witness

values that witness types

https://github.com/AshleyYakeley/witness

Version on this page:	0.4
LTS Haskell 23.4:	0.6.2
Stackage Nightly 2025-01-14:	0.7
Latest on Hackage:	0.7

See all snapshots witness appears in

BSD-3-Clause licensed and maintained by Ashley Yakeley

This version can be pinned in stack with:witness-0.4@sha256:1fb17e6257589e8c3f3c5dc839d09ab312a576ca5d3d75d1ba69f8783257acac,1827

Module documentation for 0.4

Control
- Control.Category
  - Control.Category.Tensor
Data
- Data.Nat
- Data.Witness

Depends on 4 packages(full list with versions):

base, constraints, semigroupoids, transformers

A witness is a value that witnesses some sort of constraint on some list of type variables. This library provides support for simple witnesses, that constrain a type variable to a single type, and equality witnesses, that constrain two type variables to be the same type. It also provides classes for representatives, which are values that represent types. See the paper Witnesses and Open Witnesses (http://semantic.org/stuff/Open-Witnesses.pdf).