Deep and shallow types for gradual languages
Ben Greenman · 2022
Sound gradual types come in many forms and offer varying levels of soundness. Two extremes are deep types and shallow types. Deep types offer compositional guarantees but depend on expensive higher-order contracts. Shallow types enforce only local properties, but can be implemented with first-order checks. This paper presents a language design that supports both deep and shallow types to utilize their complementary strengths.