----------------------------------------------------------------------
partition                                                        (Lib)
----------------------------------------------------------------------
partition : ('a -> bool) -> 'a list -> 'a list * 'a list

SYNOPSIS
Split a list by a predicate.

KEYWORDS
list

DESCRIBE
An invocation {partition P l} divides {l} into a pair of lists {(l1,l2)}.
{P} holds of each element of {l1}, and {P} does not hold of any element of
{l2}.

FAILURE
If applying {P} to any element of {l} results in failure.

EXAMPLE

- partition (fn i => i mod 2 = 0) [1,2,3,4,5,6,7,8,9];
> val it = ([2, 4, 6, 8], [1, 3, 5, 7, 9]) : int list * int list

- partition (fn _ => true) [1,2,3];
> val it = ([1, 2, 3], []) : int list * int list

- partition (fn _ => raise Fail "") ([]:int list);
> val it = ([], []) : int list * int list

- partition (fn _ => raise Fail "") [1];
! Uncaught exception:
! Fail  ""




SEEALSO
Lib.split_after, Lib.pluck.

----------------------------------------------------------------------