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| author | CarrieMY <carrie.xmy@gmail.com> | 2022-05-25 16:43:03 +0200 |
|---|---|---|
| committer | sheaf <sam.derbyshire@gmail.com> | 2022-05-25 16:43:03 +0200 |
| commit | e74fc066cb33e5b7ae0d37cedb30230c597ef1ce (patch) | |
| tree | cc17cbbe235ada53bdac93e06cbfe4ca632ffa4a /compiler/GHC/Tc/Errors | |
| parent | 2ff18e390b119c611b3dd429b76cfcbf36ef9545 (diff) | |
| download | haskell-wip/T18802.tar.gz | |
Desugar RecordUpd in `tcExpr`wip/T18802
This patch typechecks record updates by desugaring them inside
the typechecker using the HsExpansion mechanism, and then typechecking
this desugared result.
Example:
data T p q = T1 { x :: Int, y :: Bool, z :: Char }
| T2 { v :: Char }
| T3 { x :: Int }
| T4 { p :: Float, y :: Bool, x :: Int }
| T5
The record update `e { x=e1, y=e2 }` desugars as follows
e { x=e1, y=e2 }
===>
let { x' = e1; y' = e2 } in
case e of
T1 _ _ z -> T1 x' y' z
T4 p _ _ -> T4 p y' x'
The desugared expression is put into an HsExpansion, and we typecheck
that.
The full details are given in Note [Record Updates] in GHC.Tc.Gen.Expr.
Fixes #2595 #3632 #10808 #10856 #16501 #18311 #18802 #21158 #21289
Updates haddock submodule
Diffstat (limited to 'compiler/GHC/Tc/Errors')
| -rw-r--r-- | compiler/GHC/Tc/Errors/Types.hs | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/compiler/GHC/Tc/Errors/Types.hs b/compiler/GHC/Tc/Errors/Types.hs index 182818616a..e1679d82d0 100644 --- a/compiler/GHC/Tc/Errors/Types.hs +++ b/compiler/GHC/Tc/Errors/Types.hs @@ -82,7 +82,7 @@ import GHC.Types.Error import GHC.Types.Hint (UntickedPromotedThing(..)) import GHC.Types.FieldLabel (FieldLabelString) import GHC.Types.ForeignCall (CLabelString) -import GHC.Types.Name (Name, OccName, getSrcLoc) +import GHC.Types.Name (Name, OccName, getSrcLoc, getSrcSpan) import GHC.Types.Name.Reader import GHC.Types.SrcLoc import GHC.Types.TyThing (TyThing) @@ -2950,14 +2950,15 @@ pprRelevantBindings :: RelevantBindings -> SDoc -- This function should be in "GHC.Tc.Errors.Ppr", -- but's it's here for the moment as it's needed in "GHC.Tc.Errors". pprRelevantBindings (RelevantBindings bds ran_out_of_fuel) = - ppUnless (null bds) $ + ppUnless (null rel_bds) $ hang (text "Relevant bindings include") - 2 (vcat (map ppr_binding bds) $$ ppWhen ran_out_of_fuel discardMsg) + 2 (vcat (map ppr_binding rel_bds) $$ ppWhen ran_out_of_fuel discardMsg) where ppr_binding (nm, tidy_ty) = sep [ pprPrefixOcc nm <+> dcolon <+> ppr tidy_ty , nest 2 (parens (text "bound at" <+> ppr (getSrcLoc nm)))] + rel_bds = filter (not . isGeneratedSrcSpan . getSrcSpan . fst) bds discardMsg :: SDoc discardMsg = text "(Some bindings suppressed;" <+> |