#14133: COMPLETE pragmas seem to be ignored when using view patterns -------------------------------------+------------------------------------- Reporter: jle | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.2.1 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Incorrect | Unknown/Multiple error/warning at compile-time | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Description changed by jle: Old description:
{{{#!hs {-# LANGUAGE ViewPatterns #-} {-# LANGUAGE PatternSynonyms #-}
pattern I :: Int -> Int pattern I x <- (id -> x) {-# COMPLETE I #-}
foo :: Int -> Int foo (I x) = x + 3
bar :: Int -> Int bar (id->I x) = x + 3
main :: IO () main = return () }}}
Raises a warning for `bar`:
{{{ Bug.hs:12:1: warning: [-Wincomplete-patterns] Pattern match(es) are non-exhaustive In an equation for 'bar': Patterns not matched: _ | 12 | bar (id->(I x)) = x + 3 | ^^^^^^^^^^^^^^^^^^^^^^^ }}}
but not for `foo`.
New description: {{{#!hs {-# LANGUAGE ViewPatterns #-} {-# LANGUAGE PatternSynonyms #-} pattern I :: Int -> Int pattern I x <- (id -> x) {-# COMPLETE I #-} foo :: Int -> Int foo (I x) = x + 3 bar :: Int -> Int bar (id->I x) = x + 3 main :: IO () main = return () }}} Raises a warning for `bar`: {{{ Bug.hs:12:1: warning: [-Wincomplete-patterns] Pattern match(es) are non-exhaustive In an equation for 'bar': Patterns not matched: _ | 12 | bar (id->I x) = x + 3 | ^^^^^^^^^^^^^^^^^^^^^^^ }}} but not for `foo`. -- -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14133#comment:1 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler