• Iavor S. Diatchki's avatar
    Add a provenance field to universal coercions. · 1d4e94d1
    Iavor S. Diatchki authored
    Universal coercions allow casting between arbitrary types, so it is a
    good idea to keep track where they came from, which now we can do by
    using the provenance field in `UnivCo`.
    This is also handy for type-checker plugins that provide functionality
    beyond what's expressible by GHC's standard coercions:  such plugins
    can generate universal coercions, but they should still tag them,
    so that if something goes wrong we can link the casts to the plugin.
TcIface.hs 59.4 KB