Clean up Nullable and Null

Author: cknitt

src/Core__Null.res

@@ -2,7 +2,7 @@ type t<'a> = Js.Null.t<'a>
 
 external asNullable: t<'a> => Core__Nullable.t<'a> = "%identity"
 
-external empty: t<'a> = "#null"
+external null: t<'a> = "#null"
 
 external make: 'a => t<'a> = "%identity"
 
@@ -11,5 +11,5 @@ external toOption: t<'a> => option<'a> = "#null_to_opt"
 let fromOption: option<'a> => t<'a> = option =>
   switch option {
   | Some(x) => make(x)
-  | None => empty
+  | None => null
   }

src/Core__Nullable.res

@@ -4,14 +4,12 @@ external null: t<'a> = "#null"
 
 external undefined: t<'a> = "#undefined"
 
-external empty: t<'a> = "#undefined"
-
 external make: 'a => t<'a> = "%identity"
 
 external toOption: t<'a> => option<'a> = "#nullable_to_opt"
 
 let fromOption: option<'a> => t<'a> = option =>
   switch option {
   | Some(x) => make(x)
-  | None => empty
+  | None => undefined
   }