Type inference with non-structural subtyping
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We present an O(n3) time type inference algorithm for a type system with a largest typeΤ, a smallest type ⊥, and the usual ordering between function types. The algorithm infers type annotations of least shape, and it works equally well for recursive types. For the problem of typability, our algorithm is simpler than the one of Kozen, Palsberg, and Schwartzbach for type inferencewithout ⊥. This may be surprising, especially because the system with ⊥ is strictly more powerful.
KeywordsLanguages Type systems Constraints Algorithms
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