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Code: Select all

predicates
    findPath : (string Start, string End) -> string* Path determ.
clauses
    findPath(Start, End) = list::reverse(findPath2(Start, End, [Start])).<<<<<error
 
predicates
    findPath2 : (string Start, string End, string* PathSoFar) -> string Path determ.
clauses
    findPath2(C, C, PathSoFar) = [C|PathSoFar] :-<<<<<error
        !.
 
    findPath2(A, C, PathSoFar) = Path :-
        edge(A, B),
        not(list::isMember(B, PathSoFar)),
        Path = findPath2(A, B, [B|PathSoFar]),
        !.

Code: Select all

Network.pro(47,38) error c504: The expression has type '::string', which is incompatible with the type '::string*'
 
Network.pro(49,34) error c504: The expression has type 'a$*', which is incompatible with the type '::string'

Code: Select all

predicates
    findPath : (string Start, string End) -> string* Path determ.
clauses
    findPath(Start, End) = list::reverse(findPath2(Start, End, [Start])).  %Input to this predicate is string list - so you must return string list from the findPath2/..  predicate 
 
predicates
    findPath2 : (string Start, string End, string* PathSoFar) -> string* Path determ.  %return type must be stirng list
clauses
    findPath2(C, C, PathSoFar) = [C|PathSoFar] :-
        !.
    findPath2(A, C, PathSoFar) = Path :-
        edge(A, B),
        not(list::isMember(B, PathSoFar)),
        !,
        Path = findPath2(A, B, [B|PathSoFar]).
        
predicates
    edge : (string, string[out]).
clauses
    edge("A", "B"):-!.
    edge(_, "").