Data.Vinyl.Constraint

Documentation

class xs <: ys where

One record is a subtype of another if the fields of the latter are a subset of the fields of the former.

Methods

cast :: Rec el f xs -> Rec el f ys

Instances

(<:) k xs ([] k)

((∈) k y xs, (<:) k xs ys) => (<:) k xs ((:) k y ys)

type (:~:) r1 r2 = (r1 <: r2, r2 <: r1)

If two records types are subtypes of each other, that means that they differ only in order of fields.

(~=) :: (Eq (Rec el f xs), xs :~: ys) => Rec el f xs -> Rec el f ys -> Bool

Term-level record congruence.

type family RecAll el f rs c :: Constraint

Instances

type RecAll k k1 el f ([] k) c = ()

type RecAll k * el f ((:) k r rs) c = (c (f (($) * k el r)), RecAll k * el f rs c)