Last changes in type class syntax:

- curly braces mandatory for record class instances
- no mention of the unique method for definitional class instances
Turning a record or definition into a class is mostly a 
matter of changing the keywords to 'Class' and 'Instance' now.
Documentation reflects these changes, and was checked once more 
along with setoid_rewrite's and Program's.


git-svn-id: svn+ssh://scm.gforge.inria.fr/svn/coq/trunk@11797 85f007b7-540e-0410-9357-904b9bb8a0f7

1 files changed, 10 insertions, 4 deletions

diff --git a/contrib/subtac/subtac_classes.ml b/contrib/subtac/subtac_classes.ml
index cbfec12df4..15729b6266 100644
--- a/contrib/subtac/subtac_classes.ml
+++ b/contrib/subtac/subtac_classes.ml
@@ -137,11 +137,17 @@ let new_instance ?(global=false) ctx (instid, bk, cl) props ?(generalize=true) p
   let sigma = Evd.evars_of !isevars in
   let subst = List.map (Evarutil.nf_evar sigma) subst in
   let subst = 
-    let props = match props with CRecord (loc, _, fs) -> fs
-      | _ -> errorlabstrm "new_instance" (Pp.str "Expected a record declaration for the instance body") 
+    let props = 
+      match props with
+      | CRecord (loc, _, fs) -> 
+	  if List.length fs > List.length k.cl_props then 
+	    Classes.mismatched_props env' (List.map snd fs) k.cl_props;
+	  fs
+      | _ -> 
+	  if List.length k.cl_props <> 1 then 
+	    errorlabstrm "new_instance" (Pp.str "Expected a definition for the instance body")
+	  else [(dummy_loc, Nameops.out_name (pi1 (List.hd k.cl_props))), props]
     in
-      if List.length props > List.length k.cl_props then 
-	Classes.mismatched_props env' (List.map snd props) k.cl_props;
       match k.cl_props with 
       | [(na,b,ty)] -> 
 	  let term = match props with [] -> CHole (Util.dummy_loc, None) | [(_,f)] -> f | _ -> assert false in