Lazy deduplication of lazy lists

def MLList.dedupBy {m : Type → Type} {β : Type} [Monad m] [BEq β] [Hashable β] {α : Type} (L : MLList m α) (f : α → m β) : MLList m α

Lazily deduplicate a lazy list, using a stored HashMap.

def MLList.dedup {m : Type → Type} {β : Type} [Monad m] [BEq β] [Hashable β] (L : MLList m β) : MLList m β

Lazily deduplicate a lazy list, using a stored HashMap.