Control.Monad.Squishy

Documentation

data Squishy s a

The Squishy monad is a monad with mutable references and optional reference identity

Instances

Monad (Squishy s)

Functor (Squishy s)

Applicative (Squishy s)

runSquishy :: forall a. (forall s. Squishy s a) -> a

Runs a Squishy computation, returning a pure value

data Identifier s

A unique identifier. Only possible to create while making a Distinct value.

Instances

Eq (Identifier s)

Ord (Identifier s)

data Distinct s a

Data with faked reference equality; the interface provided guarantees that every Distinct value has a unique Identifier.

Instances

Eq (Distinct s a)

Ord (Distinct s a)

distinguish :: a -> Squishy s (Distinct s a)

The only way to create a Distinct value is to generate a new identifier for it in the Squishy monad.

conflate :: Distinct s a -> a

Extracts the value stored in a Distinct

identify :: Distinct s a -> Identifier s

Extracts the unique identifier for a Distinct

data Ref s a

A mutable reference in the Squishy monad.

newRef :: a -> Squishy s (Ref s a)

Make a new reference.

readRef :: Ref s a -> Squishy s a

Read the value of a reference.

writeRef :: Ref s a -> a -> Squishy s ()

Write a new value to a reference.

modifyRef :: Ref s a -> (a -> a) -> Squishy s ()

Use the provided function to modify the contained value in a reference.