Plan 9 from Bell Labs’s /usr/web/sources/contrib/fernan/nhc98/src/prelude/Ix/Ix_Int.hs
module Ix(Ix(..)) where import CIx instance Ix Int where range (m,n) = [m .. n] index b@(m,n) i | inRange b i = i - m | True = error "Ix.Int.index: Index out of range." inRange (m,n) i = m <= i && i <= n