diff options
Diffstat (limited to 'compiler/GHC/Tc/Deriv')
| -rw-r--r-- | compiler/GHC/Tc/Deriv/Generate.hs | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/compiler/GHC/Tc/Deriv/Generate.hs b/compiler/GHC/Tc/Deriv/Generate.hs index 9a76c82b8f..b8678e4344 100644 --- a/compiler/GHC/Tc/Deriv/Generate.hs +++ b/compiler/GHC/Tc/Deriv/Generate.hs @@ -1875,9 +1875,9 @@ of the method. For example, recall: join In the example above, it is imperative that the `a` in the instance signature -for `join` scope over the body of `join` by way of ScopedTypeVariables. -This might sound obvious, but note that in gen_Newtype_binds, which is -responsible for generating the code above, the type in `join`'s instance +for `join` scope over the body of `join` by way of ExtendedForallScope (implied +by ScopedTypeVariables). This might sound obvious, but note that in gen_Newtype_binds, +which is responsible for generating the code above, the type in `join`'s instance signature is given as a Core type, whereas gen_Newtype_binds will eventually produce HsBinds (i.e., source Haskell) that is renamed and typechecked. We must ensure that `a` is in scope over the body of `join` during renaming |