- Second pass on implementation of let pattern. Parse "let ' par [as x]?

  [in I] := t [return pred] in b", just as SSReflect does with let:. 
  Change implementation: no longer a separate AST node, just add a case_style
  annotation on Cases to indicate it (if ML was dependently typed we
  could ensure that LetPatternStyle Cases have only one term to be
  matched and one branch, alas...). This factors out most code and we lose
  no functionality (win ! win !). Add LetPat.v test suite.

- Slight improvement of inference of return clauses for dependent
  pattern matching. If matching a variable of non-dependent type
  under a tycon that mentions it while giving no return clause, the
  dependency will be automatically infered. Examples at the end of
  DepPat. Should get rid of most explicit returns under tycons.


git-svn-id: svn+ssh://scm.gforge.inria.fr/svn/coq/trunk@10727 85f007b7-540e-0410-9357-904b9bb8a0f7

1 files changed, 2 insertions, 16 deletions

diff --git a/pretyping/pretyping.ml b/pretyping/pretyping.ml
index f9fcdb7b6..83381710d 100644
--- a/pretyping/pretyping.ml
+++ b/pretyping/pretyping.ml
@@ -582,23 +582,9 @@ module Pretyping_F (Coercion : Coercion.S) = struct
 	      mkCase (ci, pred, cj.uj_val, [|b1;b2|])
 	  in
 	    { uj_val = v; uj_type = p }
-
-    | RLetPattern (loc, c, p) ->
-	(* Just use cases typing *)
-	let j = 
-	  pretype tycon env evdref lvar 
-	    (RCases (loc, None, [c], [p]))
-	in 
-	(* Change case info *)
-	let j' = match kind_of_term j.uj_val with
-	    Case (ci, po, c, br) ->
-	      let pp_info = { ci.ci_pp_info with style = LetPatternStyle } in
-		{ j with uj_val = mkCase ({ ci with ci_pp_info = pp_info }, po, c, br) }
-	  | _ -> j
-	in j'
 	
-    | RCases (loc,po,tml,eqns) ->
-	Cases.compile_cases loc
+    | RCases (loc,sty,po,tml,eqns) ->
+	Cases.compile_cases loc sty
 	  ((fun vtyc env -> pretype vtyc env evdref lvar),evdref)
 	  tycon env (* loc *) (po,tml,eqns)