The type-settheory package

[Tags:bsd3, library]

Type classes can express sets and functions on the type level, but they are not first-class. This package expresses type-level sets and functions as types instead.

Instances are replaced by value-level proofs which can be directly manipulated; this makes quite a bit of (constructive) set theory expressible; for example, we have:

The proposition-types (derived from the :=: equality type) aren't meaningful purely by convention; they relate to the rest of Haskell as follows: A proof of A :=: B gives us a safe coercion operator A -> B (while the logic is inevitably inconsistent at compile-time since undefined proves anything, I think that we still have the property that if the Refl value is successfully pattern-matched, then the two parameters in its type are actually equal).


Versions 0.1, 0.1.1, 0.1.2, 0.1.3,
Dependencies base (==4.*), containers, mtl, syb, template-haskell, type-equality [details]
License BSD3
Author Daniel Schüssler
Stability Alpha
Category Math, Language
Source repository head: darcs get
Uploaded Wed Sep 1 02:37:05 UTC 2010 by DanielSchuessler
Distributions NixOS:
Downloads 961 total (9 in the last 30 days)
0 []
Status Docs uploaded by user
Build status unknown [no reports yet]




Maintainer's Corner

For package maintainers and hackage trustees