Wrong warning by -Wincomplete-patterns
Wrong warning occur where I use -Wincomplete-patterns with OverloadedLists and TypeFamilies.
{-# LANGUAGE OverloadedLists #-}
{-# LANGUAGE TypeFamilies #-}
{-# OPTIONS_GHC -Wall -fno-warn-tabs #-}
class Foo f where
type It f
foo :: [It f] -> f
data List a = Empty | a :! List a deriving Show
instance Foo (List a) where
type It (List a) = a
foo [] = Empty
foo (x : xs) = x :! foo xsPattern match(es) are non-exhaustive In an equation for `foo': Patterns not matched: []
Trac metadata
| Trac field | Value |
|---|---|
| Version | 8.2.1 |
| Type | Bug |
| TypeOfFailure | OtherFailure |
| Priority | low |
| Resolution | Unresolved |
| Component | Compiler |
| Test case | |
| Differential revisions | |
| BlockedBy | |
| Related | |
| Blocking | |
| CC | |
| Operating system | |
| Architecture |