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| author | Adam Gundry <adam@well-typed.com> | 2020-12-23 22:22:08 +0000 |
|---|---|---|
| committer | Marge Bot <ben+marge-bot@smart-cactus.org> | 2021-02-16 04:34:43 -0500 |
| commit | 2521b041bff00458cb2c84b8747ea60d6991e329 (patch) | |
| tree | 091e47028c452050ee46fcb70aa9a01186120c1e /compiler/GHC/Rename/Module.hs | |
| parent | f422c12d26f183481ad8a833667cbfdd1c9b3e95 (diff) | |
| download | haskell-2521b041bff00458cb2c84b8747ea60d6991e329.tar.gz | |
Implement NoFieldSelectors extension (ghc-proposals 160)
Fixes #5972. This adds an extension NoFieldSelectors to disable the generation
of selector functions corresponding to record fields. When this extension is
enabled, record field selectors are not accessible as functions, but users are
still able to use them for record construction, pattern matching and updates.
See Note [NoFieldSelectors] in GHC.Rename.Env for details.
Defining the same field multiple times requires the DuplicateRecordFields
extension to be enabled, even when NoFieldSelectors is in use.
Along the way, this fixes the use of non-imported DuplicateRecordFields in GHCi
with -fimplicit-import-qualified (fixes #18729).
Moreover, it extends DisambiguateRecordFields to ignore non-fields when looking
up fields in record updates (fixes #18999), as described by
Note [DisambiguateRecordFields for updates].
Co-authored-by: Simon Hafner <hafnersimon@gmail.com>
Co-authored-by: Fumiaki Kinoshita <fumiexcel@gmail.com>
Diffstat (limited to 'compiler/GHC/Rename/Module.hs')
| -rw-r--r-- | compiler/GHC/Rename/Module.hs | 11 |
1 files changed, 6 insertions, 5 deletions
diff --git a/compiler/GHC/Rename/Module.hs b/compiler/GHC/Rename/Module.hs index 7fd73855ba..622432bf4d 100644 --- a/compiler/GHC/Rename/Module.hs +++ b/compiler/GHC/Rename/Module.hs @@ -133,7 +133,9 @@ rnSrcDecls group@(HsGroup { hs_valds = val_decls, -- Need to do this before (D2) because rnTopBindsLHS -- looks up those pattern synonyms (#9889) - extendPatSynEnv val_decls local_fix_env $ \pat_syn_bndrs -> do { + dup_fields_ok <- xopt_DuplicateRecordFields <$> getDynFlags ; + has_sel <- xopt_FieldSelectors <$> getDynFlags ; + extendPatSynEnv dup_fields_ok has_sel val_decls local_fix_env $ \pat_syn_bndrs -> do { -- (D2) Rename the left-hand sides of the value bindings. -- This depends on everything from (B) being in scope. @@ -2383,9 +2385,9 @@ rnRecConDeclFields con doc (L l fields) -- | Brings pattern synonym names and also pattern synonym selectors -- from record pattern synonyms into scope. -extendPatSynEnv :: HsValBinds GhcPs -> MiniFixityEnv +extendPatSynEnv :: DuplicateRecordFields -> FieldSelectors -> HsValBinds GhcPs -> MiniFixityEnv -> ([Name] -> TcRnIf TcGblEnv TcLclEnv a) -> TcM a -extendPatSynEnv val_decls local_fix_env thing = do { +extendPatSynEnv dup_fields_ok has_sel val_decls local_fix_env thing = do { names_with_fls <- new_ps val_decls ; let pat_syn_bndrs = concat [ name: map flSelector fields | (name, fields) <- names_with_fls ] @@ -2410,8 +2412,7 @@ extendPatSynEnv val_decls local_fix_env thing = do { = do bnd_name <- newTopSrcBinder (L bind_loc n) let field_occs = map ((\ f -> L (getLoc (rdrNameFieldOcc f)) f) . recordPatSynField) as - overload_ok <- xoptM LangExt.DuplicateRecordFields - flds <- mapM (newRecordSelector overload_ok [bnd_name]) field_occs + flds <- mapM (newRecordSelector dup_fields_ok has_sel [bnd_name]) field_occs return ((bnd_name, flds): names) | L bind_loc (PatSynBind _ (PSB { psb_id = L _ n})) <- bind = do |