#9815: Runtime error with RecordWildCards and a non-record constructor -------------------------------------+------------------------------------- Reporter: akio | Owner: Type: feature request | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.8.3 Keywords: RecordWildCards, | Operating System: warning | Unknown/Multiple Architecture: Unknown/Multiple | Type of failure: GHC Difficulty: Unknown | accepts invalid program Blocked By: | Test Case: Related Tickets: | Blocking: | Differential Revisions: -------------------------------------+------------------------------------- The following program is accepted with no warning, and crashes at runtime with an error: {{{#!hs {-# LANGUAGE RecordWildCards #-} newtype N = N Int deriving (Show) main = print N{..} }}} {{{ % runghc wildcards.hs wildcards.hs: wildcards.hs:4:14-18: Missing field in record construction }}} I find this behavior surprising. Would it be better to either disallow it or have `-fwarn-missing-fields` warn it? -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/9815 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler