Data.Glb

Greatest lower bound

Documentation

class HasGlb a where

Types that support information intersection (glb)

Methods

glb :: a -> a -> a

Greatest lower information bound. Intersects information available from each argument.

glbs1 :: [a] -> a

n-ary glb for n > 0. Defaults to foldr1 glb. Unlike lub, we have no unit for glb.

Instances

HasGlb Bool

HasGlb Char

HasGlb Double

HasGlb Float

HasGlb Int

HasGlb Integer

HasGlb ()

HasGlb a => HasGlb [a]

HasGlb a => HasGlb (Maybe a)

HasGlb b => HasGlb (a -> b)

(HasGlb a, HasGlb b) => HasGlb (Either a b)

(HasGlb a, HasGlb b) => HasGlb (a, b)

glbBottom :: String -> a

Bottom for a glb. In the form of error "glb: bottom (<reason>)", though not really an error.

flatGlb :: Eq a => a -> a -> a

glb on flat types with equality. Gives bottom for unequal arguments.