Here comes the commit, announced long ago, of the new tactic engine.

This is a fairly large commit (around 140 files and 7000 lines of code
impacted), it will cause some troubles for sure (I've listed the know
regressions below, there is bound to be more).
At this state of developpement it brings few features to the user, as
the old tactics were
ported with no change. Changes are on the side of the developer mostly.

Here comes a list of the major changes. I will stay brief, but the code
is hopefully well documented so that it is reasonably easy to infer the
details from it.

Feature developer-side:
* Primitives for a "real" refine tactic (generating a goal for each
evar).
* Abstract type of tactics, goals and proofs
* Tactics can act on several goals (formally all the focused goals). An
interesting consequence of this is that the tactical (. ; [ . | ... ])
can be separated in two
tacticals (. ; .) and ( [ . | ... ] ) (although there is a conflict for
this particular syntax). We can also imagine a tactic to reorder the
goals.
* Possibility for a tactic to pass a value to following tactics (a
typical example is
an intro function which tells the following tactics which name it
introduced).
* backtracking primitives for tactics (it is now possible to implement a
tactical '+'
  with (a+b);c equivalent to (a;c+b;c) (itself equivalent to
(a;c||b;c)). This is a valuable
  tool to implement tactics like "auto" without nowing of the
implementation of tactics.
* A notion of proof modes, which allows to dynamically change the parser
for tactics. It is controlled at user level with the keywords Set
Default Proof Mode (this is the proof mode which is loaded at the start
of each proof) and Proof Mode (switches the proof mode of the current
proof) to control them.
* A new primitive Evd.fold_undefined which operates like an Evd.fold,
except it only goes through the evars whose body is Evar_empty. This is
a common operation throughout the code,
some of the fold-and-test-if-empty occurences have been replaced by
fold_undefined. For now,
it is only implemented as a fold-and-test, but we expect to have some
optimisations coming some day, as there can be a lot of evars in an
evar_map with this new implementation (I've observed a couple of
thousands), whereas there are rarely more than a dozen undefined ones.
Folding being a linear operation, this might result in a significant
speed-up.
* The declarative mode has been moved into the plugins. This is made
possible by the proof mode feature. I tried to document it so that it
can serve as a tutorial for a tactic mode plugin.

Features user-side:
* Unfocus does not go back to the root of the proof if several Focus-s
have been performed.
  It only goes back to the point where it was last focused.
* experimental (non-documented) support of keywords
BeginSubproof/EndSubproof:
  BeginSubproof focuses on first goal, one can unfocus only with
EndSubproof, and only
  if the proof is completed for that goal.
* experimental (non-documented) support for bullets ('+', '-' and '*')
  they act as hierarchical BeginSubproof/EndSubproof:
  First time one uses '+' (for instance) it focuses on first goal, when
the subproof is
  completed, one can use '+' again which unfocuses and focuses on next
first goal.
  Meanwhile, one cas use '*' (for instance) to focus more deeply.

Known regressions:
* The xml plugin had some functions related to proof trees. As the
structure of proof changed significantly, they do not work anymore.
* I do not know how to implement info or show script in this new engine.
Actually I don't even know what they were suppose to actually mean in
earlier versions either. I wager they would require some calm thinking
before going back to work.
* Declarative mode not entirely working (in particular proofs by
induction need to be restored).
* A bug in the inversion tactic (observed in some contributions)
* A bug in Program (observed in some contributions)
* Minor change in the 'old' type of tactics causing some contributions
to fail.
* Compilation time takes about 10-15% longer for unknown reasons (I
suspect it might be linked to the fact that I don't perform any
reduction at QED-s, and also to some linear operations on evar_map-s
(see Evd.fold_undefined above)).


git-svn-id: svn+ssh://scm.gforge.inria.fr/svn/coq/trunk@12961 85f007b7-540e-0410-9357-904b9bb8a0f7

1 files changed, 89 insertions, 0 deletions

diff --git a/proofs/proof_global.mli b/proofs/proof_global.mli
new file mode 100644
index 000000000..84a61c755
--- /dev/null
+++ b/proofs/proof_global.mli
@@ -0,0 +1,89 @@
+(************************************************************************)
+(*  v      *   The Coq Proof Assistant  /  The Coq Development Team     *)
+(* <O___,, * CNRS-Ecole Polytechnique-INRIA Futurs-Universite Paris Sud *)
+(*   \VV/  **************************************************************)
+(*    //   *      This file is distributed under the terms of the       *)
+(*         *       GNU Lesser General Public License Version 2.1        *)
+(************************************************************************)
+
+(* $Id$ *)
+
+(***********************************************************************)
+(*                                                                     *)
+(*      This module defines the global proof environment               *)
+(*      Especially it keeps tracks of whether or not there is          *)
+(*      a proof which is currently being edited.                       *)
+(*                                                                     *)
+(***********************************************************************)
+
+(* Type of proof modes :
+    - A name
+    - A function [set] to set it *from standard mode*
+    - A function [reset] to reset the *standard mode* from it *)
+type proof_mode = {
+  name : string ;
+  set : unit -> unit ;
+  reset : unit -> unit
+}
+(* Registers a new proof mode which can then be adressed by name
+    in [set_default_proof_mode].
+    One mode is already registered - the standard mode - named "No",
+    It corresponds to Coq default setting are they are set when coqtop starts. *)
+val register_proof_mode : proof_mode -> unit
+
+val there_is_a_proof : unit -> bool
+val there_are_pending_proofs : unit -> bool
+val check_no_pending_proof : unit -> unit
+
+val get_current_proof_name : unit -> Names.identifier
+val get_all_proof_names : unit -> Names.identifier list
+
+val discard : Names.identifier Util.located -> unit
+val discard_current : unit -> unit
+val discard_all : unit -> unit
+
+(* [set_proof_mode] sets the proof mode to be used after it's called. It is
+    typically called by the Proof Mode command. *)
+val set_proof_mode : string -> unit
+
+exception NoCurrentProof
+val give_me_the_proof : unit -> Proof.proof
+
+
+(* [start_proof s str goals ~init_tac ~compute_guard hook] starts 
+    a proof of name [s] and
+    conclusion [t]; [hook] is optionally a function to be applied at
+    proof end (e.g. to declare the built constructions as a coercion
+    or a setoid morphism). *)
+type lemma_possible_guards = int list list
+val start_proof : Names.identifier -> 
+                          Decl_kinds.goal_kind ->
+                          (Environ.env * Term.types) list  ->
+                          ?compute_guard:lemma_possible_guards -> 
+                          Tacexpr.declaration_hook -> 
+                          unit
+
+val close_proof : unit -> 
+                           Names.identifier * 
+                          (Entries.definition_entry list * 
+			    lemma_possible_guards * 
+			    Decl_kinds.goal_kind * 
+			    Tacexpr.declaration_hook)
+
+val suspend : unit -> unit
+val resume_last : unit -> unit
+val resume : Names.identifier -> unit
+
+(* Runs a tactic on the current proof. Raises [NoCurrentProof] is there is 
+   no current proof. *)
+val run_tactic : unit Proofview.tactic -> unit
+
+(* Sets the tactic to be used when a tactic line is closed with [...] *)
+val set_endline_tactic : unit Proofview.tactic -> unit
+
+(* Appends the endline tactic of the current proof to a tactic. *)
+val with_end_tac : unit Proofview.tactic -> unit Proofview.tactic
+
+module V82 : sig
+  val get_current_initial_conclusions : unit -> Names.identifier *(Term.types list * Decl_kinds.goal_kind * Tacexpr.declaration_hook)
+end