Vladislav Zavialov pushed to branch wip/int-index/imp-exp-whole-namespace at Glasgow Haskell Compiler / GHC Commits: 37c94802 by Vladislav Zavialov at 2025-11-19T23:47:32+03:00 Namespace-specified wildcards in import/export lists (#25901) This change adds support for top-level namespace-specified wildcards `type ..` and `data ..` to import and export lists. Examples: import M (type ..) -- imports all type and class constructors from M import M (data ..) -- imports all data constructors and terms from M module M (type .., f) where -- exports all type and class constructors defined in M, -- plus the function 'f' The primary intended usage of this feature is in combination with module aliases, allowing namespace disambiguation: import Data.Proxy as T (type ..) -- T.Proxy is unambiguously the type constructor import Data.Proxy as D (data ..) -- D.Proxy is unambiguously the data constructor The patch accounts for the interactions of wildcards with: * Imports with `hiding` clauses * Import warnings -Wunused-imports, -Wdodgy-imports * Export warnings -Wduplicate-exports, -Wdodgy-exports Summary of the changes: 1. Move the NamespaceSpecifier type from GHC.Hs.Binds to GHC.Hs.Basic, making it possible to use it in more places in the AST. 2. Extend the AST (type: IE) with a representation of `..`, `type ..`, and `data ..` (constructor: IEWholeNamespace). Per the proposal, the plain `..` is always rejected with a dedicated error message. 3. Extend the grammar in Parser.y with productions for `..`, `type ..`, and `data ..` in both import and export lists. 4. Implement wildcard imports by updating the `filterImports` function in GHC.Rename.Names; the logic for IEWholeNamespace is roughly modeled after the Nothing (no explicit import list) case. 5. Implement wildcard exports by updating the `exports_from_avail` function in GHC.Tc.Gen.Export; the logic for IEWholeNamespace is closely modeled after the IEModuleContents case. 6. Refactor and extend diagnostics to report the new warnings and errors. See PsErrPlainWildcardImport, DodgyImportsWildcard, PsErrPlainWildcardExport, DodgyExportsWildcard, TcRnDupeWildcardExport. Note that this patch is specifically about top-level import/export items. Subordinate import/export items are left unchanged. - - - - - 79 changed files: - compiler/GHC/Hs/Basic.hs - compiler/GHC/Hs/Binds.hs - compiler/GHC/Hs/ImpExp.hs - compiler/GHC/Hs/Instances.hs - compiler/GHC/HsToCore/Docs.hs - compiler/GHC/Iface/Ext/Ast.hs - compiler/GHC/Parser.y - compiler/GHC/Parser/Errors/Ppr.hs - compiler/GHC/Parser/Errors/Types.hs - compiler/GHC/Parser/PostProcess.hs - compiler/GHC/Rename/Names.hs - compiler/GHC/Tc/Errors/Ppr.hs - compiler/GHC/Tc/Errors/Types.hs - compiler/GHC/Tc/Gen/Export.hs - compiler/GHC/Types/Error/Codes.hs - compiler/GHC/Types/Hint.hs - compiler/GHC/Types/Hint/Ppr.hs - compiler/Language/Haskell/Syntax/Extension.hs - compiler/Language/Haskell/Syntax/ImpExp.hs - docs/users_guide/9.16.1-notes.rst - docs/users_guide/exts/explicit_namespaces.rst - + testsuite/tests/module/T25901_exp_plain_wc.hs - + testsuite/tests/module/T25901_exp_plain_wc.stderr - + testsuite/tests/module/T25901_imp_plain_wc.hs - + testsuite/tests/module/T25901_imp_plain_wc.stderr - testsuite/tests/module/all.T - + testsuite/tests/rename/should_compile/T25901_exp_1.hs - + testsuite/tests/rename/should_compile/T25901_exp_1_helper.hs - + testsuite/tests/rename/should_compile/T25901_exp_2.hs - + testsuite/tests/rename/should_compile/T25901_exp_2_helper.hs - + testsuite/tests/rename/should_compile/T25901_imp_hq.hs - + testsuite/tests/rename/should_compile/T25901_imp_hu.hs - + testsuite/tests/rename/should_compile/T25901_imp_sq.hs - + testsuite/tests/rename/should_compile/T25901_imp_su.hs - testsuite/tests/rename/should_compile/all.T - + testsuite/tests/rename/should_fail/T25901_exp_fail_1.hs - + testsuite/tests/rename/should_fail/T25901_exp_fail_1.stderr - + testsuite/tests/rename/should_fail/T25901_exp_fail_1_helper.hs - + testsuite/tests/rename/should_fail/T25901_exp_fail_2.hs - + testsuite/tests/rename/should_fail/T25901_exp_fail_2.stderr - + testsuite/tests/rename/should_fail/T25901_exp_fail_2_helper.hs - + testsuite/tests/rename/should_fail/T25901_imp_hq_fail_5.hs - + testsuite/tests/rename/should_fail/T25901_imp_hq_fail_5.stderr - + testsuite/tests/rename/should_fail/T25901_imp_hq_fail_6.hs - + testsuite/tests/rename/should_fail/T25901_imp_hq_fail_6.stderr - + testsuite/tests/rename/should_fail/T25901_imp_hu_fail_4.hs - + testsuite/tests/rename/should_fail/T25901_imp_hu_fail_4.stderr - + testsuite/tests/rename/should_fail/T25901_imp_sq_fail_2.hs - + testsuite/tests/rename/should_fail/T25901_imp_sq_fail_2.stderr - + testsuite/tests/rename/should_fail/T25901_imp_sq_fail_3.hs - + testsuite/tests/rename/should_fail/T25901_imp_sq_fail_3.stderr - + testsuite/tests/rename/should_fail/T25901_imp_su_fail_1.hs - + testsuite/tests/rename/should_fail/T25901_imp_su_fail_1.stderr - testsuite/tests/rename/should_fail/all.T - + testsuite/tests/warnings/should_compile/T25901_exp_dodgy.hs - + testsuite/tests/warnings/should_compile/T25901_exp_dodgy.stderr - + testsuite/tests/warnings/should_compile/T25901_exp_dup_wc_1.hs - + testsuite/tests/warnings/should_compile/T25901_exp_dup_wc_1.stderr - + testsuite/tests/warnings/should_compile/T25901_exp_dup_wc_2.hs - + testsuite/tests/warnings/should_compile/T25901_exp_dup_wc_2.stderr - + testsuite/tests/warnings/should_compile/T25901_exp_dup_wc_3.hs - + testsuite/tests/warnings/should_compile/T25901_exp_dup_wc_3.stderr - + testsuite/tests/warnings/should_compile/T25901_exp_dup_wc_4.hs - + testsuite/tests/warnings/should_compile/T25901_exp_dup_wc_4.stderr - + testsuite/tests/warnings/should_compile/T25901_helper_1.hs - + testsuite/tests/warnings/should_compile/T25901_helper_2.hs - + testsuite/tests/warnings/should_compile/T25901_helper_3.hs - + testsuite/tests/warnings/should_compile/T25901_imp_dodgy_1.hs - + testsuite/tests/warnings/should_compile/T25901_imp_dodgy_1.stderr - + testsuite/tests/warnings/should_compile/T25901_imp_dodgy_2.hs - + testsuite/tests/warnings/should_compile/T25901_imp_dodgy_2.stderr - + testsuite/tests/warnings/should_compile/T25901_imp_unused_1.hs - + testsuite/tests/warnings/should_compile/T25901_imp_unused_1.stderr - + testsuite/tests/warnings/should_compile/T25901_imp_unused_2.hs - + testsuite/tests/warnings/should_compile/T25901_imp_unused_2.stderr - + testsuite/tests/warnings/should_compile/T25901_imp_unused_3.hs - + testsuite/tests/warnings/should_compile/T25901_imp_unused_3.stderr - testsuite/tests/warnings/should_compile/all.T - utils/check-exact/ExactPrint.hs The diff was not included because it is too large. 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