typesys

A type expression language for R written in R.

This package includes:

• A formula-based type expression language for describing types.

• A parser to convert the type expression language into a syntax tree of S4 objects.

• A collection of S4 classes that represent general-purpose types.

• A collection of S4 classes that represent specific types in R.

• Type environments that hold (name, type) pairs, analogous to how R's environments hold (name, value) pairs.

• Additional functions for manipulating types. For example, a method to unify two types algebraically.

This package is infrastructure for RTypeInference. It might be useful if you need a formal representation for types in R or some other typed interface.

Python's typing module provided some of the inspiration for typesys. This package does not provide a way to annotate R expressions, but could be used in combination with the types package to annotate code.

Installation

typesys is unstable and under active development, so it's not yet available on CRAN. To install, open an R prompt and run:

install.packages("devtools")

devtools::install_github("nick-ulle/typesys")