Any plans for mypy equivalent for R?

Python's typing package is a boon for module development. When developing R packages I often wish for some form of static type checking ala mypy. Does anyone know of any plans to introduce something similar for R? I have caught numerous coding errors and am able to clearly document function contracts using the gradual typing enabled by mypy.

Something similar for R would be hugely beneficial for package development and documentation. I realize this would be a monumental undertaking and am just curious if it has been discussed by folks in r-devel or Rstudio (or elsewhere) as a desired feature.

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There are some packages that implement strong typing in R:

And you might also be interested in these related packages:

  • zatonovo/lambda.r - Provides a syntax for functional programming, including a type system (CRAN)
  • r-lib/vctrs - This package doesn't introduce a type system, but it tries to make the existing types more stable (e.g. make the outcome more predictable when combining vectors with c()) (CRAN)
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Thanks for the links. Looks like these implement runtime checks to enforce the typing. It likely doesn't exist, but I am really wishing for a static type checker that can be run with a linting step ala mypy. I'm not sure R's syntax can support that, though. Maybe with something like python's typing for python 2 that relied on comments.

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I have thought about it, and have a simple package on CRAN {types} showing how you can add types with ? https://cran.r-project.org/web/packages/types/README.html.

But the bulk of the work would be using these types of annotations to do static analysis, or doing other things like adding optional type checks to the code. https://github.com/jimhester/typeCheck was an exploration along these lines.

Aviral Goel is also doing ongoing research at Northeastern on type annotations for R, e.g. with his https://github.com/aviralg/annotatr project.

But the bottom line is none of these projects is anywhere close to mypy and it would take a considerable investment before they provide much of a productivity boost.

There have been no serious talks at RStudio I am aware of to provide a mypy equivalent, but if more community members express interest in gradual typing maybe that would change.

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