diff options
Diffstat (limited to 'lib/util.ml')
| -rw-r--r-- | lib/util.ml | 8 |
1 files changed, 8 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 |