Copyright | (C) 2016 Chris Penner |
---|---|
License | MIT |
Maintainer | Chris Penner <christopher.penner@gmail.com> |
Safe Haskell | None |
Language | Haskell2010 |
This module contains the public API for building an extension for Rasa. It re-exports the parts of rasa that are public API for creating extensions.
There are two main things that an extension can do, either react to editor events, or expose useful actions and/or state for other extensions to use.
Whether performing its own actions or being used by a different extension
an extension will want to define some Action
s to perform. Actions
can operate over buffers or even perform IO and comprise the main way in which
extensons do what they need to do. Read more here: Action
, BufAction
.
To sum it all up, Here's an example of a simple logging extension that simply writes each keypress to a file.
logKeypress :: Keypress -> Action () logKeypress (Keypress char _) = liftIO $ appendFile "logs" ("You pressed " ++ [char] ++ "\n") logger :: Action () logger = do onInit $ liftIO $ writeFile "logs" "==Logs==\n" -- Listeners should also be registered using 'onInit'. -- It ensures all listeners are ready before any actions occur. onInit $ onEveryTrigger_ logKeypress onExit $ liftIO $ appendFile "logs" "==Done=="
Check out this tutorial on building extensions, it's also just a great way to learn how the editor works: Extension-Guide.
- data Action a
- exit :: Action ()
- newBuffer :: YiString -> Action BufRef
- nextBufRef :: BufRef -> Action BufRef
- prevBufRef :: BufRef -> Action BufRef
- getBufRefs :: Action [BufRef]
- getBuffers :: Action [(BufRef, Buffer)]
- getBuffer :: BufRef -> Action (Maybe Buffer)
- data Buffer
- class HasBuffer a where
- data BufRef
- text :: HasBuffer b => Lens' b YiString
- class HasEditor a
- getText :: BufAction YiString
- getRange :: CrdRange -> BufAction YiString
- data BufAction a
- liftAction :: Action r -> BufAction r
- bufDo :: BufRef -> BufAction a -> Action (Maybe a)
- bufDo_ :: BufRef -> BufAction a -> Action ()
- buffersDo :: BufAction a -> Action [a]
- buffersDo_ :: BufAction a -> Action ()
- overRange :: CrdRange -> (YiString -> YiString) -> BufAction ()
- replaceRange :: CrdRange -> YiString -> BufAction ()
- deleteRange :: CrdRange -> BufAction ()
- insertAt :: Coord -> YiString -> BufAction ()
- sizeOf :: YiString -> Coord
- class HasExts s where
- ext :: forall a e. (Show a, Typeable a, Default a, HasExts e) => Lens' e a
- class HasBufExts s where
- bufExt :: forall a s. (Show a, Typeable a, Default a, HasBufExts s) => Lens' s a
- data Keypress
- data Mod
- data ListenerId
- dispatchEvent :: Typeable a => a -> Action ()
- onEveryTrigger :: forall a b. Typeable a => (a -> Action b) -> Action ListenerId
- onEveryTrigger_ :: forall a b. Typeable a => (a -> Action b) -> Action ()
- onNextEvent :: forall a b. Typeable a => (a -> Action b) -> Action ()
- removeListener :: ListenerId -> Action ()
- onInit :: forall a. Action a -> Action ()
- beforeEveryEvent :: forall a. Action a -> Action ListenerId
- beforeEveryEvent_ :: forall a. Action a -> Action ()
- beforeNextEvent :: forall a. Action a -> Action ()
- beforeEveryRender :: forall a. Action a -> Action ListenerId
- beforeEveryRender_ :: forall a. Action a -> Action ()
- beforeNextRender :: forall a. Action a -> Action ()
- onEveryRender :: forall a. Action a -> Action ListenerId
- onEveryRender_ :: forall a. Action a -> Action ()
- onNextRender :: forall a. Action a -> Action ()
- afterEveryRender :: forall a. Action a -> Action ListenerId
- afterEveryRender_ :: forall a. Action a -> Action ()
- afterNextRender :: forall a. Action a -> Action ()
- onExit :: forall a. Action a -> Action ()
- onBufAdded :: forall a. (BufRef -> Action a) -> Action ListenerId
- onBufTextChanged :: forall a. (CrdRange -> YiString -> Action a) -> Action ListenerId
- type Dispatcher = forall a. Typeable a => a -> IO ()
- dispatchActionAsync :: IO (Action ()) -> Action ()
- dispatchEventAsync :: Typeable a => IO a -> Action ()
- asyncEventProvider :: (Dispatcher -> IO ()) -> Action ()
- asyncActionProvider :: ((Action () -> IO ()) -> IO ()) -> Action ()
- data Range a b = Range {}
- type CrdRange = Range Coord Coord
- type Coord = Coord' Int Int
- data Coord' a b = Coord {}
- newtype Offset = Offset Int
- data Span a b = Span a b
- overRow :: (Int -> Int) -> Coord -> Coord
- overCol :: (Int -> Int) -> Coord -> Coord
- coordRow :: forall a b a. Lens (Coord' a b) (Coord' a b) a a
- coordCol :: forall a b b. Lens (Coord' a b) (Coord' a b) b b
- overBoth :: Bifunctor f => (a -> b) -> f a a -> f b b
- combineSpans :: forall a. Monoid a => [Span CrdRange a] -> [(Coord, a)]
- asCoord :: YiString -> Iso' Offset Coord
- clampCoord :: YiString -> Coord -> Coord
- clampRange :: YiString -> CrdRange -> CrdRange
- rStart :: forall a b a. Lens (Range a b) (Range a b) a a
- rEnd :: forall a b b. Lens (Range a b) (Range a b) b b
- sizeOfR :: CrdRange -> Coord
- afterC :: Coord -> Lens' YiString YiString
- beforeC :: Coord -> Lens' YiString YiString
- moveRange :: Coord -> CrdRange -> CrdRange
- moveRangeByN :: Int -> CrdRange -> CrdRange
- moveCursorByN :: Int -> Coord -> Coord
- asText :: Iso' YiString Text
- asString :: Iso' YiString String
- asLines :: Iso' YiString [YiString]
- clamp :: Int -> Int -> Int -> Int
Editor Actions
This is a monad for performing actions against the editor.
You can register Actions to be run in response to events using onEveryTrigger
Within an Action you can:
- Use liftIO for IO
- Access/edit extensions that are stored globally, see
ext
- Embed any
Action
s exported other extensions - Embed buffer actions using
bufDo
orbuffersDo
- Add/Edit/Focus buffers and a few other Editor-level things, see the Rasa.Internal.Actions module.
This signals to the editor that you'd like to shutdown. The current events
will finish processing, then the onExit
event will be dispatched,
then the editor will exit.
Managing Buffers
newBuffer :: YiString -> Action BufRef Source #
This adds a new buffer with the given text, returning a reference to that buffer.
getBuffers :: Action [(BufRef, Buffer)] Source #
Returns an up-to-date list of all Buffer
s, returned values
are read-only; altering them has no effect on the actual stored buffers.
This function is useful for renderers.
getBuffer :: BufRef -> Action (Maybe Buffer) Source #
Returns the Buffer
for a BufRef if it still exists.
This is read-only; altering the buffer has no effect on the stored buffer.
This function is useful for renderers.
Working with Buffers
A buffer, holds the text in the buffer and any extension states that are set on the buffer.
class HasBuffer a where Source #
This allows creation of polymorphic lenses over any type which has access to a Buffer
This allows polymorphic lenses over anything that has access to an Editor context
Actions over Buffers
This is a monad for performing actions on a specific buffer.
You run BufAction
s by embedding them in a Action
via bufferDo
or
buffersDo
Within a BufAction you can:
- Use
liftAction
to run anAction
- Use liftIO for IO
- Access/Edit the buffer's text; some commands are available in Rasa.Internal.Actions.
- Access/edit buffer extensions; see
bufExt
- Embed and sequence
BufAction
s from other extensions
buffersDo_ :: BufAction a -> Action () Source #
Working with Text
overRange :: CrdRange -> (YiString -> YiString) -> BufAction () Source #
Runs function over given range of text
replaceRange :: CrdRange -> YiString -> BufAction () Source #
Replaces the text in the given range with the given text.
deleteRange :: CrdRange -> BufAction () Source #
Deletes the text in the given range from the buffer.
insertAt :: Coord -> YiString -> BufAction () Source #
Inserts text into the buffer at the given Coord
.
sizeOf :: YiString -> Coord Source #
Returns the number of rows and columns that a chunk of text spans as a Coord
Working with Extensions
Extension states for ALL the extensions installed are stored in the same
map keyed by their TypeRep
so if more than one extension
uses the same type then they'll conflict. This is easily solved by simply
using a newtype around any types which other extensions may use (your own
custom types don't need to be wrapped). For example if your extension stores
a counter as an Int, wrap it in your own custom Counter newtype when storing
it.
Because Extension states are stored by their TypeRep
, they must define an
instance of Typeable
, luckily GHC can derive this for you.
It is also required for all extension states to define an instance of
Default
, this is because accessing an extension which has not
yet been stored will result in the default value.
If there's no default value that makes sense for your type, you can define
a default of Nothing
and pattern match on its value when you
access it.
Extensions may store state persistently for later access or for other
extensions to access. Because Rasa can't possibly know the types of the
state that extensions will store it uses a clever workaround wherein
extension states are stored in a map of TypeRep
-> Ext
which is coerced into the proper type when it's extracted. The interface to
extract or alter a given extension is to use the ext
and bufExt
lenses.
Simply use them as though they were lenses to an object of your type and
it'll all work out.
Since it's polymorphic, if ghc can't figure out the type the result is supposed to be then you'll need to help it out. In practice you won't typically need to do this unless you're doing something complicated.
ext :: forall a e. (Show a, Typeable a, Default a, HasExts e) => Lens' e a Source #
This is a lens which will focus the extension state that matches the type inferred as the focal point. It's a little bit of magic, if you treat the focus as a member of your extension state it should just work out.
This lens falls back on the extension's Default
instance (when getting) if
nothing has yet been stored.
class HasBufExts s where Source #
Members of this class have access to buffer extensions. (Each Buffer
is a member of this class)
bufExt :: forall a s. (Show a, Typeable a, Default a, HasBufExts s) => Lens' s a Source #
bufExt
is a lens which will focus a given extension's state within a
buffer (within a BufAction
). The lens will automagically focus
the required extension by using type inference. It's a little bit of magic,
if you treat the focus as a member of your extension state it should just
work out.
This lens falls back on the extension's Default
instance (when getting) if
nothing has yet been stored.
Events
This event is dispatched in response to keyboard key presses. It contains both
the char that was pressed and any modifiers (Mod
) that where held when the key was pressed.
This represents each modifier key that could be pressed along with a key.
Dealing with events
data ListenerId Source #
An opaque reverence to a specific registered event-listener.
A ListenerId is used only to remove listeners later with removeListener
.
dispatchEvent :: Typeable a => a -> Action () Source #
Use this to dispatch an event of any type, any listeners which are listening for this event will be triggered with the provided event. Use this within an Action.
onEveryTrigger :: forall a b. Typeable a => (a -> Action b) -> Action ListenerId Source #
This registers an event listener, as long as the listener is well-typed similar to this:
MyEventType -> Action ()
then it will be triggered on all dispatched events of type MyEventType
.
It returns an ID which may be used with removeListener
to cancel the listener
onNextEvent :: forall a b. Typeable a => (a -> Action b) -> Action () Source #
This acts as onEveryTrigger
but listens only for the first event of a given type.
removeListener :: ListenerId -> Action () Source #
This removes a listener and prevents it from responding to any more events.
Built-in Event Listeners
onInit :: forall a. Action a -> Action () Source #
Registers an action to be performed during the Initialization phase.
This phase occurs exactly ONCE when the editor starts up. Though arbitrary actions may be performed in the configuration block; it's recommended to embed such actions in the onInit event listener so that all event listeners are registered before anything Actions occur.
beforeEveryEvent :: forall a. Action a -> Action ListenerId Source #
Registers an action to be performed BEFORE each event phase.
beforeEveryEvent_ :: forall a. Action a -> Action () Source #
beforeNextEvent :: forall a. Action a -> Action () Source #
Registers an action to be performed ONCE before only the NEXT event phase.
beforeEveryRender :: forall a. Action a -> Action ListenerId Source #
Registers an action to be performed BEFORE each render phase.
This is a good spot to add information useful to the renderer since all actions have been performed. Only cosmetic changes should occur during this phase.
beforeEveryRender_ :: forall a. Action a -> Action () Source #
beforeNextRender :: forall a. Action a -> Action () Source #
Registers an action to be performed ONCE before only the NEXT render phase.
onEveryRender :: forall a. Action a -> Action ListenerId Source #
Registers an action to be performed during each render phase.
This phase should only be used by extensions which actually render something.
onEveryRender_ :: forall a. Action a -> Action () Source #
onNextRender :: forall a. Action a -> Action () Source #
Registers an action to be performed ONCE before only the NEXT render phase.
This phase should only be used by extensions which actually render something.
afterEveryRender :: forall a. Action a -> Action ListenerId Source #
Registers an action to be performed AFTER each render phase.
This is useful for cleaning up extension state that was registered for the renderer, but needs to be cleared before the next iteration.
afterEveryRender_ :: forall a. Action a -> Action () Source #
afterNextRender :: forall a. Action a -> Action () Source #
Registers an action to be performed after the NEXT render phase.
onExit :: forall a. Action a -> Action () Source #
Registers an action to be performed during the exit phase.
This is only triggered exactly once when the editor is shutting down. It allows an opportunity to do clean-up, kill any processes you've started, or save any data before the editor terminates.
onBufAdded :: forall a. (BufRef -> Action a) -> Action ListenerId Source #
onBufTextChanged :: forall a. (CrdRange -> YiString -> Action a) -> Action ListenerId Source #
This is fired every time text in a buffer changes.
The range of text which was altered and the new value of that text are provided inside a BufTextChanged
event.
Working with Async Events/Actions
type Dispatcher = forall a. Typeable a => a -> IO () Source #
This is a type alias to make defining your event provider functions easier;
It represents the function your event provider function will be passed to allow dispatching
events. Using this type requires the Rank2Types
language pragma.
dispatchActionAsync :: IO (Action ()) -> Action () Source #
dispatchActionAsync allows you to perform a task asynchronously and then apply the
result. In dispatchActionAsync asyncAction
, asyncAction
is an IO which resolves to
an Action, note that the context in which the second action is executed is
NOT the same context in which dispatchActionAsync is called; it is likely that text and
other state have changed while the IO executed, so it's a good idea to check
(inside the applying Action) that things are in a good state before making
changes. Here's an example:
asyncCapitalize :: Action () asyncCapitalize = do txt <- focusDo $ use text -- We give dispatchActionAsync an IO which resolves in an action dispatchActionAsync $ ioPart txt ioPart :: Text -> IO (Action ()) ioPart txt = do result <- longAsyncronousCapitalizationProgram txt -- Note that this returns an Action, but it's still wrapped in IO return $ maybeApplyResult txt result maybeApplyResult :: Text -> Text -> Action () maybeApplyResult oldTxt capitalized = do -- We get the current buffer's text, which may have changed since we started newTxt <- focusDo (use text) if newTxt == oldTxt -- If the text is the same as it was, we can apply the transformation then focusDo (text .= capitalized) -- Otherwise we can choose to re-queue the whole action and try again -- Or we could just give up. else asyncCapitalize
dispatchEventAsync :: Typeable a => IO a -> Action () Source #
This function takes an IO which results in some Event, it runs the IO asynchronously and dispatches the event
asyncEventProvider :: (Dispatcher -> IO ()) -> Action () Source #
This allows long-running IO processes to provide Events to Rasa asyncronously.
Don't let the type signature confuse you; it's much simpler than it seems.
Let's break it down:
(
: Dispatcher
-> IO
())Dispatcher
is a type alias just to make defining your own functions easier;
Using Dispatcher
with asyncEventProvider requires the Rank2Types
language pragma.
This type as a whole represents a function which accepts a Dispatcher
and returns an IO
;
the dispatcher itself accepts data of ANY Typeable
type and emits it as an event (see the Rasa.Internal.Events).
When you call asyncEventProvider
you pass it a function which accepts a dispatch
function as an argument
and then calls it with various events within the resulting IO
.
Note that asyncEventProvider calls forkIO internally, so there's no need to do that yourself.
Here's a simple example which fires a Timer
event every second.
{-# language Rank2Types #-} data Timer = Timer myTimer :: Dispatcher -> IO () myTimer dispatch = forever $ dispatch Timer >> threadDelay 1000000 myAction :: Action () myAction = onInit $ asyncEventProvider myTimer
asyncActionProvider :: ((Action () -> IO ()) -> IO ()) -> Action () Source #
Don't let the type signature confuse you; it's much simpler than it seems.
The first argument is a function which takes an action provider; the action provider
will be passed a dispatch function which can be called as often as you like with Action ()
s.
When it is passed an Action
it forks off an IO to dispatch that Action
to the main event loop.
Note that the dispatch function calls forkIO on its own; so there's no need for you to do so.
Use this function when you have some long-running process which dispatches multiple Action
s.
Ranges
This represents a range between two coordinates (Coord
)
type CrdRange = Range Coord Coord Source #
A type alias to Range'
which specializes the types to Coord
s.
(Coord Row Column) represents a char in a block of text. (zero indexed) e.g. Coord 0 0 is the first character in the text, Coord 2 1 is the second character of the third row
An Offset
represents an exact position in a file as a number of characters from the start.
A span which maps a piece of Monoidal data over a range.
Span a b |
overBoth :: Bifunctor f => (a -> b) -> f a a -> f b b Source #
Applies a function over both functors in any Bifunctor
.
combineSpans :: forall a. Monoid a => [Span CrdRange a] -> [(Coord, a)] Source #
Combines a list of spans containing some monoidal data into a list of offsets with with the data that applies from each Offset forwards.
clampCoord :: YiString -> Coord -> Coord Source #
This will restrict a given Coord
to a valid one which lies within the given text.
clampRange :: YiString -> CrdRange -> CrdRange Source #
This will restrict a given Range
to a valid one which lies within the given text.