Fantasy land sketch

fantasy_land.gleam

@@ -0,0 +1,83 @@
+pub type Setoid(t, r) = module { r |
+  fn equals(t, t) -> Bool
+};
+
+pub type Ord(t, r) = module { r |
+  fn less_than_equal(t, t) -> Bool
+};
+
+pub type Semigroup(t, r) = module { r |
+  fn concat(t, t) -> t
+};
+
+pub type Monoid(t, r) = Semigroup(t, module { r |
+  fn empty() -> t
+});
+
+pub type Group(t, r) = Monoid(t, module { r |
+  fn invert(t) -> t
+});
+
+pub type Semigroupoid(t, r) = module { r |
+  fn compose(t(i, j), t(j, k)) -> t(i, k)
+};
+
+pub type Category(t, r) = Semigroupoid(t, module { r |
+  fn id() -> t(i, k)
+});
+
+pub type Filterable(t, r) = module { r |
+  fn filter(t(a), fn(a) -> Bool) -> t(a)
+};
+
+pub type Functor(t, r) = module { r |
+  fn map(t(a), fn(a) -> b) -> t(b)
+};
+
+pub type Contravariant(t, r) = module { r |
+  fn contramap(t(b), fn(a) -> b) -> t(a)
+};
+
+pub type Apply(t, r) = Functor(t, module { r |
+  fn ap(t(fn(a) -> b), t(a)) -> t(b)
+});
+
+pub type Apply(t, r) = module { r |
+  fn ap(t(fn(a) -> b), t(a)) -> t(b)
+};
+
+pub type Applicative(t, r) = Apply(t, module { r |
+  fn of(a) -> t(a)
+});
+
+pub type Alt(t, r) = Functor(t, module { r |
+  fn alt(t(a), t(a)) -> t(a)
+});
+
+pub type Plus(t, r) = Alt(t, module { r |
+  fn zero() -> t(a)
+});
+
+pub type Alternative(t, r) = Applicative(t, Plus(t, r));
+
+pub type Chain(t, r) = Apply(t, module { r |
+  fn chain(t(a), fn(a) -> t(b)) -> t(b)
+});
+
+pub type Monad(t, r) = Applicative(t, Chain(t, r));
+
+pub type Foldable(t, r) = module { r |
+  fn reduce(t(b), a, fn(a) -> b) -> b
+};
+
+pub type Extend(t, r) = Functor(t, module { r |
+  fn extend(t(a), fn(t(a)) -> a) -> t(b)
+});
+
+pub type Comonad(t, r) = Extend(t, module { r |
+  fn extract(t(a)) -> a
+});
+
+pub type Traversable(t, r) = module { r |
+  fn traverse(t(a), Applicative(u), u(b)) -> u(t(b))
+};