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| author | Ryan Scott <ryan.gl.scott@gmail.com> | 2017-11-02 11:52:50 -0400 |
|---|---|---|
| committer | Ben Gamari <ben@smart-cactus.org> | 2017-11-02 11:56:26 -0400 |
| commit | 1317ba625d40fbd51cb0538b3fde28f412f30c01 (patch) | |
| tree | 6f891bba014ae2fc3e9a94c6ecdfabb021a0bbf2 /compiler/main/ErrUtils.hs | |
| parent | 29ae83374647e227d76acd896b89590fc15590d6 (diff) | |
| download | haskell-1317ba625d40fbd51cb0538b3fde28f412f30c01.tar.gz | |
Implement the EmptyDataDeriving proposal
This implements the `EmptyDataDeriving` proposal put forth in
https://github.com/ghc-proposals/ghc-proposals/blob/dbf51608/proposals/0006-deriving-empty.rst.
This has two major changes:
* The introduction of an `EmptyDataDeriving` extension, which
permits directly deriving `Eq`, `Ord`, `Read`, and `Show` instances
for empty data types.
* An overhaul in the code that is emitted in derived instances for
empty data types. To see an overview of the changes brought forth,
refer to the changes to the 8.4.1 release notes.
Test Plan: ./validate
Reviewers: bgamari, dfeuer, austin, hvr, goldfire
Reviewed By: bgamari
Subscribers: rwbarton, thomie
GHC Trac Issues: #7401, #10577, #13117
Differential Revision: https://phabricator.haskell.org/D4047
Diffstat (limited to 'compiler/main/ErrUtils.hs')
| -rw-r--r-- | compiler/main/ErrUtils.hs | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/compiler/main/ErrUtils.hs b/compiler/main/ErrUtils.hs index 5010a29513..258fc11709 100644 --- a/compiler/main/ErrUtils.hs +++ b/compiler/main/ErrUtils.hs @@ -10,7 +10,7 @@ module ErrUtils ( -- * Basic types - Validity(..), andValid, allValid, isValid, getInvalids, + Validity(..), andValid, allValid, isValid, getInvalids, orValid, Severity(..), -- * Messages @@ -110,6 +110,10 @@ allValid (v : vs) = v `andValid` allValid vs getInvalids :: [Validity] -> [MsgDoc] getInvalids vs = [d | NotValid d <- vs] +orValid :: Validity -> Validity -> Validity +orValid IsValid _ = IsValid +orValid _ v = v + -- ----------------------------------------------------------------------------- -- Basic error messages: just render a message with a source location. |