Vladislav Zavialov authored 1 year ago and Marge Bot committed 1 year ago

Numerous tests make use of CUSKs (complete user-supplied kinds),
a legacy feature scheduled for deprecation. In order to proceed
with the said deprecation, the tests have been updated to use SAKS
instead (standalone kind signatures).

This also allows us to remove the Haskell2010 language pragmas that
were added in 115cd3c8 to work around the lack of CUSKs in GHC2021.

This patch implements @k-binders introduced in GHC Proposal #425
and guarded behind the TypeAbstractions extension:

	type D :: forall k j. k -> j -> Type
	data D @k @j a b = ...
	       ^^ ^^

To represent the new syntax, we modify LHsQTyVars as follows:

	-  hsq_explicit :: [LHsTyVarBndr () pass]
	+  hsq_explicit :: [LHsTyVarBndr (HsBndrVis pass) pass]

HsBndrVis is a new data type that records the distinction between
type variable binders written with and without the @ sign:

	data HsBndrVis pass
	  = HsBndrRequired
	  | HsBndrInvisible (LHsToken "@" pass)

The rest of the patch updates GHC, template-haskell, and haddock
to handle the new syntax.

Parser:
  The PsErrUnexpectedTypeAppInDecl error message is removed.
  The syntax it used to reject is now permitted.

Renamer:
  The @ sign does not affect the scope of a binder, so the changes to
  the renamer are minimal.  See rnLHsTyVarBndrVisFlag.

Type checker:
  There are three code paths that were updated to deal with the newly
  introduced invisible type variable binders:

    1. checking SAKS: see kcCheckDeclHeader_sig, matchUpSigWithDecl
    2. checking CUSK: see kcCheckDeclHeader_cusk
    3. inference: see kcInferDeclHeader, rejectInvisibleBinders

  Helper functions bindExplicitTKBndrs_Q_Skol and bindExplicitTKBndrs_Q_Tv
  are generalized to work with HsBndrVis.

Updates the haddock submodule.

Metric Increase:
    MultiLayerModulesTH_OneShot

Co-authored-by: Simon Peyton Jones <simon.peytonjones@gmail.com>

Gert-Jan Bottu authored 5 years ago and Marge Bot committed 4 years ago

Implementation for Ticket #16393.
Explicit specificity allows users to manually create inferred type variables,
by marking them with braces.
This way, the user determines which variables can be instantiated through
visible type application.

The additional syntax is included in the parser, allowing users to write
braces in type variable binders (type signatures, data constructors etc).
This information is passed along through the renamer and verified in the
type checker.
The AST for type variable binders, data constructors, pattern synonyms,
partial signatures and Template Haskell has been updated to include the
specificity of type variables.

Minor notes:
- Bumps haddock submodule
- Disables pattern match checking in GHC.Iface.Type with GHC 8.8

Richard Eisenberg authored 5 years ago and Marge Bot committed 5 years ago

Test case: indexed-types/should_fail/T13571

Summary:
This patch implements visible kind application (GHC Proposal 15/#12045), as well as #15360 and #15362.
It also refactors unnamed wildcard handling, and requires that type equations in type families in Template Haskell be
written with full type on lhs. PartialTypeSignatures are on and warnings are off automatically with visible kind
application, just like in term-level.

There are a few remaining issues with this patch, as documented in
ticket #16082.

Includes a submodule update for Haddock.

Test Plan: Tests T12045a/b/c/TH1/TH2, T15362, T15592a

Reviewers: simonpj, goldfire, bgamari, alanz, RyanGlScott, Iceland_jack

Subscribers: ningning, Iceland_jack, RyanGlScott, int-index, rwbarton, mpickering, carter

GHC Trac Issues: `#12045`, `#15362`, `#15592`, `#15788`, `#15793`, `#15795`, `#15797`, `#15799`, `#15801`, `#15807`, `#15816`

Differential Revision: https://phabricator.haskell.org/D5229

Allow the user to explicitly bind type/kind variables in type and data
family instances (including associated instances), closed type family
equations, and RULES pragmas. Follows the specification of GHC
Proposal 0007, also fixes #2600. Advised by Richard Eisenberg.

This modifies the Template Haskell AST -- old code may break!

Other Changes:
- convert HsRule to a record
- make rnHsSigWcType more general
- add repMaybe to DsMeta

Includes submodule update for Haddock.

Test Plan: validate

Reviewers: goldfire, bgamari, alanz

Subscribers: simonpj, RyanGlScott, goldfire, rwbarton,
             thomie, mpickering, carter

GHC Trac Issues: #2600, #14268

Differential Revision: https://phabricator.haskell.org/D4894

johnleo authored 9 years ago and Ben Gamari committed 9 years ago

Fixes #10902.

Test Plan: validate

Reviewers: goldfire, austin, hvr, jstolarek, bgamari

Reviewed By: jstolarek, bgamari

Subscribers: hvr, thomie

Differential Revision: https://phabricator.haskell.org/D1570

GHC Trac Issues: #10902

For details see #6018, Phab:D202 and the wiki page:

https://ghc.haskell.org/trac/ghc/wiki/InjectiveTypeFamilies

This patch also wires-in Maybe data type and updates haddock submodule.

Test Plan: ./validate

Reviewers: simonpj, goldfire, austin, bgamari

Subscribers: mpickering, bgamari, alanz, thomie, goldfire, simonmar,
             carter

Differential Revision: https://phabricator.haskell.org/D202

GHC Trac Issues: #6018

Signed-off-by: Austin Seipp <aseipp@pobox.com>