module Incubator:sig
..end
val eq_by : ('a -> 'b) -> 'a BatOrd.eq
val comp_by : ('a -> 'b) -> 'a BatOrd.comp
val ord_by : ('a -> 'b) -> 'a BatOrd.ord
Build a eq
, cmp
or ord
function from a projection function.
For example, if you wanted to compare integers based on their
lowest 4 bits, you could write let cmp_bot4 = cmp_by (fun x
and use cmp_bot4 as the desired integer
comparator.
-> x land 0xf)