Add mutually recursive types to Core concrete syntax#360
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Add mutually recursive types to Core concrete syntax#360
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added 17 commits
January 28, 2026 13:58
No polymorphism yet Add forward declarations to DDM Add name to fvar to keep track within block Change Translate to translate to mutual blocks Add rose tree test
Fix poly+destructor names+mutual rec Add some more tests Temp - fix bug in SMT poly encoding
Make datatypes handle type arguments appropriately in parser Remove scoping workaroudn with local/declared Some formatting fixes
Factor out common functionality with mutual/single datatypes Require that mutual datatypes are forward declared
atomb
previously approved these changes
Feb 3, 2026
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These changes remind me that we should have a version number for the Strata encoding in Ion. There's already a version number for the Ion version used, but not for Strata itself. But that's not for this PR.
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Description of changes:
This PR adds a mechanism for mutually recursive types to the DDM and uses that to implement mutually recursive datatypes in Strata Core's concrete syntax.
This mechanism involves two changes to the DDM:
namefield to.fvar. This arises from the fact that there is no longer a 1-1 mapping between decls and global names, since a mutual block decl defines multiple names. This name field is used to look up the specific datatype in the mutual block inCore/DDM/Translate.lean.This PR also refactors some of the datatype handling in
Core/DDM/Translate.leanto abstract common functionality for single datatypes and mutual blocks, fixes an issue where datatype names were added to the context as type variables, and includes tests demonstrating the new DDM features inStrataTest/DDM/MutualDatatypes.leanand tests implementing the full verification pipeline inStrataTest/Languages/Core/Examples/MutualDatatypes.lean.By submitting this pull request, I confirm that you can use, modify, copy, and redistribute this contribution, under the terms of your choice.