[Git][ghc/ghc][wip/exception-propagate] 8 commits: Fix typo in Prelude doc for (>>=)

Mon Sep 30 09:44:14 UTC 2024

Rodrigo Mesquita pushed to branch wip/exception-propagate at Glasgow Haskell Compiler / GHC

Commits:
9ffd6163 by Leo at 2024-09-27T16:26:01+05:30
Fix typo in Prelude doc for (>>=)

Fix a minor typo ("equivialent" instead of "equivalent") in the documentation for (>>=) in the prelude.

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5745dbd3 by Vladislav Zavialov at 2024-09-27T16:26:52+05:30
Wildcard binders in type declarations (#23501)

Add support for wildcard binders in type declarations:

	type Const a b = a   -- BEFORE: the `b` had to be named
	                     --         even if unused on the RHS

	type Const a _ = a   -- AFTER: the compiler accepts
	                     --        a wildcard binder `_`

The new feature is part of GHC Proposal #425 "Invisible binders
in type declarations", and more specifically its amendment #641.

Just like a named binder, a wildcard binder `_` may be:

	* plain:      _
	* kinded:    (_ :: k -> Type)
	* invisible, plain:  @_
	* invisible, kinded: @(_ :: k -> Type)

Those new forms of binders are allowed to occur on the LHSs of
data, newtype, type, class, and type/data family declarations:

	data D _ = ...
	newtype N _ = ...
	type T _ = ...
	class C _ where ...
	type family F _
	data family DF _

(Test case: testsuite/tests/typecheck/should_compile/T23501a.hs)

However, we choose to reject them in forall telescopes and
type family result variable binders (the latter being part
of the TypeFamilyDependencies extension):

	type family Fd a = _    -- disallowed  (WildcardBndrInTyFamResultVar)
	fn :: forall _. Int     -- disallowed  (WildcardBndrInForallTelescope)

(Test case: testsuite/tests/rename/should_fail/T23501_fail.hs)

See the new Notes:
	* Note [Type variable binders]
	* Note [Wildcard binders in disallowed contexts]

To accommodate the new forms of binders, HsTyVarBndr was changed
as follows (demonstrated without x-fields for clarity)

	-- BEFORE (ignoring x-fields and locations)
	data HsTyVarBndr flag
	  = UserTyVar   flag Name
	  | KindedTyVar flag Name HsKind

	-- AFTER (ignoring x-fields and locations)
	data HsTyVarBndr flag = HsTvb flag HsBndrVar HsBndrKind
	data HsBndrVar  = HsBndrVar Name | HsBndrWildCard
	data HsBndrKind = HsBndrNoKind | HsBndrKind LHsKind

The rest of the patch is downstream from this change.

To avoid a breaking change to the TH AST, we generate fresh
names to replace wildcard binders instead of adding a dedicated
representation for them (as discussed in #641).

And to put a cherry on top of the cake, we now allow wildcards in
kind-polymorphic type variable binders in constructor patterns,
see Note [Type patterns: binders and unifiers] and the tyPatToBndr
function in GHC.Tc.Gen.HsType; example:

	fn (MkT @(_ :: forall k. k -> Type) _ _) = ...

(Test case: testsuite/tests/typecheck/should_compile/T23501b.hs)

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ff2bdca2 by Matthew Pickering at 2024-09-27T16:27:08+05:30
ci: Push perf notes from wasm jobs

It was observed in #25299 that we were failing to push performance
numbers from the wasm jobs.

In future we might want to remove this ad-hoc check but for now it's
easier to add another special case.

Towards #25299

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4c76f75c by Zubin Duggal at 2024-09-27T16:44:00+05:30
Bump GHC version to 9.12

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e4ac1b0d by Zubin Duggal at 2024-09-27T19:12:24+05:30
Bump GHC version to 9.13

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7d6945cd by Matthew Pickering at 2024-09-30T10:31:29+01:00
Fix toException method for ExceptionWithContext

Fixes #25235

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1b121165 by Matthew Pickering at 2024-09-30T10:43:34+01:00
Exception rethrowing

Basic changes:

* Change `catch` function to propagate exceptions using the
  WhileHandling mechanism.
* Introduce `catchNoPropagate`, which does the same as before, but
  passes an exception which can be rethrown.
* Introduce `rethrowIO` combinator, which rethrows an exception with a
  context and doesn't add a new backtrace.
* Introduce `tryWithContext` for a variant of `try` which can rethrow
  the exception with it's original context.
* onException is modified to rethrow the original error rather than
  creating a new callstack.
* Functions which rethrow in GHC.Internal.IO.Handle.FD,
  GHC.Internal.IO.Handle.Internals, GHC.Internal.IO.Handle.Text, and
  GHC.Internal.System.IO.Error are modified to not add a new callstack.

Implements CLC proposal#202 <https://github.com/haskell/core-libraries-committee/issues/202>

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f9591422 by Rodrigo Mesquita at 2024-09-30T10:43:34+01:00
Add test for #25300

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30 changed files:

- .gitlab/ci.sh
- compiler/GHC/Hs/Decls.hs
- compiler/GHC/Hs/Instances.hs
- compiler/GHC/Hs/Type.hs
- compiler/GHC/HsToCore/Quote.hs
- compiler/GHC/Iface/Ext/Ast.hs
- compiler/GHC/Parser.y
- compiler/GHC/Parser/PostProcess.hs
- compiler/GHC/Rename/HsType.hs
- compiler/GHC/Rename/Module.hs
- compiler/GHC/Tc/Errors/Ppr.hs
- compiler/GHC/Tc/Errors/Types.hs
- compiler/GHC/Tc/Gen/HsType.hs
- compiler/GHC/Tc/Gen/Sig.hs
- compiler/GHC/Tc/TyCl.hs
- compiler/GHC/ThToHs.hs
- compiler/GHC/Types/Error/Codes.hs
- compiler/Language/Haskell/Syntax/Extension.hs
- compiler/Language/Haskell/Syntax/Type.hs
- configure.ac
- − docs/users_guide/9.12.1-notes.rst
- + docs/users_guide/9.14.1-notes.rst
- docs/users_guide/exts/type_abstractions.rst
- libraries/base/changelog.md
- libraries/base/src/Control/Exception.hs
- libraries/base/tests/IO/T21336/T21336b.stderr
- libraries/base/tests/IO/T4808.stderr
- libraries/base/tests/IO/mkdirExists.stderr
- libraries/base/tests/IO/openFile002.stderr
- libraries/base/tests/IO/withBinaryFile001.stderr

The diff was not included because it is too large.

View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/bc17852db59b8fc4f2f505610e9a0aaf92234e29...f959142263a0fccbc0b7b9328104a60283de9e49

-- 
View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/bc17852db59b8fc4f2f505610e9a0aaf92234e29...f959142263a0fccbc0b7b9328104a60283de9e49
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