triska

68 ms·

1. 511.▲
   by triska 9y ago

   This comment contains an important key distinction between different usages of "=" that are often casually intermixed in such discussions: There is a major difference in how we quantify the logical variables that occur in formul
2. 512.▲
   by triska 9y ago

   Yes, that's also possible with this definition! For example: Given Ls0 = [a,b,c] and Ls = [a,c], which element (if any) was dropped: ?- drop(X, [a,b,c], [a,c]). X = b ; false. As another example, if both Ls0 and Ls a
3. 513.▲
   by triska 9y ago

   To illustrate how close Erlang syntax is to Prolog, here is drop/3 in Prolog: drop(X, List, Result) :- drop(X, List, [], Result). drop(_, [], Acc, Result) :- reverse(Acc, Result). drop(X, [X|Rest], Acc, Result) :- drop(X
4. 514.▲
   by triska 9y ago

   Prolog is a good example of a language where "=" doesn't mean assignment. In Prolog, "=" means unification : You can read X = Y (which is =(X, Y) in functional notation) as: "True iff X and Y are unifiable
5. 515.▲
   by triska 9y ago

   Very nice reflection on an important and enjoyable topic! Regarding the question at the end about "a more general term for this kind of 'passing through' of functionality": At least in the context of Prolog meta-interpre
6. 516.▲
   by triska 9y ago

   Picat has a built-in planner that enables some interesting solutions to planning tasks. Picat has strong built-in support for important constraints , notably constraints over finite domains which is a very important paradigm for solving
7. 517.▲
   by triska 9y ago

   In a sense, if you already understand functional programming, then the leap to logic programming is comparatively straight-forward: Say you have a function f with N arguments that yields a value y. That is, you have y = f(x_1,...,x_N). Then