Yogurt-0.2: A MUD client library Source code Contents Index

Network.Yogurt.Mud

Contents Types Hooks Hook record fields Match information Variables Timers Timer record fields Triggering hooks IO

Description

The core of Yogurt, consisting of the Mud monad and all functions manipulating this monad.

Synopsis

type Mud = State MudState data MudState emptyMud :: MudState data Hook data Destination = Local | Remote type Pattern = String data Timer type Interval = Int data Result = Send Destination String | forall a . RunIO (IO a) (a -> Mud ()) | NewTimer Timer mkHook :: Destination -> Pattern -> Mud a -> Mud Hook mkPrioHook :: Int -> Destination -> Pattern -> Mud a -> Mud Hook setHook :: Hook -> Mud () rmHook :: Hook -> Mud () allHooks :: Mud [Hook] hPriority :: Hook -> Int hDestination :: Hook -> Destination hPattern :: Hook -> Pattern hAction :: Hook -> Mud () triggeredHook :: Mud Hook matchedLine :: Mud String before :: Mud String group :: Int -> Mud String after :: Mud String mkVar :: a -> Mud (Var a) setVar :: Var a -> a -> Mud () readVar :: Var a -> Mud a modifyVar :: Var a -> (a -> a) -> Mud () mkTimer :: Interval -> Mud a -> Mud Timer rmTimer :: Timer -> Mud () existsTimer :: Timer -> Mud Bool allTimers :: Mud [Timer] tAction :: Timer -> Mud () tInterval :: Timer -> Interval trigger :: Destination -> String -> Mud () triggerJust :: (Hook -> Bool) -> Destination -> String -> Mud () io :: Destination -> String -> Mud () flushResults :: Mud [Result] withIO :: IO a -> (a -> Mud ()) -> Mud () runIO :: IO a -> Mud ()

Types

type Mud = State MudState Source

The Mud monad is a simple state monad.

data MudState Source

State internal to the Mud monad.

emptyMud :: MudState Source

The initial state of the Mud monad.

data Hook Source

The abstract Hook type. Two hooks are considered equal if they were created (using mkHook) at the same time. Hook h1 < hook h2 if h1 will match earlier than h2. Instances Eq Hook Ord Hook Show Hook

data Destination Source

Used to distinguish between messages going in different directions. Constructors Local The message is headed towards the user's terminal. Remote The message is headed towards the remote MUD server. Instances Enum Destination Eq Destination Ord Destination Read Destination Show Destination

type Pattern = String Source

A Pattern is a regular expression.

data Timer Source

The abstract Timer type.

type Interval = Int Source

Interval in milliseconds.

data Result Source

A Result is a consequence of executing a Mud program. Constructors Send Destination String forall a . RunIO (IO a) (a -> Mud ()) NewTimer Timer

Hooks

A hook watches a channel for messages matching a specific regular expression. When a hook fires, the triggering message is consumed and the hook's action is executed. When a message doesn't trigger any hooks, it is sent on to its destination. A hook's action may query for match-specific data; see section Match Information. At most one hook fires for each message, unless the hook's action explicitly sends the message through trigger again. If several hooks match, only the hook with the highest priority fires. If there is still a tie, the hook that was defined last (using mkHook) fires.

mkHook :: Destination -> Pattern -> Mud a -> Mud Hook Source

Calls mkPrioHook with priority 0.

mkPrioHook :: Int -> Destination -> Pattern -> Mud a -> Mud Hook Source

Creates and installs a hook that watches messages headed to the specified destination and match the specified pattern.

setHook :: Hook -> Mud () Source

Saves a changed hook, or reactivates it.

rmHook :: Hook -> Mud () Source

Disables a hook.

allHooks :: Mud [Hook] Source

Yields all current hooks in preferred firing order.

Hook record fields

Use these in combination with setHook to update hooks.

hPriority :: Hook -> Int Source

Yields the hook's priority.

hDestination :: Hook -> Destination Source

Yields the destination this hook watches.

hPattern :: Hook -> Pattern Source

Yields the pattern messages must have for this hook to fire.

hAction :: Hook -> Mud () Source

Yields the Mud program to execute when the hook fires.

Match information

Functions for querying the currently firing hook. These functions should only be called from within a hook's body.

triggeredHook :: Mud Hook Source

Yields the hook that is currently firing.

matchedLine :: Mud String Source

Yields the message that triggered the currently firing hook.

before :: Mud String Source

Yields the part of the triggering message that comes before the matched pattern.

group :: Int -> Mud String Source

Yields the regex group from the matched pattern. group 0 yields the complete match; higher indices correspond to the parenthesized groups.

after :: Mud String Source

Yields the part of the triggering message that comes after the matched pattern.

Variables

mkVar :: a -> Mud (Var a) Source

Creates a variable with an initial value.

setVar :: Var a -> a -> Mud () Source

Updates a variable to a new value.

readVar :: Var a -> Mud a Source

Yields the variable's current value.

modifyVar :: Var a -> (a -> a) -> Mud () Source

Updates the variable using the update function.

Timers

mkTimer :: Interval -> Mud a -> Mud Timer Source

mkTimer interval prog creates a timer that executes prog every interval milliseconds.

rmTimer :: Timer -> Mud () Source

Disables the timer.

existsTimer :: Timer -> Mud Bool Source

Checks whether a timer is active.

allTimers :: Mud [Timer] Source

Yields all currently active timers.

Timer record fields

tAction :: Timer -> Mud () Source

Yields the timer's action.

tInterval :: Timer -> Interval Source

Yields the timer's interval.

Triggering hooks

trigger :: Destination -> String -> Mud () Source

Short for triggerJust (const True).

triggerJust :: (Hook -> Bool) -> Destination -> String -> Mud () Source

If the message triggers a hook that passes the specified test, it is fired. Otherwise, the message is passed on to the destination using io.

io :: Destination -> String -> Mud () Source

Immediately write a message to a destination, without triggering hooks.

flushResults :: Mud [Result] Source

Yields all accumulated results and removes them from the state. Used by Network.Yogurt.Engine in runMud.

IO

withIO :: IO a -> (a -> Mud ()) -> Mud () Source

Executes the IO action soon. The computation's result is passed to the function, and the resulting Mud computation is executed.

runIO :: IO a -> Mud () Source

Invokes withIO, discarding the IO's result.

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