Game.LambdaHack.Action.ActionLift

Game action monad and basic building blocks for player and monster actions. Exports liftIO for injecting IO into the Action monad, but does not export the implementation of the Action monad. The liftIO and handlerToIO operations are used only in Action.hs.

Actions and basic operations

type ActionFun r a

Arguments

 = Session

session setup data

-> DungeonPerception

cached perception

-> (State -> Diary -> a -> IO r)

continuation

-> (Msg -> IO r)

failure/reset continuation

-> State

current state

-> Diary

current diary

-> IO r

The type of the function inside any action. (Separated from the Action type to document each argument with haddock.)

data Action a

Actions of player-controlled characters and of any other actors.

Instances

Monad Action

Functor Action

MonadState State Action

Show (Action a)

liftIO :: IO a -> Action a

handlerToIO :: Session -> State -> Diary -> Action () -> IO ()

Run an action, with a given session, state and diary, in the IO monad.

withPerception :: Action () -> Action ()

Update the cached perception for the given computation.

getPerception :: Action Perception

Get the current perception.

Actions returning frames

type ActionFrame a = Action (a, [Maybe SingleFrame])

Actions and screen frames, including delays, resulting from performing the actions.

returnNoFrame :: a -> ActionFrame a

Return the value with an empty set of screen frames.

returnFrame :: SingleFrame -> ActionFrame ()

Return the trivial value with a single frame to show.

whenFrame :: Bool -> ActionFrame () -> ActionFrame ()

As the when monad operation, but on type ActionFrame ().

inFrame :: Action () -> ActionFrame ()

Inject action into actions with screen frames.

Game session and assessors to its components

data Session

The information that is constant across a playing session, including many consecutive games in a single session, but is completely disregarded and reset when a new playing session starts.

Constructors

Session

Fields

sfs :: FrontendSession

frontend session information

scops :: COps

game content

sbinding :: Binding (ActionFrame ())

binding of keys to commands

sconfigUI :: ConfigUI

the UI config for this session

getFrontendSession :: Action FrontendSession

Get the frontend session.

getCOps :: Action COps

Get the content operations.

getBinding :: Action (Binding (ActionFrame ()))

Get the key binding.

getConfigUI :: Action ConfigUI

Get the config from the config file.

Various ways to abort action

abort :: Action a

Reset the state and resume from the last backup point, i.e., invoke the failure continuation.

abortWith :: Msg -> Action a

Abort with the given message.

abortIfWith :: Bool -> Msg -> Action a

Abort and print the given msg if the condition is true.

neverMind :: Bool -> Action a

Abort and conditionally print the fixed message.

Abort exception handlers

tryWith :: (Msg -> Action a) -> Action a -> Action a

Set the current exception handler. First argument is the handler, second is the computation the handler scopes over.

tryRepeatedlyWith :: (Msg -> Action ()) -> Action () -> Action ()

Take a handler and a computation. If the computation fails, the handler is invoked and then the computation is retried.

tryIgnore :: Action () -> Action ()

Try the given computation and silently catch failure.

Diary and report

getDiary :: Action Diary

Get the current diary.

msgAdd :: Msg -> Action ()

Add a message to the current report.

historyReset :: History -> Action ()

Wipe out and set a new value for the history.

msgReset :: Msg -> Action ()

Wipe out and set a new value for the current report.