@hackage/either
Combinators for working with sums
@hackage/base
Core data structures and operations
@hackage/mtl
Monad classes for transformers, using functional dependencies
@hackage/data-ref
Unify STRef and IORef in plain Haskell 98
@hackage/transformers
Concrete functor and monad transformers
@hackage/parsec
Monadic parser combinators