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| author | Simon Peyton Jones <simonpj@microsoft.com> | 2020-07-15 23:50:42 +0100 |
|---|---|---|
| committer | Marge Bot <ben+marge-bot@smart-cactus.org> | 2020-09-24 13:16:32 -0400 |
| commit | 97cff9190d346c3b51c32c88fd145fcf1e6678f1 (patch) | |
| tree | bf5f482cb2efb3ed0396cbc76cf236f50bdc8ee1 /compiler/ghc.cabal.in | |
| parent | 04d6433158d95658684cf419c4ba5725d2aa539e (diff) | |
| download | haskell-97cff9190d346c3b51c32c88fd145fcf1e6678f1.tar.gz | |
Implement Quick Look impredicativity
This patch implements Quick Look impredicativity (#18126), sticking
very closely to the design in
A quick look at impredicativity, Serrano et al, ICFP 2020
The main change is that a big chunk of GHC.Tc.Gen.Expr has been
extracted to two new modules
GHC.Tc.Gen.App
GHC.Tc.Gen.Head
which deal with typechecking n-ary applications, and the head of
such applications, respectively. Both contain a good deal of
documentation.
Three other loosely-related changes are in this patch:
* I implemented (partly by accident) points (2,3)) of the accepted GHC
proposal "Clean up printing of foralls", namely
https://github.com/ghc-proposals/ghc-proposals/blob/
master/proposals/0179-printing-foralls.rst
(see #16320).
In particular, see Note [TcRnExprMode] in GHC.Tc.Module
- :type instantiates /inferred/, but not /specified/, quantifiers
- :type +d instantiates /all/ quantifiers
- :type +v is killed off
That completes the implementation of the proposal,
since point (1) was done in
commit df08468113ab46832b7ac0a7311b608d1b418c4d
Author: Krzysztof Gogolewski <krzysztof.gogolewski@tweag.io>
Date: Mon Feb 3 21:17:11 2020 +0100
Always display inferred variables using braces
* HsRecFld (which the renamer introduces for record field selectors),
is now preserved by the typechecker, rather than being rewritten
back to HsVar. This is more uniform, and turned out to be more
convenient in the new scheme of things.
* The GHCi debugger uses a non-standard unification that allows the
unification variables to unify with polytypes. We used to hack
this by using ImpredicativeTypes, but that doesn't work anymore
so I introduces RuntimeUnkTv. See Note [RuntimeUnkTv] in
GHC.Runtime.Heap.Inspect
Updates haddock submodule.
WARNING: this patch won't validate on its own. It was too
hard to fully disentangle it from the following patch, on
type errors and kind generalisation.
Changes to tests
* Fixes #9730 (test added)
* Fixes #7026 (test added)
* Fixes most of #8808, except function `g2'` which uses a
section (which doesn't play with QL yet -- see #18126)
Test added
* Fixes #1330. NB Church1.hs subsumes Church2.hs, which is now deleted
* Fixes #17332 (test added)
* Fixes #4295
* This patch makes typecheck/should_run/T7861 fail.
But that turns out to be a pre-existing bug: #18467.
So I have just made T7861 into expect_broken(18467)
Diffstat (limited to 'compiler/ghc.cabal.in')
| -rw-r--r-- | compiler/ghc.cabal.in | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/compiler/ghc.cabal.in b/compiler/ghc.cabal.in index b58ae7f38e..9665b5e4e2 100644 --- a/compiler/ghc.cabal.in +++ b/compiler/ghc.cabal.in @@ -475,6 +475,8 @@ Library GHC.Tc.Deriv.Utils GHC.Tc.Utils.Env GHC.Tc.Gen.Expr + GHC.Tc.Gen.App + GHC.Tc.Gen.Head GHC.Tc.Gen.Foreign GHC.Tc.Deriv.Generate GHC.Tc.Deriv.Functor |