
-    say('Showing my_member/2'),
-    showcase(my_member(X, a(b(c))), 'X', X),
-    continue,
-    say('Showing my_length/2'),
-    showcase(my_length(a(b(c)), Length), 'Length', Length),
-    say('my_list example finished.').
-
-run_interpreter :-
-    say('Loading interpreter...'),
-    consult('examples/meta/ground.pl'),
-    consult('examples/meta/interpreter.pl'),
-    say('Showing interpreter/0'),
-    say('Have fun!'),
-    interpreter,
-    say('Interpreter finished.').
-
-% % % % % % % % % % %
-% HELPER PREDICATES %
-% % % % % % % % % % %
-
-yes_or_no(Question, IfYes, IfNo) :-
-    write(Question), write(' (y/n): '),
-    read(Answer),
-    ( ( was_yes(Answer), !, call(IfYes)) ; ( was_no(Answer), !, call(IfNo))).
-
-was_yes(y).
-was_yes('Y').
-was_yes(yes).
-was_yes('Yes').
-was_yes('YES').
-
-was_no(n).
-was_no('N').
-was_no(no).
-was_no('No').
-was_no('NO').
-
-say(Message) :-
-    write('DEMO: '),
-    writeln(Message).
-
-showcase(Goal, VarName, Var) :-
-    say(Goal),
-    call(Goal),
-    say(solution(VarName, Var)).
-
-showcase(Goal) :-
-    Goal =.. List,
-    say(List),
-    call(Goal).
-
-next(Next) :- yes_or_no('See next?', call(Next), true).
-
-continue :-
-    write('Write anything to continue... '),
-    read(_).
-
-clear :- clear(30).
-
-clear(0) :- !.
-clear(N) :-
-    nl,
-    M is N - 1,
-    clear(M).

examples/meta/calculator.pl

@@ -0,0 +1,15 @@
+accumulator :-
+    Sum = 0,
+    shift(Number),
+    NewSum is Sum + Number,
+    write("Result is: "), writeln(NewSum).
+
+main :-
+    reset(accumulator, Number, Cont),
+    between(1, 5, Number),
+    forall()
+    call(Cont),
+    writeln("End of calculation").
+
+:- initialization(main).
+

examples/meta/ceremony.pl

@@ -4,7 +4,7 @@ printer :-
     shift(Name),
     write(Name), write(", ").
 
-ceremony_main :-
+main :-
     writeln("/Ceremony starts/"),
     reset(printer, Name, Cont),
     \+ \+ ( Name = "John", call(Cont) ),
@@ -12,4 +12,4 @@ ceremony_main :-
     writeln("and my parents!"),
     writeln("/Ceremony ends/").
 
-:- initialization(ceremony_main).
+:- initialization(main).

examples/meta/continuations.pl

@@ -12,11 +12,11 @@ test_ :-
     X is 1 + (2 * Y),
     write("In test X = "), write(X), writeln("; done").
 
-continuations_main :-
+main :-
     test(Cont, Term),
     \+ \+ ( writeln("Calling Cont(2)"),
             Term = 2, call(Cont)),
     \+ \+ ( writeln("Calling Cont(4)"),
             Term = 4, call(Cont)).
 
-:- initialization(continuations_main).
+:- initialization(main).

examples/meta/ground.pl

@@ -1,15 +0,0 @@
-ground(T) :-
-    nonvar(T), atomic(T),
-    !.
-ground(T) :-
-    nonvar(T), compound(T),
-    functor(T, _, N),
-    ground(T, N).
-
-ground(T, N) :-
-    N \== 0,
-    arg(N, T, A),
-    ground(A),
-    M is N - 1,
-    ground(T, M).
-ground(T, 0).

examples/meta/interpreter.pl

@@ -1,27 +0,0 @@
-interpreter :-
-    interpreter_prompt,
-    read(Goal),
-    interpreter(Goal).
-
-interpreter_prompt :- write('Next Command ?-- ').
-
-interpreter(exit) :- !.
-interpreter(Goal) :-
-    ground(Goal), !,
-    solve_ground(Goal),
-    interpreter.
-interpreter(Goal) :-
-    solve(Goal),
-    interpreter.
-
-solve_ground(Goal) :-
-    call(Goal),
-    !,
-    writeln('True :)').
-solve_ground(_) :- writeln('False :(').
-
-solve(Goal) :-
-    call(Goal),
-    writeln(Goal),
-    fail.
-solve(_) :- writeln('No more solutions :/').

examples/meta/mib_voorbeelden.pl

@@ -40,9 +40,9 @@ example3 :-
     mib(f, e, Result2, Result3),
     write(Result3), nl.
 
-mib_main :-
+main :-
     example1,
     example2,
     example3.
 
-:- initialization(mib_main).
+:- initialization(main).

examples/meta/my_list.pl

@@ -1,14 +0,0 @@
-% my_member(Element, List) - checks if Element is in List
-my_member(Element, Element) :- atomic(Element).
-my_member(Element, Compound) :-
-    compound(Compound),
-    Compound =.. [Head, Tail],
-    (Element = Head ; my_member(Element, Tail)).
-
-% my_length(List, Length) - finds the my_length of a list
-my_length(Atom, 1) :- atomic(Atom).
-my_length(Compound, N) :-
-    compound(Compound),
-    Compound =.. [_, Tail],
-    my_length(Tail, M),
-    N is M + 1.

src/prolog/builtins/analysisOperators.kt

@@ -159,31 +159,27 @@ class ClauseOp(private val head: Head, private val body: Body) :
 
 open class Univ(private val term: Term, private val list: Term) : Operator("=..", term, list) {
     override fun satisfy(subs: Substitutions): Answers {
-        if (variable(term, subs)) {
-            require(nonvariable(list, subs)) { "Arguments are not sufficiently instantiated" }
-            val l = applySubstitution(list, subs) as List
-            require(nonvariable(l.head, subs)) { "Arguments are not sufficiently instantiated" }
-
-            val t = listToTerm(l)
-            return unifyLazy(term, t, subs)
-        }
-
-        if (nonvariable(list, subs)) {
-            val l = applySubstitution(list, subs) as List
-
-            if (nonvariable(l.head, subs)) {
+        return when {
+            nonvariable(term, subs) && nonvariable(list, subs) -> {
                 val t = applySubstitution(term, subs)
-                return unifyLazy(t, listToTerm(l), subs)
+                val l = applySubstitution(list, subs) as List
+                unifyLazy(t, listToTerm(l), subs)
             }
 
-            val t = applySubstitution(term, subs)
-            val expectedL = termToList(t)
-            return unifyLazy(expectedL, l, subs)
-        }
+            variable(term, subs) && nonvariable(list, subs) -> {
+                val l = applySubstitution(list, subs) as List
+                val t = listToTerm(l)
+                unifyLazy(term, t, subs)
+            }
 
-        val t = applySubstitution(term, subs)
-        val l = termToList(t)
-        return unifyLazy(l, list, subs)
+            nonvariable(term, subs) && variable(list, subs) -> {
+                val t = applySubstitution(term, subs)
+                val l = termToList(t)
+                unifyLazy(l, list, subs)
+            }
+
+            else -> throw Exception("Arguments are not sufficiently instantiated")
+        }
     }
 
     protected open fun listToTerm(list: List): Term {

src/repl/Repl.kt

@@ -20,7 +20,6 @@ class Repl {
                 printAnswers(query())
             } catch (e: Exception) {
                 Logger.error("Error parsing REPL: ${e.message}")
-                Logger.debug(e.stackTraceToString())
             }
         }
     }

tests/prolog/builtins/AnalysisOperatorsTests.kt

@@ -568,23 +568,6 @@ class AnalysisOperatorsTests {
             assertEquals(0, result.size, "Expected 0 results")
         }
 
-        @Test
-        fun `univ extra debugging`() {
-            val univ = Univ(
-                Structure("baz", Variable("Foo")),
-                Cons(Variable("Baz"), Cons(Structure("foo", Integer(1)), Empty))
-            )
-
-            val result = univ.satisfy(emptyMap()).toList()
-
-            assertEquals(1, result.size, "Expected 1 result")
-            assertTrue(result[0].isSuccess, "Expected success")
-            val subs = result[0].getOrNull()!!
-            assertEquals(2, subs.size, "Expected 2 substitutions")
-            assertEquals(Atom("baz"), subs[Variable("Baz")], "Expected Baz to be baz")
-            assertEquals(Structure("foo", Integer(1)), subs[Variable("Foo")], "Expected Foo to be foo(1)")
-        }
-
         @Test
         fun `univ with two vars should throw`() {
             val univ = Univ(Variable("X"), Variable("Y"))