add comments to API of module prove_client

src/driver/prove_client.mli

@@ -9,16 +9,30 @@
 (*                                                                  *)
 (********************************************************************)
 
-exception NotConnected
 exception AlreadyConnected
-exception InvalidAnswer of string
 
 val connect_external : string -> unit
+(** connects to an already running server, with the given socket name
+
+  raise AlreadyConnected if a server is already running
+ *)
+
 val connect_internal : unit -> unit
+(** starts a new process for a server and connects to it
+
+   raise AlreadyConnected if a server is already running
+ *)
 
-val disconnect : unit -> unit
 
 val is_connected : unit -> bool
+(** checks if a server is already running *)
+
+exception NotConnected
+(** all functions below will raise NotConnected if no server is running *)
+
+val disconnect : unit -> unit
+
+val set_max_running_provers : int -> unit
 
 val send_request :
   id:int ->
@@ -37,9 +51,9 @@ type final_answer = {
 }
 
 type answer =
-  | Started of int
+  | Started of int   (* the request with given id is running but not finished yet *)
   | Finished of final_answer
 
-val read_answers : blocking:bool -> answer list
+exception InvalidAnswer of string
 
-val set_max_running_provers : int -> unit
+val read_answers : blocking:bool -> answer list