Fix merges (#340)

* Augment changelog, add profunctor bounds 
* Document commented instance signature

Author: oliver-batchelor

ChangeLog.md

@@ -3,14 +3,21 @@
 ## 0.6.2.1
 
 * Generalize `fan` to `fanG` to take a `DMap` with non-`Identity`
-  values.
+  functor:
+    * `fan` to `fanG`
+    * `EventSelectorG` for `fanG` result selector.
+
+* Reduce the amount of unsafeCoerce in coercing newtypes under Event/Dynamic/Behavior.
+    * Add fused ReaderIO for the purpose of coercion (ReaderT's third argument has nominal role preventing automated coerce)
+    * Add incrementalCoercion/coerceIncremental to go with dynamicCoercion/coerceDynamic
 
 * Generalize merging functions:
   `merge` to `mergeG`, 
   `mergeIncremental` to `mergeIncrementalG`, 
-  `distributeDMapOverDynPure` to `distributeDMapOverDynPureG`,
   `mergeIncrementalWithMove` to `mergeIncrementalWithMoveG`.  
 
+* Generalize distribute function:
+    `distributeDMapOverDynPure` to `distributeDMapOverDynPureG`,
 
 ## 0.6.2.0
 

default.nix

@@ -22,6 +22,7 @@ mkDerivation {
     base bifunctors containers deepseq dependent-map dependent-sum
     mtl ref-tf split transformers data-default
     random time unbounded-delays monoidal-containers witherable
+    profunctors
   ] ++ (if ghc.isGhcjs or false then [
     ghcjs-base
   ] else []) ++ (if !useTemplateHaskell then [] else [

reflex.cabal

@@ -49,7 +49,7 @@ library
     data-default >= 0.5 && < 0.8,
     dependent-map >= 0.3 && < 0.4,
     exception-transformers == 0.4.*,
-    profunctors,
+    profunctors >= 5.0 && < 6.0,
     lens >= 4.7 && < 5,
     monad-control >= 1.0.1 && < 1.1,
     monoidal-containers >= 0.4 && < 0.6,

src/Reflex/Pure.hs

@@ -93,7 +93,8 @@ instance (Enum t, HasTrie t, Ord t) => Reflex (Pure t) where
        then Nothing
        else Just currentOccurrences
 
-  -- fanG :: GCompare k => Event (Pure t) (DMap k v) -> EventSelectorG (Pure t) k v
+--  The instance signature doeesn't compile, leave commented for documentation
+--  fanG :: GCompare k => Event (Pure t) (DMap k v) -> EventSelectorG (Pure t) k v
   fanG e = EventSelectorG $ \k -> Event $ \t -> unEvent e t >>= DMap.lookup k
 
   switch :: Behavior (Pure t) (Event (Pure t) a) -> Event (Pure t) a