stdlib/map: Add some usage exemple in the documentation.

(Patch by Nicolas Braud-Santoni)

git-svn-id: http://caml.inria.fr/svn/ocaml/trunk@14730 f963ae5c-01c2-4b8c-9fe0-0dff7051ff02

2 files changed, 41 insertions, 0 deletions

diff --git a/stdlib/map.mli b/stdlib/map.mli
index 6dd371b52..abf453161 100644
--- a/stdlib/map.mli
+++ b/stdlib/map.mli
@@ -19,6 +19,26 @@
    All operations over maps are purely applicative (no side-effects).
    The implementation uses balanced binary trees, and therefore searching
    and insertion take time logarithmic in the size of the map.
+
+   For instance:
+   {[
+     module IntPairs =
+       struct
+         type t = int * int
+         let compare (x0,y0) (x1,y1) =
+           match Pervasives.compare x0 x1 with
+               0 -> Pervasives.compare y0 y1
+             | c -> c
+       end
+
+     module PairsMap = Map.Make(IntPairs)
+
+     let m = PairsMap.(empty |> add (0,1) "hello" |> add (1,0) "world")
+   ]}
+
+   This creates a new module [PairsMap], with a new type ['a PairsMap.t]
+   of maps from [int * int] to ['a]. In this example, [m] contains [string]
+   values so its type is [string PairsMap.t].
 *)
 
 module type OrderedType =
diff --git a/stdlib/set.mli b/stdlib/set.mli
index 556ee9388..1b67398ee 100644
--- a/stdlib/set.mli
+++ b/stdlib/set.mli
@@ -19,6 +19,27 @@
    The implementation uses balanced binary trees, and is therefore
    reasonably efficient: insertion and membership take time
    logarithmic in the size of the set, for instance.
+
+   The [Make] functor constructs implementations for any type, given a
+   [compare] function.
+   For instance:
+   {[
+     module IntPairs =
+       struct
+         type t = int * int
+         let compare (x0,y0) (x1,y1) =
+           match Pervasives.compare x0 x1 with
+               0 -> Pervasives.compare y0 y1
+             | c -> c
+       end
+
+     module PairsSet = Set.Make(IntPairs)
+
+     let m = PairsSet.(empty |> add (2,3) |> add (5,7) |> add (11,13))
+   ]}
+
+   This creates a new module [PairsSet], with a new type [PairsSet.t]
+   of sets of [int * int].
 *)
 
 module type OrderedType =