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| author | Ryan Scott <ryan.gl.scott@gmail.com> | 2020-09-13 08:58:40 -0400 |
|---|---|---|
| committer | Marge Bot <ben+marge-bot@smart-cactus.org> | 2020-09-15 15:21:43 -0400 |
| commit | 4283feaa9e0826211f7a71d543054c989ea32965 (patch) | |
| tree | 93f96b0599ed403b0180b0416c13f14a193bb1e4 /compiler/GHC/Parser.y | |
| parent | b3143f5a0827b640840ef241a30933dc23b69d91 (diff) | |
| download | haskell-4283feaa9e0826211f7a71d543054c989ea32965.tar.gz | |
Introduce and use DerivClauseTys (#18662)
This switches `deriv_clause_tys` so that instead of using a list of
`LHsSigType`s to represent the types in a `deriving` clause, it now
uses a sum type. `DctSingle` represents a `deriving` clause with no
enclosing parentheses, while `DctMulti` represents a clause with
enclosing parentheses. This makes pretty-printing easier and avoids
confusion between `HsParTy` and the enclosing parentheses in
`deriving` clauses, which are different semantically.
Fixes #18662.
Diffstat (limited to 'compiler/GHC/Parser.y')
| -rw-r--r-- | compiler/GHC/Parser.y | 10 |
1 files changed, 4 insertions, 6 deletions
diff --git a/compiler/GHC/Parser.y b/compiler/GHC/Parser.y index 50f63796ee..b8398dee7f 100644 --- a/compiler/GHC/Parser.y +++ b/compiler/GHC/Parser.y @@ -2276,15 +2276,13 @@ deriving :: { LHsDerivingClause GhcPs } in ams (L full_loc $ HsDerivingClause noExtField (Just $3) $2) [mj AnnDeriving $1] } -deriv_clause_types :: { Located [LHsSigType GhcPs] } +deriv_clause_types :: { LDerivClauseTys GhcPs } : qtycon { let { tc = sL1 $1 (HsTyVar noExtField NotPromoted $1) } in - sL1 $1 [mkLHsSigType tc] } - | '(' ')' {% ams (sLL $1 $> []) + sL1 $1 (DctSingle noExtField (mkLHsSigType tc)) } + | '(' ')' {% ams (sLL $1 $> (DctMulti noExtField [])) [mop $1,mcp $2] } - | '(' deriv_types ')' {% ams (sLL $1 $> $2) + | '(' deriv_types ')' {% ams (sLL $1 $> (DctMulti noExtField $2)) [mop $1,mcp $3] } - -- Glasgow extension: allow partial - -- applications in derivings ----------------------------------------------------------------------------- -- Value definitions |