Merge PR#309: Ltac as a plugin

1 files changed, 51 insertions, 0 deletions

diff --git a/plugins/ltac/tactic_option.ml b/plugins/ltac/tactic_option.ml
new file mode 100644
index 0000000000..a5ba3b8371
--- /dev/null
+++ b/plugins/ltac/tactic_option.ml
@@ -0,0 +1,51 @@
+(************************************************************************)
+(*  v      *   The Coq Proof Assistant  /  The Coq Development Team     *)
+(* <O___,, *   INRIA - CNRS - LIX - LRI - PPS - Copyright 1999-2016     *)
+(*   \VV/  **************************************************************)
+(*    //   *      This file is distributed under the terms of the       *)
+(*         *       GNU Lesser General Public License Version 2.1        *)
+(************************************************************************)
+
+open Libobject
+open Pp
+
+let declare_tactic_option ?(default=Tacexpr.TacId []) name =
+  let locality = Summary.ref false ~name:(name^"-locality") in
+  let default_tactic_expr : Tacexpr.glob_tactic_expr ref =
+    Summary.ref default ~name:(name^"-default-tacexpr")
+  in
+  let default_tactic : Tacexpr.glob_tactic_expr ref =
+    Summary.ref !default_tactic_expr ~name:(name^"-default-tactic")
+  in
+  let set_default_tactic local t =
+    locality := local;
+    default_tactic_expr := t;
+    default_tactic := t
+  in
+  let cache (_, (local, tac)) = set_default_tactic local tac in
+  let load (_, (local, tac)) =
+    if not local then set_default_tactic local tac
+  in
+  let subst (s, (local, tac)) =
+    (local, Tacsubst.subst_tactic s tac)
+  in
+  let input : bool * Tacexpr.glob_tactic_expr -> obj =
+    declare_object
+      { (default_object name) with
+	cache_function = cache;
+	load_function = (fun _ -> load);
+	open_function = (fun _ -> load);
+	classify_function = (fun (local, tac) ->
+	  if local then Dispose else Substitute (local, tac));
+	subst_function = subst}
+  in
+  let put local tac =
+    set_default_tactic local tac;
+    Lib.add_anonymous_leaf (input (local, tac))
+  in
+  let get () = !locality, Tacinterp.eval_tactic !default_tactic in
+  let print () = 
+    Pptactic.pr_glob_tactic (Global.env ()) !default_tactic_expr ++
+      (if !locality then str" (locally defined)" else str" (globally defined)")
+  in
+  put, get, print