DDC.Control.Monad.Check

A simple exception monad.

Documentation

data CheckM s err a

Checker monad maintains some state and manages errors during type checking.

Constructors

CheckM (s -> (s, Either err a))

Instances

Monad (CheckM s err)

Functor (CheckM s err)

Applicative (CheckM s err)

throw :: err -> CheckM s err a

Throw a type error in the monad.

runCheck :: s -> CheckM s err a -> (s, Either err a)

Run a checker computation, returning the result and new state.

evalCheck :: s -> CheckM s err a -> Either err a

Run a checker computation, ignoreing the final state.

get :: CheckM s err s

Get the state from the monad.

put :: s -> CheckM s err ()

Put a new state into the monad.