recover commens deleted by ormolu, add some instance sigs

src/Sound/Tidal/Pattern.hs

@@ -4,6 +4,7 @@
 {-# LANGUAGE DeriveGeneric #-}
 {-# LANGUAGE FlexibleInstances #-}
 {-# LANGUAGE GeneralizedNewtypeDeriving #-}
+{-# LANGUAGE InstanceSigs #-}
 {-# OPTIONS_GHC -fno-warn-orphans #-}
 
 {-
@@ -92,6 +93,8 @@ type ControlPattern = Pattern ValueMap
 -- * Applicative and friends
 
 instance Applicative Pattern where
+  -- Repeat the given value once per cycle, forever
+  pure :: a -> Pattern a
   pure v = Pattern q (Just 1) (Just v)
     where
       q (State a _) =
@@ -104,6 +107,31 @@ instance Applicative Pattern where
                 v
           )
           $ cycleArcsInArc a
+
+  -- In each of @a <*> b@, @a <* b@ and @a *> b@
+  -- (using the definitions from this module, not the Prelude),
+  -- the time structure of the result
+  -- depends on the structures of both @a@ and @b@.
+  -- They all result in @Event@s with identical @part@s and @value@s.
+  -- However, their @whole@s are different.
+  --
+  -- For instance, @listToPat [(+1), (+2)] <*> "0 10 100"@
+  -- gives the following 4-@Event@ cycle:
+  -- > (0>⅓)|1
+  -- > (⅓>½)|11
+  -- > (½>⅔)|12
+  -- > (⅔>1)|102
+  -- If we use @<*@ instead, we get this:
+  -- > (0>⅓)-½|1
+  -- > 0-(⅓>½)|11
+  -- > (½>⅔)-1|12
+  -- > ½-(⅔>1)|102
+  -- And if we use @*>@, we get this:
+  -- >   (0>⅓)|1
+  -- > (⅓>½)-⅔|11
+  -- > ⅓-(½>⅔)|12
+  -- >   (⅔>1)|102
+  (<*>) :: Pattern (a -> b) -> Pattern a -> Pattern b
   (<*>) a b = (applyPatToPatBoth a b) {tactus = lcmr <$> tactus a <*> tactus b}
 
 -- | Like @<*>@, but the "wholes" come from the left