Moving Searchstack to CStack, and normalizing names a bit.

git-svn-id: svn+ssh://scm.gforge.inria.fr/svn/coq/trunk@16765 85f007b7-540e-0410-9357-904b9bb8a0f7

13 files changed, 137 insertions, 63 deletions

diff --git a/Makefile.common b/Makefile.common
index 1845f7164..8aaf8fceb 100644
--- a/Makefile.common
+++ b/Makefile.common
@@ -208,7 +208,7 @@ endif
 LINKCMO:=$(CORECMA) $(STATICPLUGINS)
 LINKCMX:=$(CORECMA:.cma=.cmxa) $(STATICPLUGINS:.cma=.cmxa)
 
-IDEDEPS:=lib/clib.cma lib/xml_lexer.cmo lib/xml_parser.cmo lib/xml_printer.cmo lib/searchstack.cmo
+IDEDEPS:=lib/clib.cma lib/xml_lexer.cmo lib/xml_parser.cmo lib/xml_printer.cmo
 IDECMA:=ide/ide.cma
 
 LINKIDE:=$(IDEDEPS) $(IDECMA) ide/coqide_main.ml
diff --git a/checker/check.mllib b/checker/check.mllib
index 31d2e005f..759be8729 100644
--- a/checker/check.mllib
+++ b/checker/check.mllib
@@ -21,6 +21,7 @@ CObj
 CList
 CString
 CArray
+CStack
 Util
 Future
 CUnix
diff --git a/dev/printers.mllib b/dev/printers.mllib
index 090536cc3..8e99b5247 100644
--- a/dev/printers.mllib
+++ b/dev/printers.mllib
@@ -23,6 +23,7 @@ CObj
 CList
 CString
 CArray
+CStack
 Util
 Bigint
 Dyn
diff --git a/grammar/grammar.mllib b/grammar/grammar.mllib
index b1eb01f4f..50c1cfa6a 100644
--- a/grammar/grammar.mllib
+++ b/grammar/grammar.mllib
@@ -18,6 +18,7 @@ Hashcons
 CList
 CString
 CArray
+CStack
 Util
 Bigint
 Predicate
diff --git a/ide/coqOps.ml b/ide/coqOps.ml
index 1ca949b52..cb90c0ff0 100644
--- a/ide/coqOps.ml
+++ b/ide/coqOps.ml
@@ -6,6 +6,7 @@
 (*         *       GNU Lesser General Public License Version 2.1        *)
 (************************************************************************)
 
+open Util
 open Coq
 open Ideutils
 open Interface
@@ -100,7 +101,7 @@ object(self)
   val proof = _pv
   val messages = _mv
 
-  val cmd_stack = Searchstack.create ()
+  val cmd_stack = Stack.create ()
 
   val mutable initial_state = Stateid.initial
 
@@ -232,12 +233,12 @@ object(self)
       let msg = Queue.pop feedbacks in
       let id = msg.id in
       let sentence =
-        let finder () s =
+        let finder s =
           match s.state_id, id with
-          | Some id', State id when id = id' -> `Stop s
-          | _, Edit id when id = s.edit_id -> `Stop s
-          | _ -> `Cont () in
-        try Some (Searchstack.find finder () cmd_stack)
+          | Some id', State id when id = id' -> Some s
+          | _, Edit id when id = s.edit_id -> Some s
+          | _ -> None in
+        try Some (Stack.find_map finder cmd_stack)
         with Not_found -> None in
       let log s sentence =
         Minilib.log ("Feedback " ^ s ^ " on " ^ Stateid.to_string
@@ -268,9 +269,9 @@ object(self)
             self#position_error_tag_at_sentence sentence (Some (Loc.unloc loc))
       | _ ->
           if sentence <> None then Minilib.log "Unsupported feedback message"
-          else if Searchstack.is_empty cmd_stack then ()
+          else if Stack.is_empty cmd_stack then ()
           else
-            match id, (Searchstack.top cmd_stack).state_id with
+            match id, (Stack.top cmd_stack).state_id with
             | Edit _, _ -> ()
             | State id1, Some id2 when Stateid.newer_than id2 id1 -> ()
             | _ -> Queue.add msg feedbacks (* Put back into the queue *)
@@ -341,7 +342,7 @@ object(self)
       else
         let sentence = Queue.pop queue in
         add_flag sentence `PROCESSING;
-        Searchstack.push sentence cmd_stack;
+        Stack.push sentence cmd_stack;
         if List.mem `COMMENT sentence.flags then
           let () = remove_flag sentence `PROCESSING in
           let () = self#commit_queue_transaction sentence in
@@ -361,7 +362,7 @@ object(self)
               assign_state_id sentence id;
               commit_and_continue msg
           | Fail (id, loc, msg) ->
-              let sentence = Searchstack.pop cmd_stack in
+              let sentence = Stack.pop cmd_stack in
               self#process_interp_error queue sentence loc msg id
           in
           Coq.bind query next
@@ -398,12 +399,12 @@ object(self)
     let finder (n, found, zone) ({ start; stop; state_id } as sentence) =
       let found = found || until n state_id start stop in
       match found, state_id with
-      | true, Some id -> `Stop (n, id, Some sentence, zone)
-      | _ -> `Cont (n + 1, found, sentence :: zone) in
-    try Searchstack.find finder (0, false, []) cmd_stack
+      | true, Some id -> Stop (n, id, Some sentence, zone)
+      | _ -> Next (n + 1, found, sentence :: zone) in
+    try Stack.seek finder (0, false, []) cmd_stack
     with Not_found ->
-      Searchstack.length cmd_stack, initial_state,
-      None, List.rev (Searchstack.to_list cmd_stack)
+      Stack.length cmd_stack, initial_state,
+      None, List.rev (Stack.to_list cmd_stack)
 
   (** Wrapper around the raw undo command *)
   method private backtrack_until ?(move_insert=true) until =
@@ -414,7 +415,7 @@ object(self)
       if move_insert then buffer#place_cursor ~where:self#get_start_of_input;
       self#show_goals in
     let cleanup n l =
-      for i = 1 to n do ignore(Searchstack.pop cmd_stack) done;
+      for i = 1 to n do ignore(Stack.pop cmd_stack) done;
       if l <> [] then begin
         let start = buffer#get_iter_at_mark (CList.hd l).start in
         let stop = buffer#get_iter_at_mark (CList.last l).stop in
@@ -448,12 +449,12 @@ object(self)
     messages#push Error msg;
     ignore(self#process_feedback ());
     let safe_flags s = s.flags = [ `UNSAFE ] || s.flags = [] in
-    let find_last_safe_id () s =
+    let find_last_safe_id s =
       match s.state_id with
-      | Some id when safe_flags s -> `Stop id | _ -> `Cont () in
+      | Some id -> safe_flags s | None -> false in
     try
-      let last_safe_id = Searchstack.find find_last_safe_id () cmd_stack in
-      self#backtrack_until (fun _ id _ _ -> id = Some last_safe_id)
+      let last_safe = Stack.find find_last_safe_id cmd_stack in
+      self#backtrack_until (fun _ id _ _ -> id = last_safe.state_id)
     with Not_found -> self#backtrack_until (fun _ id _ _ -> id = Some safe_id)
 
   method backtrack_last_phrase =
@@ -494,7 +495,7 @@ object(self)
           ~start:(`MARK (buffer#create_mark start))
           ~stop:(`MARK (buffer#create_mark stop))
           [] in
-      Searchstack.push sentence cmd_stack;
+      Stack.push sentence cmd_stack;
       messages#clear;
       self#show_goals
     in
@@ -528,8 +529,8 @@ object(self)
     let action () =
       if why = Coq.Unexpected then warning "Coqtop died badly. Resetting.";
       (* clear the stack *)
-      while not (Searchstack.is_empty cmd_stack) do
-        let phrase = Searchstack.pop cmd_stack in
+      while not (Stack.is_empty cmd_stack) do
+        let phrase = Stack.pop cmd_stack in
         buffer#delete_mark phrase.start;
         buffer#delete_mark phrase.stop
       done;
diff --git a/lib/searchstack.mli b/lib/cSig.mli
index 6c81a2a9c..4858d16c3 100644
--- a/lib/searchstack.mli
+++ b/lib/cSig.mli
@@ -6,20 +6,10 @@
 (*         *       GNU Lesser General Public License Version 2.1        *)
 (************************************************************************)
 
-type 'a t
-type ('a,'b) search = [ `Stop of 'b | `Cont of 'a ]
+(** Missing pervasive types from OCaml stdlib *)
 
-val create : unit -> 'a t
-val push : 'a -> 'a t -> unit
-val find : ('c -> 'a -> ('c, 'b) search) -> 'c -> 'a t -> 'b
-val is_empty : 'a t -> bool
-val iter : ('a -> unit) -> 'a t -> unit
-val clear : 'a t -> unit
-val length : 'a t -> int
+type ('a, 'b) union = Inl of 'a | Inr of 'b
+(** Union type *)
 
-(* may raise Stack.Empty *)
-val pop  : 'a t -> 'a
-val top  : 'a t -> 'a
-
-(* Extra *)
-val to_list : 'a t -> 'a list
+type ('a, 'b) seek = Stop of 'a | Next of 'b
+(** Type isomorphic to union used for browsable structures. *)
diff --git a/lib/searchstack.ml b/lib/cStack.ml
index 8d160e572..e0a3733f6 100644
--- a/lib/searchstack.ml
+++ b/lib/cStack.ml
@@ -6,18 +6,28 @@
 (*         *       GNU Lesser General Public License Version 2.1        *)
 (************************************************************************)
 
+open CSig
+
+exception Empty = Stack.Empty
+
 type 'a t = 'a list ref
-type ('a,'b) search = [ `Stop of 'b | `Cont of 'a ]
 
 let create () = ref []
 let push x l = l := x :: !l
 let pop l = match !l with [] -> raise Stack.Empty | x::xs -> l := xs; x
 let top l = match !l with [] -> raise Stack.Empty | x::_ -> x
-let find f i l =
-  let rec aux i = function
+let find f l = List.find f !l
+let find_map f l =
+  let rec aux = function
+  | [] -> raise Not_found
+  | x :: xs -> match f x with None -> aux xs | Some i -> i
+  in
+  aux !l
+let seek f accu l =
+  let rec aux accu = function
     | [] -> raise Not_found
-    | x::xs -> match f i x with `Stop x -> x | `Cont i -> aux i xs in
-  aux i !l
+    | x :: xs -> match f accu x with Stop x -> x | Next i -> aux accu xs in
+  aux accu !l
 let is_empty l = match !l with [] -> true | _ -> false
 let iter f l = List.iter f !l
 let clear l = l := []
diff --git a/lib/cStack.mli b/lib/cStack.mli
new file mode 100644
index 000000000..edca85448
--- /dev/null
+++ b/lib/cStack.mli
@@ -0,0 +1,58 @@
+(************************************************************************)
+(*  v      *   The Coq Proof Assistant  /  The Coq Development Team     *)
+(* <O___,, *   INRIA - CNRS - LIX - LRI - PPS - Copyright 1999-2010     *)
+(*   \VV/  **************************************************************)
+(*    //   *      This file is distributed under the terms of the       *)
+(*         *       GNU Lesser General Public License Version 2.1        *)
+(************************************************************************)
+
+(** Extended interface for OCaml stacks. *)
+
+open CSig
+
+type 'a t
+
+exception Empty
+(** Alias for Stack.Empty. *)
+
+val create : unit -> 'a t
+(** Create an empty stack. *)
+
+val push : 'a -> 'a t -> unit
+(** Add an element to a stack. *)
+
+val find : ('a -> bool) -> 'a t -> 'a
+(** Find the first element satisfying the predicate.
+    @raise Not_found it there is none. *)
+
+val find_map : ('a -> 'b option) -> 'a t -> 'b
+(** Find the first element that returns [Some _].
+    @raise Not_found it there is none. *)
+
+val seek : ('c -> 'a -> ('b, 'c) seek) -> 'c -> 'a t -> 'b
+(** Find the first element that returns [Some _].
+    @raise Not_found it there is none. *)
+
+val is_empty : 'a t -> bool
+(** Whether a stack is empty. *)
+
+val iter : ('a -> unit) -> 'a t -> unit
+(** Iterate a function over elements, from the last added one. *)
+
+val clear : 'a t -> unit
+(** Empty a stack. *)
+
+val length : 'a t -> int
+(** Length of a stack. *)
+
+val pop  : 'a t -> 'a
+(** Remove and returns the first element of the stack.
+    @raise Empty if empty. *)
+
+val top  : 'a t -> 'a
+(** Remove the first element of the stack without modifying it.
+    @raise Empty if empty. *)
+
+val to_list : 'a t -> 'a list
+(** Convert to a list. *)
+
diff --git a/lib/clib.mllib b/lib/clib.mllib
index 30821492e..833182bce 100644
--- a/lib/clib.mllib
+++ b/lib/clib.mllib
@@ -19,6 +19,7 @@ CObj
 CList
 CString
 CArray
+CStack
 Util
 Loc
 Flags
diff --git a/lib/lib.mllib b/lib/lib.mllib
index 9f29613d1..f45c34610 100644
--- a/lib/lib.mllib
+++ b/lib/lib.mllib
@@ -2,7 +2,6 @@ Xml_lexer
 Xml_parser
 Xml_printer
 Errors
-Searchstack
 Bigint
 Dyn
 Segmenttree
diff --git a/lib/util.ml b/lib/util.ml
index b7364cbc5..2db11131d 100644
--- a/lib/util.ml
+++ b/lib/util.ml
@@ -69,6 +69,10 @@ module Array : CArray.ExtS = CArray
 
 module Map = CMap
 
+(* Stacks *)
+
+module Stack = CStack
+
 (* Matrices *)
 
 let matrix_transpose mat =
@@ -118,7 +122,8 @@ let delayed_force f = f ()
 
 (* Misc *)
 
-type ('a,'b) union = Inl of 'a | Inr of 'b
+type ('a, 'b) union = ('a, 'b) CSig.union = Inl of 'a | Inr of 'b
+type ('a, 'b) seek = ('a, 'b) CSig.seek = Stop of 'a | Next of 'b
 
 (*s interruption *)
 
diff --git a/lib/util.mli b/lib/util.mli
index 72217fd0e..8dec93e30 100644
--- a/lib/util.mli
+++ b/lib/util.mli
@@ -63,6 +63,10 @@ module Array : CArray.ExtS
 
 module Map : module type of CMap
 
+(** {6 Stacks.} *)
+
+module Stack : module type of CStack
+
 (** {6 Streams. } *)
 
 val stream_nth : int -> 'a Stream.t -> 'a
@@ -90,7 +94,11 @@ val delayed_force : 'a delayed -> 'a
 
 (** {6 Misc. } *)
 
-type ('a, 'b) union = Inl of 'a | Inr of 'b
+type ('a, 'b) union = ('a, 'b) CSig.union = Inl of 'a | Inr of 'b
+(** Union type *)
+
+type ('a, 'b) seek = ('a, 'b) CSig.seek = Stop of 'a | Next of 'b
+(** Type isomorphic to union used for browsable structures. *)
 
 (** {6 ... } *)
 (** Coq interruption: set the following boolean reference to interrupt Coq
diff --git a/toplevel/stm.ml b/toplevel/stm.ml
index bae2a58fe..1bade01bb 100644
--- a/toplevel/stm.ml
+++ b/toplevel/stm.ml
@@ -941,7 +941,7 @@ module Backtrack : sig
 
 end = struct (* {{{ *)
 
-  module S  = Searchstack
+  module S  = Stack
 
   type hystory_elt = {
     id : Stateid.t ;
@@ -981,8 +981,7 @@ end = struct (* {{{ *)
 
   let branches_of id =
     try
-      let s = S.find (fun n s ->
-        if Stateid.equal s.id id then `Stop s else `Cont ()) () history in
+      let s = S.find (fun s -> Stateid.equal s.id id) history in
       Vcs_.branches s.vcs
     with Not_found -> assert false
  
@@ -994,19 +993,19 @@ end = struct (* {{{ *)
           (str"Reset not implemented for automatically generated constants");
         (try
           let s =
-            S.find (fun b s ->
-              if b then `Stop s else `Cont (List.mem name s.label))
+            S.seek (fun b s ->
+              if b then Stop s else Next (List.mem name s.label))
             false history in
           VtStm (VtBack s.id, true), VtNow
         with Not_found ->
           VtStm (VtBack (S.top history).id, true), VtNow)
     | VernacBack n ->
-        let s = S.find (fun n s ->
-          if Int.equal n 0 then `Stop s else `Cont (n-1)) n history in
+        let s = S.seek (fun n s ->
+          if Int.equal n 0 then Stop s else Next (n-1)) n history in
         VtStm (VtBack s.id, true), VtNow
     | VernacUndo n ->
-        let s = S.find (fun n s ->
-          if Int.equal n 0 then `Stop s else `Cont (n-1)) n history in
+        let s = S.seek (fun n s ->
+          if Int.equal n 0 then Stop s else Next (n-1)) n history in
         VtStm (VtBack s.id, true), VtLater
     | VernacUndoTo _
     | VernacRestart as e ->
@@ -1014,16 +1013,16 @@ end = struct (* {{{ *)
         let vcs = (S.top history).vcs in
         let cb, _ =
           Vcs_aux.find_proof_at_depth vcs (Vcs_aux.proof_nesting vcs) in
-        let n = S.find (fun n { vcs } ->
-          if List.mem cb (Vcs_.branches vcs) then `Cont (n+1) else `Stop n)
+        let n = S.seek (fun n { vcs } ->
+          if List.mem cb (Vcs_.branches vcs) then Next (n+1) else Stop n)
           0 history in
-        let s = S.find (fun n s ->
-          if Int.equal n 0 then `Stop s else `Cont (n-1)) (n-m-1) history in
+        let s = S.seek (fun n s ->
+          if Int.equal n 0 then Stop s else Next (n-1)) (n-m-1) history in
         VtStm (VtBack s.id, true), VtLater
     | VernacAbortAll ->
-        let s = S.find (fun () s ->
-          match Vcs_.branches s.vcs with [_] -> `Stop s | _ -> `Cont ())
-          () history in
+        let s = S.find (fun s ->
+          match Vcs_.branches s.vcs with [_] -> true | _ -> false)
+          history in
         VtStm (VtBack s.id, true), VtLater
     | VernacBacktrack (id,_,_)
     | VernacBackTo id ->