2 files changed, 20 insertions, 0 deletions
diff --git a/lib/util.ml b/lib/util.ml
index 5a5905859..4089dc03d 100644
--- a/lib/util.ml
+++ b/lib/util.ml
@@ -42,6 +42,11 @@ let located_iter2 f (_,a) (_,b) = f a b
 
 exception Error_in_file of string * (bool * string * loc) * exn
 
+(* Mapping under pairs *)
+
+let on_fst f (a,b) = (f a,b)
+let on_snd f (a,b) = (a,f b)
+
 (* Projections from triplets *)
 
 let pi1 (a,_,_) = a
@@ -552,6 +557,13 @@ let list_unique_index x =
     | [] -> raise Not_found 
   in index_x 1
 
+let list_fold_right_i f i l =
+  let rec it_list_f i l a = match l with
+    | [] -> a
+    | b::l -> f (i-1) b (it_list_f (i-1) l a)
+  in 
+  it_list_f (List.length l + i) l
+
 let list_fold_left_i f = 
   let rec it_list_f i a = function
     | [] -> a 
@@ -1169,6 +1181,7 @@ let pr_semicolon () = str ";" ++ spc ()
 let pr_bar () = str "|" ++ spc ()
 let pr_arg pr x = spc () ++ pr x
 let pr_opt pr = function None -> mt () | Some x -> pr_arg pr x
+let pr_opt_no_spc pr = function None -> mt () | Some x -> pr x
 
 let nth n = str (ordinal n)
 
diff --git a/lib/util.mli b/lib/util.mli
index e715feca3..bc1a9cc26 100644
--- a/lib/util.mli
+++ b/lib/util.mli
@@ -52,6 +52,11 @@ val located_iter2 : ('a -> 'b -> unit) -> 'a located -> 'b located -> unit
 
 exception Error_in_file of string * (bool * string * loc) * exn
 
+(* Mapping under pairs *)
+
+val on_fst : ('a -> 'b) -> 'a * 'c -> 'b * 'c
+val on_snd : ('a -> 'b) -> 'c * 'a -> 'c * 'b
+
 (*s Projections from triplets *)
 
 val pi1 : 'a * 'b * 'c -> 'a
@@ -121,6 +126,7 @@ val list_unique_index : 'a -> 'a list -> int
 val list_index0 : 'a -> 'a list -> int
 val list_iter3 : ('a -> 'b -> 'c -> unit) -> 'a list -> 'b list -> 'c list -> unit
 val list_iter_i :  (int -> 'a -> unit) -> 'a list -> unit
+val list_fold_right_i :  (int -> 'a -> 'b -> 'b) -> int -> 'a list -> 'b -> 'b
 val list_fold_left_i :  (int -> 'a -> 'b -> 'a) -> int -> 'a -> 'b list -> 'a
 val list_fold_right_and_left :
     ('a -> 'b -> 'b list -> 'a) -> 'b list -> 'a -> 'a
@@ -257,6 +263,7 @@ val pr_semicolon : unit -> std_ppcmds
 val pr_bar : unit -> std_ppcmds
 val pr_arg : ('a -> std_ppcmds) -> 'a -> std_ppcmds
 val pr_opt : ('a -> std_ppcmds) -> 'a option -> std_ppcmds
+val pr_opt_no_spc : ('a -> std_ppcmds) -> 'a option -> std_ppcmds
 val nth : int -> std_ppcmds
 
 val prlist : ('a -> std_ppcmds) -> 'a list -> std_ppcmds