Fix parser for expressions with nested annotations (#1527)

Gabriella439 · mergify[bot] · commit 008a9c3e3709 · 2019-11-11T20:43:29.000Z
Fixes #1467 We now no longer replace an annotation if one was already present
diff --git a/dhall/src/Dhall/Parser/Expression.hs b/dhall/src/Dhall/Parser/Expression.hs
@@ -273,11 +273,11 @@ parsers embedded = Parsers {..}
                     nonemptyWhitespace
                     b <- expression
                     case shallowDenote a of
-                        ListLit _ [] ->
+                        ListLit Nothing [] ->
                             return (ListLit (Just b) [])
-                        Merge c d _ ->
+                        Merge c d Nothing ->
                             return (Merge c d (Just b))
-                        ToMap c _ ->
+                        ToMap c Nothing ->
                             return (ToMap c (Just b))
                         _ -> return (Annot a b)
 
diff --git a/dhall/tests/format/nestedAnnotationA.dhall b/dhall/tests/format/nestedAnnotationA.dhall
@@ -0,0 +1 @@
+([] : a) : b
diff --git a/dhall/tests/format/nestedAnnotationB.dhall b/dhall/tests/format/nestedAnnotationB.dhall
@@ -0,0 +1 @@
+([] : a) : b
