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The Monad language. Dependent types, functional programming compiled with LLVM. Hobby project.
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1234567891011121314151617181920212223242526272829303132333435363738394041424344454647484950515253545556575859606162class Semigroup A { def combine (a b : A) : A}class [Semigroup A] Monoid A { def mempty (u : Unit) : A}instance {A : Type} Semigroup (List A) { def combine (a b : List A) : List A := List.append a b}instance {A : Type} Monoid (List A) { def mempty (u : Unit) : List A := List.empty}instance Semigroup String { def combine (a b : String) : String := String.concat a b}instance Monoid String { def mempty (u : Unit) : String := ""}class Foldable (T : Type -> Type) { def foldr (f : A -> B -> B) (z : B) (t : T A) : B def foldl (f : B -> A -> B) (z : B) (t : T A) : B // foldMap [Monoid M] {A M : Type} (f : A -> M) (t : T A) : M -- requires constraint propagation}class [Foldable T] Traversable (T : Type -> Type) { def traverse [Applicative F] {A B : Type} (f : A -> F B) (t : T A) : F (T B)}instance Foldable List { def foldr (f : A -> B -> B) (z : B) (t : List A) : B := match t { empty => z, cons a tail => (f a (Foldable.foldr f z tail) : B) } def foldl (f : B -> A -> B) (z : B) (t : List A) : B := match t { empty => z, cons a tail => (Foldable.foldl f (f z a) tail : B) }}instance Foldable Option { def foldr (f : A -> B -> B) (z : B) (t : Option A) : B := match t { none => z, some a => f a z } def foldl (f : B -> A -> B) (z : B) (t : Option A) : B := match t { none => z, some a => f z a }}