Minimal live coding library for model-view-event-update applications.

Minimal live coding library. It can store model of the model-view-event-update applications. It uses FromJSON and ToJSON with default value for absent data elements, and Generic parser otherwise:

import Control.Restartable.Initially(initially, Initial)

data MyModel = Model { timestamp :: UTCTime }

instance ToJSON MyModel where
instance FromJSON MyModel where
  parseJSON = initially myDefaultValue
instance Initial MyModel

Then in the main module use:

import Control.Restartable.Checkpoint(restartable, Ending(..))

main = restartable "checkpoint.save" myMain

myMain :: MyModel -> IO (MyModel, Ending)

It is preferred to attach initial value to every substructure, so whenever it fails to parse the remaining part of the state is still parsed correctly.