Integrate a few improvements on typeclasses and Program from the equations branch

and remove equations stuff which moves to a separate plugin.

Classes:
- Ability to define classes post-hoc from constants or inductive types.
- Correctly rebuild the hint database associated to local hypotheses when 
  they are changed by a [Hint Extern] in typeclass resolution.

Tactics and proofs:
- Change [revert] so that it keeps let-ins (but not [generalize]).
- Various improvements to the [generalize_eqs] tactic to make it more robust
  and produce the smallest proof terms possible.
  Move [specialize_hypothesis] in tactics.ml as it goes hand in hand with 
  [generalize_eqs].
- A few new general purpose tactics in Program.Tactics like [revert_until]
- Make transitive closure well-foundedness proofs transparent.
- More uniform testing for metas/evars in pretyping/unification.ml
  (might introduce a few changes in the contribs).

Program:
- Better sorting of dependencies in obligations.
- Ability to start a Program definition from just a type and no obligations, 
  automatically adding an obligation for this type.
- In compilation of Program's well-founded definitions, make the functional a
  separate definition for easier reasoning.
- Add a hint database for every Program populated by [Hint Unfold]s for 
  every defined obligation constant.


git-svn-id: svn+ssh://scm.gforge.inria.fr/svn/coq/trunk@12440 85f007b7-540e-0410-9357-904b9bb8a0f7

1 files changed, 8 insertions, 0 deletions

diff --git a/lib/util.ml b/lib/util.ml
index 2815af014..794f1a6ac 100644
--- a/lib/util.ml
+++ b/lib/util.ml
@@ -1012,6 +1012,14 @@ let array_for_all_i f i v =
   let rec allrec i n = n = Array.length v || f i v.(n) && allrec (i+1) (n+1) in
   allrec i 0
 
+exception Found of int
+
+let array_find_i (pred: int -> 'a -> bool) (arr: 'a array) : int option =
+  try
+    for i=0 to Array.length arr - 1 do if pred i (arr.(i)) then raise (Found i) done;
+    None
+  with Found i -> Some i
+
 let array_hd v =
   match Array.length v with
     | 0 -> failwith "array_hd"