Dependently typed languages are well known for having a problem with code reuse. Traditional non-indexed algebraic datatypes (e.g. lists) appear alongside a plethora of indexed variations (e.g. vectors). Functions are often rewritten for both non-indexed and indexed versions of essentially the same datatype, which is a source of code duplication. We work in a Curry-style dependent type theory, where the same untyped term may be classified as both the non-indexed and indexed versions of a datatype. Many solutions have been proposed for the problem of dependently typed reuse, but we exploit Curry-style type theory in our solution to not only reuse data and programs, but do so at zero-cost (without a runtime penalty). Our work is an exercise in dependently typed generic programming, and internalizes the process of zero-cost reuse as the identity function in a Curry-style theory.

@article{paperbot277,
  title = {Generic zero-cost reuse for dependent types},
  author = {Larry Diehl and Denis Firsov and Aaron Stump},
  journal = {Proceedings of the ACM on Programming Languages},
  volume = {2},
  number = {ICFP},
  year = {2018},
  doi = {10.1145/3236799}
}