Complete and Decidable Type Inference for GADTs

GADTs have proven to be an invaluable language extension, a.o. for ensuring data invariants and program correctness. Unfortunately, they pose a tough problem for type inference: we lose the principal-type property, which is necessary for modular type inference.

We present a novel and simplified type inference approach for local type assumptions from GADT pattern matches. Our approach is complete and decidable, while more liberal than previous such approaches.

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In  Proceedings of the 14th ACM SIGPLAN International Conference on Functional Programming

Publisher  Association for Computing Machinery, Inc.
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