Improve coding style

Co-authored-by: Pablo Lamela  <pablo.lamela@iohk.io>

marlowe-playground-client/src/Contrib/Data/Unfoldable.purs

@@ -21,7 +21,7 @@ move
   -> f a
   -> Maybe (g a)
 move { from, to } foldable = do
-  when (to > length foldable)
+  when (to < 0 || to > length foldable)
     Nothing
   let
     foldStep idx elem acc
@@ -30,17 +30,11 @@ move { from, to } foldable = do
 
     { elem, items } = foldrWithIndex foldStep { elem: Nothing, items: List.Nil }
       foldable
-  let
-    unfoldStep seed@{ idx, elem, items } = do
-      let
-        idx' = idx + 1
-
-        result
-          | idx == to = Just (elem /\ seed { idx = idx' })
-          | otherwise = do
+    unfoldStep seed@{ idx, elem, items }
+      | idx == to = Just (elem /\ seed { idx = idx + 1 })
+      | otherwise = do
               { head, tail } <- List.uncons items
-              Just (head /\ seed { idx = idx', items = tail })
-      result
+              Just (head /\ seed { idx = idx + 1, items = tail })
   -- | There is no UnfoldableWithIndex unfortunatelly... yet:
   -- | https://github.com/purescript/purescript-foldable-traversable/issues/84
   -- | so we have to carry the index ourselves.

marlowe-playground-client/src/Contrib/Halogen/Components/Sortable.purs

@@ -31,8 +31,8 @@ nextVersion :: OrderingVersion -> OrderingVersion
 nextVersion (OrderingVersion i) = OrderingVersion (i + 1)
 
 -- | We have to keep ordering version because sorting can trigger
--- | reordering which assynchronously is repainted. If in between
--- | we trigger some other reordering it is going to be inconsisten
+-- | reordering which asynchronously is repainted. If in between
+-- | we trigger some other reordering it is going to be inconsistent
 -- | with the new one so we have to ignore all events till everything is
 -- | repainted
 type State