Remove the Sigma (monotonous state) API.

Reminder of (some of) the reasons for removal:

- Despite the claim in sigma.mli, it does *not* prevent evar
  leaks, something like:

  fun env evd ->
  let (evd',ev) = new_evar env evd in
  (evd,ev)

  will typecheck even with Sigma-like type annotations (with a proof of
  reflexivity)

- The API stayed embryonic. Even typing functions were not ported to
  Sigma.

- Some unsafe combinators (Unsafe.tclEVARS) were replaced with slightly
  less unsafe ones (e.g. s_enter), but those ones were not marked unsafe
  at all (despite still being so).

- There was no good story for higher order functions manipulating evar
  maps. Without higher order, one can most of the time get away with
  reusing the same name for the updated evar map.

- Most of the code doing complex things with evar maps was using unsafe
  casts to sigma. This code should be fixed, but this is an orthogonal
  issue.

Of course, this was showing a nice and elegant use of GADTs, but the
cost/benefit ratio in practice did not seem good.

1 files changed, 24 insertions, 24 deletions

diff --git a/proofs/tacmach.mli b/proofs/tacmach.mli
index 1172e55ac..3d2fa72c1 100644
--- a/proofs/tacmach.mli
+++ b/proofs/tacmach.mli
@@ -99,47 +99,47 @@ val pr_glls   : goal list sigma -> Pp.std_ppcmds
 
 (* Variants of [Tacmach] functions built with the new proof engine *)
 module New : sig
-  val pf_apply : (env -> evar_map -> 'a) -> ('b, 'r) Proofview.Goal.t -> 'a
-  val pf_global : identifier -> ('a, 'r) Proofview.Goal.t -> Globnames.global_reference
+  val pf_apply : (env -> evar_map -> 'a) -> 'b Proofview.Goal.t -> 'a
+  val pf_global : identifier -> 'a Proofview.Goal.t -> Globnames.global_reference
   (** FIXME: encapsulate the level in an existential type. *)
-  val of_old : (Proof_type.goal Evd.sigma -> 'a) -> ([ `NF ], 'r) Proofview.Goal.t -> 'a
+  val of_old : (Proof_type.goal Evd.sigma -> 'a) -> [ `NF ] Proofview.Goal.t -> 'a
 
-  val project : ('a, 'r) Proofview.Goal.t -> Evd.evar_map
-  val pf_env : ('a, 'r) Proofview.Goal.t -> Environ.env
-  val pf_concl : ('a, 'r) Proofview.Goal.t -> types
+  val project : 'a Proofview.Goal.t -> Evd.evar_map
+  val pf_env : 'a Proofview.Goal.t -> Environ.env
+  val pf_concl : 'a Proofview.Goal.t -> types
 
   (** WRONG: To be avoided at all costs, it typechecks the term entirely but
      forgets the universe constraints necessary to retypecheck it *)
-  val pf_unsafe_type_of : ('a, 'r) Proofview.Goal.t -> constr -> types
+  val pf_unsafe_type_of : 'a Proofview.Goal.t -> constr -> types
 
   (** This function does no type inference and expects an already well-typed term.
       It recomputes its type in the fastest way possible (no conversion is ever involved) *)
-  val pf_get_type_of : ('a, 'r) Proofview.Goal.t -> constr -> types
+  val pf_get_type_of : 'a Proofview.Goal.t -> constr -> types
 
   (** This function entirely type-checks the term and computes its type
       and the implied universe constraints. *)
-  val pf_type_of : ('a, 'r) Proofview.Goal.t -> constr -> evar_map * types
-  val pf_conv_x : ('a, 'r) Proofview.Goal.t -> t -> t -> bool
+  val pf_type_of : 'a Proofview.Goal.t -> constr -> evar_map * types
+  val pf_conv_x : 'a Proofview.Goal.t -> t -> t -> bool
 
-  val pf_get_new_id  : identifier -> ('a, 'r) Proofview.Goal.t -> identifier
-  val pf_ids_of_hyps : ('a, 'r) Proofview.Goal.t -> identifier list
-  val pf_hyps_types : ('a, 'r) Proofview.Goal.t -> (identifier * types) list
+  val pf_get_new_id  : identifier -> 'a Proofview.Goal.t -> identifier
+  val pf_ids_of_hyps : 'a Proofview.Goal.t -> identifier list
+  val pf_hyps_types : 'a Proofview.Goal.t -> (identifier * types) list
 
-  val pf_get_hyp : identifier -> ('a, 'r) Proofview.Goal.t -> named_declaration
-  val pf_get_hyp_typ        : identifier -> ('a, 'r) Proofview.Goal.t -> types
-  val pf_last_hyp           : ('a, 'r) Proofview.Goal.t -> named_declaration
+  val pf_get_hyp : identifier -> 'a Proofview.Goal.t -> named_declaration
+  val pf_get_hyp_typ        : identifier -> 'a Proofview.Goal.t -> types
+  val pf_last_hyp           : 'a Proofview.Goal.t -> named_declaration
 
-  val pf_nf_concl : ([ `LZ ], 'r) Proofview.Goal.t -> types
-  val pf_reduce_to_quantified_ind : ('a, 'r) Proofview.Goal.t -> types -> (inductive * EInstance.t) * types
+  val pf_nf_concl : [ `LZ ] Proofview.Goal.t -> types
+  val pf_reduce_to_quantified_ind : 'a Proofview.Goal.t -> types -> (inductive * EInstance.t) * types
 
-  val pf_hnf_constr : ('a, 'r) Proofview.Goal.t -> constr -> types
-  val pf_hnf_type_of : ('a, 'r) Proofview.Goal.t -> constr -> types
+  val pf_hnf_constr : 'a Proofview.Goal.t -> constr -> types
+  val pf_hnf_type_of : 'a Proofview.Goal.t -> constr -> types
 
-  val pf_whd_all : ('a, 'r) Proofview.Goal.t -> constr -> constr
-  val pf_compute : ('a, 'r) Proofview.Goal.t -> constr -> constr
+  val pf_whd_all : 'a Proofview.Goal.t -> constr -> constr
+  val pf_compute : 'a Proofview.Goal.t -> constr -> constr
 
-  val pf_matches : ('a, 'r) Proofview.Goal.t -> constr_pattern -> constr -> patvar_map
+  val pf_matches : 'a Proofview.Goal.t -> constr_pattern -> constr -> patvar_map
 
-  val pf_nf_evar : ('a, 'r) Proofview.Goal.t -> constr -> constr
+  val pf_nf_evar : 'a Proofview.Goal.t -> constr -> constr
 
 end