lub-0.1.5: information operators: least upper bound (lub) and greatest lower bound (glb)

Data.Glb

Description

Greatest lower bound

Synopsis

class HasGlb a whereSource

Types that support information intersection (glb)

glb

Methods

glb :: a -> a -> aSource

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

glbs1 :: [a] -> aSource

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

foldr1 glb

lub

Instances

glbBottom :: String -> aSource

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

error "glb: bottom (<reason>)"

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

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