When deriving Functor, Foldable, Traversable, we need only look at the
way that the last type argument is treated.  It's fine for there to
be existentials etc, provided they don't affect the last type argument.

See Note [Check that the type variable is truly universal] in TcDeriv.

Thanks to George Colpitts for helping us remember this!

Signed-off-by: Austin Seipp <austin@well-typed.com>

Notably, GND is now usable with Safe Haskell. Also, Coercible now is in
Data.Coerce canonically, and we added some more instances.

Signed-off-by: Austin Seipp <austin@well-typed.com>

See documentation for details.

Signed-off-by: Austin Seipp <austin@well-typed.com>

add more information about the nature of support of prefetch primops on none x86/AMD64 -fasm platforms (and -fvia)
to the 7.8 release notes

Signed-off-by: Austin Seipp <austin@well-typed.com>

Suggested by Gabor Greif on ghc-devs

type holes -> typed holes, reorder, minor changes

Signed-off-by: Austin Seipp <austin@well-typed.com>

Signed-off-by: Austin Seipp <austin@well-typed.com>

Signed-off-by: Austin Seipp <austin@well-typed.com>

The binutils linker on ARM emits unnecessary R_ARM_COPY relocations
which breaks tables-next-to-code in dynamically linked modules. This
check should be more selective but there is currently no released
version where this bug is fixed.  See
https://sourceware.org/bugzilla/show_bug.cgi?id=16177 and
https://ghc.haskell.org/trac/ghc/ticket/4210#comment:29

 for details.

Signed-off-by: Austin Seipp <austin@well-typed.com>

Signed-off-by: Austin Seipp <austin@well-typed.com>

This fixes #7134

Signed-off-by: Austin Seipp <austin@well-typed.com>

This change seems worth mentioning

Signed-off-by: Austin Seipp <austin@well-typed.com>

Signed-off-by: Austin Seipp <austin@well-typed.com>

Signed-off-by: Austin Seipp <austin@well-typed.com>

Signed-off-by: Austin Seipp <austin@well-typed.com>

Signed-off-by: Austin Seipp <austin@well-typed.com>

Signed-off-by: Austin Seipp <austin@well-typed.com>

In particular, spell out the current dynamic situation, clean up the
FIXMEs and xrefs, and don't forget to mention InterruptibleFFI.

Signed-off-by: Austin Seipp <austin@well-typed.com>

Signed-off-by: Edward Z. Yang <ezyang@cs.stanford.edu>

Signed-off-by: Austin Seipp <austin@well-typed.com>

After some discussion on ghc-devs@ and elsewhere, it seemed favorable to
make this change as type holes don't let any invalid programs though,
they merely change what the compiler reports in case of certain errors
(namely unbound occurrences, or _ appearing on a LHS.)

Now, the warning mechanism is controlled by -f[no-]warn-type-errors,
just like any other regular warning. Again, on by default.

The documentation and tests have been updated accordingly.

Signed-off-by: Austin Seipp <austin@well-typed.com>

This applies the changes in commit
a924debc to the PDF file.

Richard, you may want to regenerate the PDF
as I get

! LaTeX Error: File `stmaryrd.sty' not found.

with my setup and do not want to mess things up.

Also for me ?? appear twice on top of the page 13
and I have tp 'rm core-spec.pdf; make' to get it
right.

This change is just some documentation around ignoring the context
of an enclosing instance when processing `deriving` clauses of an
associated data instance.

We do *not* propagate kind information from an instance declaration's
members back into the instance head.