!752

static class Source {

  S username, slackTS;

  long time;

}

static class Rel {

  Source source;

  S a, b; // the things to relate

  S name; // e.g. "is a"

  int score; // -1 (no), 0 (unknown), 1 (yes)

}

static new L<Rel> relations;

p {

  load("relations");

}

answer {

  if "* is a *" {

    saveRel(m.unq(0), m.unq(1), "is a", 1);

    ret "OK, relation saved.";

  }

  if "* is not a *" {

    saveRel(m.unq(0), m.unq(1), "is a", -1);

    ret "OK, anti-relation saved.";

  }

  if "number of relations"

    ret str(l(relations));

  if "list all relations"

    ret structure(relations);

  if "is * a *" {

    S a = m.unq(0), b = m.unq(1);

    int score = relScore(a, b, "is a");

    S answer = score < 0 ? "No, * is not a *"

      : score > 0 ? "Yes, * is a *"

      : "I'm not sure if * is a *.";

    ret format(answer, a, b);

  }

}

static void saveRel(S a, S b, S name, int score) {

  new Rel r;

  r.source = currentSource();

  r.a = a;

  r.b = b;

  r.name = name;

  r.score = score;

  relations.add(r);

  save("relations");

}

static Source currentSource() {

  new Source s;

  s.username = getUserName();

  s.slackTS = getSlackTS();

  s.time = now();

  ret s;

}

static int relScore(S a, S b, S name) {

  L<Rel> l = findRels(a, b, name);

  ret listScore(l);

}

static L<Rel> findRels(S a, S b, S name) {

  new L<Rel> l;

  for (Rel r : relations)

    if (eq(r.a, a) && eq(r.b, b) && eq(r.name, name))

      l.add(r);

  ret l;

}

static int listScore(L<Rel> l) {

  int min = 1, max = -1;

  for (Rel r : l) {

    min = min(min, r.score);

    max = max(max, r.score);

  }

  ret min != max ? 0 : min; // default to unknown

}