Show HN: Foxp – a TypeScript type checker enabling pseudo dependent types

2 points

a year ago

Hello. I’ve created a TypeScript package that enables dependent-type–like checks by implementing a scripting language called CionLisp entirely at the type level. By extracting types from runtime values, it enables type validations not natively supported by TypeScript.

Using this, I’ve implemented several features, including:

- Division-by-zero detection

- Length-indexed vectors (similar to Vect n in idris)

- Safe accessors (similar to Lenses)

Additionally, anything that can be expressed on CionLisp and resolved at type level—such as email validation via regex—can potentially be type-checked as well.

Please note that this is still in an alpha stage, so use with caution.

Thank you for your interest.