[commit: ghc] master: Overhaul -fprint-explicit-kinds to use VKA (f5d2083)

[git at git.haskell.org]

Repository : ssh://git@git.haskell.org/ghc

On branch  : master
Link       : http://ghc.haskell.org/trac/ghc/changeset/f5d2083807a03c57f194fcc3a7baf82e34aad524/ghc

>---------------------------------------------------------------

commit f5d2083807a03c57f194fcc3a7baf82e34aad524
Author: Ryan Scott <ryan.gl.scott at gmail.com>
Date:   Thu Nov 22 11:55:00 2018 -0500

    Overhaul -fprint-explicit-kinds to use VKA
    
    This patch changes the behavior of `-fprint-explicit-kinds`
    so that it displays kind argument using visible kind application.
    In other words, the flag now:
    
    1. Prints instantiations of specified variables with `@(...)`.
    2. Prints instantiations of inferred variables with `@{...}`.
    
    In addition, this patch removes the `Use -fprint-explicit-kinds to
    see the kind arguments` error message that often arises when a type
    mismatch occurs due to different kinds. Instead, whenever there is a
    kind mismatch, we now enable the `-fprint-explicit-kinds` flag
    locally to help cue to the programmer where the error lies.
    (See `Note [Kind arguments in error messages]` in `TcErrors`.)
    As a result, these funny `@{...}` things can now appear to the user
    even without turning on the `-fprint-explicit-kinds` flag explicitly,
    so I took the liberty of documenting them in the users' guide.
    
    Test Plan: ./validate
    
    Reviewers: goldfire, simonpj, bgamari
    
    Reviewed By: simonpj
    
    Subscribers: rwbarton, carter
    
    GHC Trac Issues: #15871
    
    Differential Revision: https://phabricator.haskell.org/D5314


>---------------------------------------------------------------

f5d2083807a03c57f194fcc3a7baf82e34aad524
 compiler/backpack/RnModIface.hs                    |   4 +-
 compiler/basicTypes/Var.hs                         |   2 +-
 compiler/iface/IfaceSyn.hs                         |   7 +-
 compiler/iface/IfaceType.hs                        | 224 +++++---
 compiler/iface/ToIface.hs                          |   7 +-
 compiler/typecheck/FamInst.hs                      |   9 +-
 compiler/typecheck/FunDeps.hs                      |   6 +-
 compiler/typecheck/TcErrors.hs                     |  78 ++-
 compiler/typecheck/TcType.hs                       |  95 +++-
 compiler/typecheck/TcValidity.hs                   |  48 +-
 compiler/types/TyCoRep.hs                          |  17 +-
 compiler/types/Type.hs                             |   4 +-
 docs/users_guide/using.rst                         |  20 +-
 .../tests/dependent/should_fail/T15825.stderr      |   5 +-
 .../tests/generics/T10604/T10604_deriving.stderr   | 597 ++++++++++-----------
 testsuite/tests/ghci/scripts/GhciKinds.stdout      |   2 +-
 testsuite/tests/ghci/scripts/T11376.stdout         |   8 +-
 testsuite/tests/ghci/scripts/T15341.stdout         |   4 +-
 testsuite/tests/ghci/scripts/T6018ghcifail.stderr  |  14 +-
 .../tests/indexed-types/should_fail/T9171.stderr   |   7 +-
 .../partial-sigs/should_compile/T15039b.stderr     |  10 +-
 .../partial-sigs/should_compile/T15039d.stderr     |  10 +-
 testsuite/tests/polykinds/T10570.stderr            |   3 +-
 testsuite/tests/polykinds/T14520.stderr            |   2 +-
 testsuite/tests/polykinds/T9144.stderr             |   5 +-
 testsuite/tests/polykinds/TidyClassKinds.stderr    |   2 +-
 .../tests/typecheck/should_fail/T15515.stderr      |   3 +-
 .../tests/typecheck/should_fail/T6018fail.stderr   |  17 +-
 .../typecheck/should_fail/T6018failclosed.stderr   |   7 +-
 29 files changed, 674 insertions(+), 543 deletions(-)

Diff suppressed because of size. To see it, use:

    git diff-tree --root --patch-with-stat --no-color --find-copies-harder --ignore-space-at-eol --cc f5d2083807a03c57f194fcc3a7baf82e34aad524