varying 0.1.0.3 → 0.1.1.0

raw patch · 3 files changed

+31/−4 lines, 3 files

Files

• src/Control/Varying/Core.hs +8/−2
• src/Control/Varying/Event.hs +22/−1
• varying.cabal +1/−1

@@ -37,7 +37,8 @@     testVar_,     testWhile_,     vtrace,-    vstrace+    vstrace,+    vftrace, ) where  import Prelude hiding (id, (.))@@ -142,7 +143,12 @@ -- | Trace the sample value of a 'Var' with a prefix and pass the sample along -- as output. This is very useful for debugging graphs of 'Var's. vstrace :: (Applicative a, Show b) => String -> Var a b b-vstrace s = var $ \b -> trace (s ++ show b) b+vstrace s = vftrace ((s ++) . show)++-- | Trace the sample value after being run through a "show" function.+-- This is very useful for debugging graphs of 'Var's.+vftrace :: Applicative a => (b -> String) -> Var a b b+vftrace f = var $ \b -> trace (f b) b  -- | A utility function for testing 'Var's that don't require input. Runs -- a 'Var' printing each sample until the given predicate fails.

@@ -34,6 +34,7 @@     toEvent,     -- * Using event streams     collect,+    collectWith,     hold,     holdWith,     startingWith,@@ -55,6 +56,8 @@     andThenWith,     andThenE,     switchByMode,+    onlyWhen,+    onlyWhenE,     -- * Combining event streams     combineWith,     combine@@ -187,7 +190,8 @@                                         Event a' -> f a' b                           in return (b', Var $ \a' -> collect' b' a') --- | Collect all produced values into a list.+-- | Collect all produced values into a list. The latest event value will+-- be at the head of the list. collect :: Monad m => Var m (Event a) [a] collect = collectWith (:) @@ -347,6 +351,23 @@                       where vOf eb = case eb of                                          NoEvent -> v                                          Event b -> f b++-- | Produce event values only when the input value passes the predicate.+-- Maintains state when 'cold'.+onlyWhen :: Monad m => Var m a b -> (a -> Bool) -> Var m a (Event b)+onlyWhen v f = v `onlyWhenE` hot+    where hot = var id ~> onWhen f++-- | Produce event values from the first signal only when an event is+-- produced by the second signal.+-- Maintains state when 'cold'.+onlyWhenE :: Monad m => Var m a b -> Var m a (Event c) -> Var m a (Event b)+onlyWhenE v hot = Var $ \a -> do+    (e, hot') <- runVar hot a+    if isEvent e+    then do (b, v') <- runVar v a+            return (Event b, onlyWhenE v' hot')+    else return (NoEvent, onlyWhenE v hot') -------------------------------------------------------------------------------- -- Combining event streams --------------------------------------------------------------------------------

@@ -10,7 +10,7 @@ -- PVP summary:      +-+------- breaking API changes --                   | | +----- non-breaking API additions --                   | | | +--- code changes with no API change-version:             0.1.0.3+version:             0.1.1.0  -- A short (one-line) description of the package. synopsis:            Automaton based varying values, event streams and tweening.