ssr: rewrite Ssripats and Ssrview in the tactic monad

Ssripats and Ssrview are now written in the Tactic Monad.
Ssripats implements the => tactical.
Ssrview implements the application of forward views.

The code is, according to my tests, 100% backward compatible.
The code is much more documented than before.
Moreover the "ist" (ltac context) used to interpret views is the correct
one (the one at ARGUMENT EXTEND interp time, not the one at TACTIC
EXTEND execution time).  Some of the code not touched by this commit
still uses the incorrect ist, so its visibility in TACTIC EXTEND
can't be removed yet.

The main changes in the code are:
- intro patterns are implemented using a state machine (a goal comes
  with a state). Ssrcommon.MakeState provides an easy way for a tactic
  to enrich the goal with with data of interest, such as the set of
  hyps to be cleared.  This cleans up the old implementation that, in
  order to thread the state, that to redefine a bunch of tclSTUFF
- the interpretation of (multiple) forward views uses the state to
  accumulate intermediate results
- the bottom of Sscommon collects a bunch of utilities written in the
  tactic monad. Most of them are the rewriting of already existing
  utilities.  When possible the old version was removed.

1 files changed, 4 insertions, 7 deletions

diff --git a/plugins/ssr/ssrelim.mli b/plugins/ssr/ssrelim.mli
index 66e202b48..b802486a0 100644
--- a/plugins/ssr/ssrelim.mli
+++ b/plugins/ssr/ssrelim.mli
@@ -13,7 +13,6 @@ open Ssrmatching_plugin
 val ssrelim :
   ?ind:(int * EConstr.types array) option ref ->
   ?is_case:bool ->
-  ?ist:Ltac_plugin.Tacinterp.interp_sign ->
   ((Ssrast.ssrhyps option * Ssrast.ssrocc) *
      Ssrmatching.cpattern)
     list ->
@@ -28,16 +27,14 @@ val ssrelim :
    as 'a) ->
   ?elim:EConstr.constr ->
   Ssrast.ssripat option ->
-  (?ist:Ltac_plugin.Tacinterp.interp_sign ->
-   'a ->
+  ( 'a ->
    Ssrast.ssripat option ->
    (Goal.goal Evd.sigma -> Goal.goal list Evd.sigma) ->
    bool -> Ssrast.ssrhyp list -> Tacmach.tactic) ->
   Goal.goal Evd.sigma -> Goal.goal list Evd.sigma
 
-val elimtac :
-  EConstr.constr ->
-  Goal.goal Evd.sigma -> Goal.goal list Evd.sigma
+val elimtac : EConstr.constr -> unit Proofview.tactic
+
 val casetac :
   EConstr.constr ->
   Goal.goal Evd.sigma -> Goal.goal list Evd.sigma
@@ -50,4 +47,4 @@ val perform_injection :
 val ssrscasetac :
   bool ->
   EConstr.constr ->
-  Goal.goal Evd.sigma -> Goal.goal list Evd.sigma
+  unit Proofview.tactic