On 2014-10-08 15:28, Doug McIlroy wrote:
Is there an analog or variant of type families that is indexed by values rather than by types? It depends on what you want from your indices. If all you want is to lift values to types and back, then the 'reflection' package is what you want[0]. This suffices to define modulo-bearing numbers and local typeclass instances, for example.
You might also want to look into the 'singletons' package[1], which to my understanding provides lifted functions and Template Haskell to lift values to the type level. However, I haven't investigated this package in any depth, so take this paragraph with a grain of salt. HTH, Gesh [0] - https://hackage.haskell.org/package/reflection [1] - https://hackage.haskell.org/package/singletons