• simonpj@microsoft.com's avatar
    isDataTyCon should be False for all type families, even data type families · 71d2bf92
    simonpj@microsoft.com authored
    isDataTyCon advertises that it's true of "data types that are
    definitely represented by heap-allocated constructors.  These are
    srcutinised by Core-level @case@ expressions, and they get info tables
    allocated for them."
    Type-family TyCons never have this property, not even data type families.
    It's the *instance* TyCons that do.
    I hope that this change does not break anything that somehow relied
    on the old (wrong) semantics.