[obligations] Functionalize Program state

In our quest to unify all the declaration paths, an important step
is to account for the state pertaining to `Program` declarations.

Whereas regular proofs keep are kept in a stack-like structure;
obligations for constants defined by `Program` are stored in a global
map which is manipulated by almost regular open/close proof primitives.

We make this manipulation explicit by handling the program state
functionally, in a similar way than we already do for lemmas.

This requires to extend the proof DSL a bit; but IMO changes are
acceptable given the gain.

Most of the PR is routine; only remarkable change is that the hook is
called explicitly in `finish_admitted` as it had to learn about the
different types of proof_endings.

Note that we could have gone deeper and use the type system to refine
the core proof type; IMO it is still too preliminary so it is better
to do this step as an intermediate one towards a deeper unification.

1 files changed, 4 insertions, 1 deletions

diff --git a/vernac/vernacextend.ml b/vernac/vernacextend.ml
index f8a80e8feb..7317818730 100644
--- a/vernac/vernacextend.ml
+++ b/vernac/vernacextend.ml
@@ -55,11 +55,14 @@ and proof_block_name = string (** open type of delimiters *)
 type typed_vernac =
   | VtDefault of (unit -> unit)
   | VtNoProof of (unit -> unit)
-  | VtCloseProof of (lemma:Declare.Proof.t -> unit)
+  | VtCloseProof of (lemma:Declare.Proof.t -> pm:Declare.OblState.t -> Declare.OblState.t)
   | VtOpenProof of (unit -> Declare.Proof.t)
   | VtModifyProof of (pstate:Declare.Proof.t -> Declare.Proof.t)
   | VtReadProofOpt of (pstate:Declare.Proof.t option -> unit)
   | VtReadProof of (pstate:Declare.Proof.t -> unit)
+  | VtReadProgram of (pm:Declare.OblState.t -> unit)
+  | VtModifyProgram of (pm:Declare.OblState.t -> Declare.OblState.t)
+  | VtDeclareProgram of (pm:Declare.OblState.t -> Declare.Proof.t)
 
 type vernac_command = atts:Attributes.vernac_flags -> typed_vernac