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Confusing error message with RecordWildCards

    • Closed Issue created by trevor @trac-trevor

    When using the RecordWildCards extension, a confusing error message is given when the constructor name is invalid. For example, this module:

    {-# LANGUAGE RecordWildCards #-}

module Test where

data T = T { x :: Int }

f :: T -> Int
f T' { .. } = x + 1

    yields two error messages. The first is about the constructor T' not being in scope, and the second is a confusing message about how `..' is not valid in a record pattern:

    {{{ GHCi, version 7.8.3: http://www.haskell.org/ghc/ :? for help Loading package ghc-prim ... linking ... done. Loading package integer-gmp ... linking ... done. Loading package base ... linking ... done. [1 of 1] Compiling Test ( Test.hs, interpreted )

    Test.hs:8:3: Not in scope: data constructor ‘T'’ Perhaps you meant ‘T’ (line 5)

    Test.hs:8:3: You cannot use `..' in a record pattern Failed, modules loaded: none. }}}

    It seems like the second error should be left out in this case, as it's enough to report that the name isn't in scope.

    Trac metadata
    Trac field Value
    Version 7.8.3
    Type Bug
    TypeOfFailure OtherFailure
    Priority normal
    Resolution Unresolved
    Component Compiler
    Test case
    Differential revisions
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    Operating system
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