diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/util.ml | 8 | ||||
| -rw-r--r-- | lib/util.mli | 2 |
2 files changed, 10 insertions, 0 deletions
diff --git a/lib/util.ml b/lib/util.ml index 586365dd83..6dd0a792b2 100644 --- a/lib/util.ml +++ b/lib/util.ml @@ -207,6 +207,14 @@ let list_map3 f l1 l2 l3 = in map (l1,l2,l3) +let list_map4 f l1 l2 l3 l4 = + let rec map = function + | ([], [], [], []) -> [] + | ((h1::t1), (h2::t2), (h3::t3), (h4::t4)) -> let v = f h1 h2 h3 h4 in v::map (t1,t2,t3,t4) + | (_, _, _, _) -> invalid_arg "map4" + in + map (l1,l2,l3,l4) + let list_index x = let rec index_x n = function | y::l -> if x = y then n else index_x (succ n) l diff --git a/lib/util.mli b/lib/util.mli index 88b246a72b..d52db650ac 100644 --- a/lib/util.mli +++ b/lib/util.mli @@ -101,6 +101,8 @@ val list_map2_i : (int -> 'a -> 'b -> 'c) -> int -> 'a list -> 'b list -> 'c list val list_map3 : ('a -> 'b -> 'c -> 'd) -> 'a list -> 'b list -> 'c list -> 'd list +val list_map4 : + ('a -> 'b -> 'c -> 'd -> 'e) -> 'a list -> 'b list -> 'c list -> 'd list -> 'e list (* [list_index] returns the 1st index of an element in a list (counting from 1) *) val list_index : 'a -> 'a list -> int (* [list_unique_index x l] returns [Not_found] if [x] doesn't occur exactly once *) |