Coercions: avoid imperative data structure

1 files changed, 7 insertions, 9 deletions

diff --git a/pretyping/classops.ml b/pretyping/classops.ml
index 956e777b2..fd5081fa3 100644
--- a/pretyping/classops.ml
+++ b/pretyping/classops.ml
@@ -68,6 +68,8 @@ end
 
 module ClTypMap = Map.Make(ClTyp)
 
+module IntMap = Map.Make(Int)
+
 let cl_typ_eq t1 t2 = Int.equal (cl_typ_ord t1 t2) 0
 
 type cl_index = int
@@ -79,17 +81,13 @@ type inheritance_path = coe_index list
 (* table des classes, des coercions et graphe d'heritage *)
 
 module Bijint = struct
-  type 'a t = { v : (cl_typ * 'a) array; s : int; inv : int ClTypMap.t }
-  let empty = { v = [||]; s = 0; inv = ClTypMap.empty }
+  type 'a t = { v : (cl_typ * 'a) IntMap.t; s : int; inv : int ClTypMap.t }
+  let empty = { v = IntMap.empty; s = 0; inv = ClTypMap.empty }
   let mem y b = ClTypMap.mem y b.inv
-  let map x b = if 0 <= x && x < b.s then b.v.(x) else raise Not_found
-  let revmap y b = let n = ClTypMap.find y b.inv in (n, snd (b.v.(n)))
+  let map x b = IntMap.find x b.v
+  let revmap y b = let n = ClTypMap.find y b.inv in (n, snd (IntMap.find n b.v))
   let add x y b =
-    let v =
-      if Int.equal b.s (Array.length b.v) then
-	(let v = Array.make (b.s + 8) (x,y) in Array.blit b.v 0 v 0 b.s; v)
-      else b.v in
-    v.(b.s) <- (x,y); { v = v; s = b.s+1; inv = ClTypMap.add x b.s b.inv }
+    { v = IntMap.add b.s (x,y) b.v; s = b.s+1; inv = ClTypMap.add x b.s b.inv }
   let dom b = List.rev (ClTypMap.fold (fun x _ acc -> x::acc) b.inv [])
 end