Generics.RepLib.Bind.PermM

A slow, but hopefully correct implementation of permutations.

Documentation

data Perm a

Instances

Ord a => Eq (Perm a)

Show a => Show (Perm a)

single :: Ord a => a -> a -> Perm a

(<>) :: Ord a => Perm a -> Perm a -> Perm a

Compose two permutations. The right-hand permutation will be applied first.

apply :: Ord a => Perm a -> a -> a

support :: Ord a => Perm a -> [a]

isid :: Ord a => Perm a -> Bool

isid -- do all keys map to themselves?

join :: Ord a => Perm a -> Perm a -> Maybe (Perm a)

Join two permutation. Fail if the two permutations map the same name to two different variables.

empty :: Perm a

restrict :: Ord a => Perm a -> [a] -> Perm a