Merge PR #6844: Adding tclBINDFIRST/tclBINDLAST, generalizing type of tclTHENFIRST/tclTHENLAST, informative version of shelve unifiable

4 files changed, 48 insertions, 2 deletions

diff --git a/engine/proofview.ml b/engine/proofview.ml
index 22271dd02..639f48e77 100644
--- a/engine/proofview.ml
+++ b/engine/proofview.ml
@@ -710,13 +710,19 @@ let partition_unifiable sigma l =
 (** Shelves the unifiable goals under focus, i.e. the goals which
     appear in other goals under focus (the unfocused goals are not
     considered). *)
-let shelve_unifiable =
+let shelve_unifiable_informative =
   let open Proof in
   Pv.get >>= fun initial ->
   let (u,n) = partition_unifiable initial.solution initial.comb in
   Comb.set n >>
   InfoL.leaf (Info.Tactic (fun () -> Pp.str"shelve_unifiable")) >>
-  Shelf.modify (fun gls -> gls @ CList.map drop_state u)
+  let u = CList.map drop_state u in
+  Shelf.modify (fun gls -> gls @ u) >>
+  tclUNIT u
+
+let shelve_unifiable =
+  let open Proof in
+  shelve_unifiable_informative >>= fun _ -> tclUNIT ()
 
 (** [guard_no_unifiable] returns the list of unifiable goals if some
     goals are unifiable (see {!shelve_unifiable}) in the current focus. *)
@@ -1035,6 +1041,8 @@ module Unsafe = struct
 
   let advance = Evarutil.advance
 
+  let undefined = undefined
+
   let mark_as_unresolvable p gl =
     { p with solution = mark_in_evm ~goal:false p.solution gl }
 
diff --git a/engine/proofview.mli b/engine/proofview.mli
index e7be66552..1905686fe 100644
--- a/engine/proofview.mli
+++ b/engine/proofview.mli
@@ -326,6 +326,9 @@ val unifiable : Evd.evar_map -> Evar.t -> Evar.t list -> bool
     considered). *)
 val shelve_unifiable : unit tactic
 
+(** Idem but also returns the list of shelved variables *)
+val shelve_unifiable_informative : Evar.t list tactic
+
 (** [guard_no_unifiable] returns the list of unifiable goals if some
     goals are unifiable (see {!shelve_unifiable}) in the current focus. *)
 val guard_no_unifiable : Names.Name.t list option tactic
@@ -466,6 +469,12 @@ module Unsafe : sig
       solved. *)
   val advance : Evd.evar_map -> Evar.t -> Evar.t option
 
+  (** [undefined sigma l] applies [advance] to the goals of [l], then
+      returns the subset of resulting goals which have not yet been
+      defined *)
+  val undefined : Evd.evar_map -> Proofview_monad.goal_with_state list ->
+    Proofview_monad.goal_with_state list
+
   val typeclass_resolvable : unit Evd.Store.field
 
 end
diff --git a/tactics/tacticals.ml b/tactics/tacticals.ml
index 958a205a1..a97ae8f65 100644
--- a/tactics/tacticals.ml
+++ b/tactics/tacticals.ml
@@ -369,9 +369,36 @@ module New = struct
     tclTHENSFIRSTn t1 l (tclUNIT())
   let tclTHENFIRST t1 t2 =
     tclTHENFIRSTn t1 [|t2|]
+
+  let tclBINDFIRST t1 t2 =
+    t1 >>= fun ans ->
+    Proofview.Unsafe.tclGETGOALS >>= fun gls ->
+    match gls with
+    | [] -> tclFAIL 0 (str "Expect at least one goal.")
+    | hd::tl ->
+    Proofview.Unsafe.tclSETGOALS [hd] <*> t2 ans >>= fun ans ->
+    Proofview.Unsafe.tclNEWGOALS tl <*>
+    Proofview.tclUNIT ans
+
   let tclTHENLASTn t1 l =
     tclTHENS3PARTS t1 [||] (tclUNIT()) l
   let tclTHENLAST t1 t2 = tclTHENLASTn t1 [|t2|]
+
+  let option_of_failure f x = try Some (f x) with Failure _ -> None
+
+  let tclBINDLAST t1 t2 =
+    t1 >>= fun ans ->
+    Proofview.Unsafe.tclGETGOALS >>= fun gls ->
+    match option_of_failure List.sep_last gls with
+    | None -> tclFAIL 0 (str "Expect at least one goal.")
+    | Some (last,firstn) ->
+    Proofview.Unsafe.tclSETGOALS [last] <*> t2 ans >>= fun ans ->
+    Proofview.Unsafe.tclGETGOALS >>= fun newgls ->
+    tclEVARMAP >>= fun sigma ->
+    let firstn = Proofview.Unsafe.undefined sigma firstn in
+    Proofview.Unsafe.tclSETGOALS (firstn@newgls) <*>
+    Proofview.tclUNIT ans
+
   let tclTHENS t l =
     tclINDEPENDENT begin
       t <*>Proofview.tclORELSE (* converts the [SizeMismatch] error into an ltac error *)
diff --git a/tactics/tacticals.mli b/tactics/tacticals.mli
index f0ebac780..340d8fbf3 100644
--- a/tactics/tacticals.mli
+++ b/tactics/tacticals.mli
@@ -196,8 +196,10 @@ module New : sig
   (** [tclTHENFIRST tac1 tac2 gls] applies the tactic [tac1] to [gls]
       and [tac2] to the first resulting subgoal *)
   val tclTHENFIRST : unit tactic -> unit tactic -> unit tactic
+  val tclBINDFIRST : 'a tactic -> ('a -> 'b tactic) -> 'b tactic
   val tclTHENLASTn : unit tactic -> unit tactic array -> unit tactic
   val tclTHENLAST  : unit tactic -> unit tactic -> unit tactic
+  val tclBINDLAST  : 'a tactic -> ('a -> 'b tactic) -> 'b tactic
   (* [tclTHENS t l = t <*> tclDISPATCH l] *)
   val tclTHENS : unit tactic -> unit tactic list -> unit tactic
   (* [tclTHENLIST [t1;…;tn]] is [t1<*>…<*>tn] *)