peano-inf-0.6.1: Number/Peano/Inf/Functions.hs

module Number.Peano.Inf.Functions 
    ( minimum
    , maximum
    , length
    ) where

import Number.Peano.Inf

import qualified Prelude as P
import Prelude hiding (minimum, maximum, length)

{- |
Minimum of the list elements.
Works also for empty lists.
-}
minimum :: [Nat] -> Nat
minimum = foldr min infinity


{- |
Maximum of the list elements.
Works also for empty lists.
-}
maximum :: [Nat] -> Nat
maximum = foldr max 0

{- | 
Lazyness properties of @Nat@ makes it ideal for lazy list length computation. 
Examples:

> length [1..] > 100

> length undefined >= 0

> length (undefined: undefined) >= 1
-}

length :: [a] -> Nat
length [] = 0
length (_:t) = succ (length t)