• Alan Zimmerman's avatar
    ApiAnnotations : Nested forall loses forall annotation · 81030ede
    Alan Zimmerman authored
    When parsing
    
        {-# LANGUAGE ScopedTypeVariables #-}
    
        extremumNewton :: forall tag. forall tag1.
                           tag -> tag1 -> Int
        extremumNewton = undefined
    
    The parser attaches an AnnForall to the second forall, which appears as
    a nested HsForAllTy.
    
    Somewhere this nesting is flattened, and the tyvarbndrs are collapsed
    into a single HsForAllTy. In this process the second AnnForAll loses its
    anchor in the AST.
    
    Reviewed By: austin
    
    Differential Revision: https://phabricator.haskell.org/D833
    
    GHC Trac Issues: #10278
    81030ede
T10278.stdout 2.86 KB