Control.AFSM

Arrowized functional state machines.

This module is inspired by Yampa and the paper Functional Reactive Programming, Continued* written by Henrik Nilsson, Antony Courtney and John Peterson.

Documentation

module Control.Arrow

data Event a

Constructors

E a

NoE

ErrE String

ExitE

Instances

Eq a => Eq (Event a)

Ord a => Ord (Event a)

Show a => Show (Event a)

The SM type

data SM a b

SM is a type representing a state machine.

Instances

Arrow SM

ArrowChoice SM

ArrowLoop SM

Category * SM

The SMState type

type SMState s a b = s -> a -> (SM a b, b)

Constructors

newSM :: s -> SMState s a b -> SM a b

newSM is the same with SM constructor.

simpleSM :: s -> (s -> a -> (s, b)) -> SM a b

simpleSM is to build a simple SM which have only one SMState.

Basic State Machines

constSM :: b -> SM a b

constSM build a SM which always return b

High order functions

execSM :: SM a b -> SM [a] [b]

execSM converts SM a b -> SM [a] [b], it is very useful to compose SM a [b] and SM b c to SM a [c].

Evaluation

exec :: SM a b -> [a] -> (SM a b, [b])

execute SM a b with input [a].