Qualified names can not be used as type constructor arguments in case statements.

[lachenmayer]

Bar.elm:

module Bar where

type Action = Baz | Qux

Foo.elm:

module Foo where

import Bar exposing (Action(Qux))

type Action = NoOp | BarAction Bar.Action

foo : Action -> Int
foo action =
  case action of
    NoOp -> 0
    BarAction Bar.Baz -> 1 -- ERROR!
    BarAction Qux -> 2 -- works

faa : Bar.Action -> Int
faa action =
  case action of
    Bar.Baz -> 0 -- works
    Bar.Qux -> 1 -- works

Compilation result:

Error in Foo.elm:

Parse error at (line 11, column 18):
unexpected "."
expecting whitespace, a newline, pattern, cons operator '::' or arrow (->)

Expected behaviour:
BarAction Bar.Baz should match without error.

[sindikat]

Qualified imports are also a problem in record updates.

[evancz]

Should be fixed in 0.17

[evancz]

Thanks for the report!