open Printf
-exception AssertFailure of string;;
exception UnificationFailure of string;;
+exception Uncertain of string;;
+exception AssertFailure of string;;
let debug_print = prerr_endline
| CicMetaSubst.MetaSubstFailure msg ->
raise (AssertFailure
((sprintf
- "Type checking error: %s in context\n%s.\nException: %s.\nBroken invariant: unification must be invoked only on well typed terms"
+ "Type checking error: %s in context\n%s\nand metasenv\n%s.\nException: %s.\nBroken invariant: unification must be invoked only on well typed terms"
(CicMetaSubst.ppterm subst term)
- (CicMetaSubst.ppcontext subst context) msg)))
+ (CicMetaSubst.ppcontext subst context)
+ (CicMetaSubst.ppmetasenv metasenv subst) msg)))
(* NUOVA UNIFICAZIONE *)
(* A substitution is a (int * Cic.term) list that associates a
let module S = CicSubstitution in
match (t1, t2) with
(C.Meta (n,ln), C.Meta (m,lm)) when n=m ->
- let ok =
+ let ok,subst,metasenv =
List.fold_left2
- (fun b t1 t2 ->
- b &&
+ (fun (b,subst,metasenv) t1 t2 ->
+ if b then true,subst,metasenv else
match t1,t2 with
None,_
- | _,None -> true
+ | _,None -> true,subst,metasenv
| Some t1', Some t2' ->
(* First possibility: restriction *)
(* Second possibility: unification *)
(* Third possibility: convertibility *)
- R.are_convertible subst context t1' t2'
- ) true ln lm
+ if R.are_convertible subst context t1' t2' then
+ true,subst,metasenv
+ else
+ (try
+ let subst,metasenv =
+ fo_unif_subst subst context metasenv t1' t2'
+ in
+ true,subst,metasenv
+ with
+ Not_found -> false,subst,metasenv)
+ ) (true,subst,metasenv) ln lm
in
if ok then
subst,metasenv
else
raise (UnificationFailure (sprintf
- "Error trying to unify %s with %s: the algorithm only tried to check convertibility of the two substitutions"
+ "Error trying to unify %s with %s: the algorithm tried to check whether the two substitutions are convertible; if they are not, it tried to unify the two substitutions. No restriction was attempted."
(CicPp.ppterm t1) (CicPp.ppterm t2)))
| (C.Meta (n,l), C.Meta (m,_)) when n>m ->
fo_unif_subst subst context metasenv t2 t1
fo_unif_subst subst context metasenv lifted_oldt t
with Not_found ->
let t',metasenv',subst' =
+ try
CicMetaSubst.delift n subst context metasenv l t
+ with
+ (CicMetaSubst.MetaSubstFailure msg)-> raise(UnificationFailure msg)
+ | (CicMetaSubst.Uncertain msg) -> raise (Uncertain msg)
in
(n, t')::subst', metasenv'
in
type_of_aux' metasenv' subst'' context t
in
fo_unif_subst subst'' context metasenv' (S.lift_meta l meta_type) tyt
- with CicTypeChecker.SortExpectedMetaFound _ ->
+ with AssertFailure _ ->
(* TODO huge hack!!!!
* we keep on unifying/refining in the hope that the problem will be
* eventually solved. In the meantime we're breaking a big invariant:
* the terms that we are unifying are no longer well typed in the
* current context (in the worst case we could even diverge)
*)
+(*
+prerr_endline "********* FROM NOW ON EVERY REASONABLE INVARIANT IS BROKEN.";
+prerr_endline "********* PROCEED AT YOUR OWN RISK. AND GOOD LUCK." ;
+*)
(subst'', metasenv'))
| (C.Var (uri1,exp_named_subst1),C.Var (uri2,exp_named_subst2))
| (C.Const (uri1,exp_named_subst1),C.Const (uri2,exp_named_subst2)) ->
else
raise (UnificationFailure (sprintf
"Can't unify %s with %s due to different constants"
- (CicPp.ppterm t1) (CicPp.ppterm t1)))
+ (CicPp.ppterm t1) (CicPp.ppterm t2)))
| C.MutInd (uri1,i1,exp_named_subst1),C.MutInd (uri2,i2,exp_named_subst2) ->
if UriManager.eq uri1 uri2 && i1 = i2 then
fo_unif_subst_exp_named_subst subst context metasenv
raise (UnificationFailure (sprintf
"Can't unify %s with %s due to different inductive constructors"
(CicPp.ppterm t1) (CicPp.ppterm t1)))
- | (C.Implicit, _) | (_, C.Implicit) -> assert false
+ | (C.Implicit _, _) | (_, C.Implicit _) -> assert false
| (C.Cast (te,ty), t2) -> fo_unif_subst subst context metasenv te t2
| (t1, C.Cast (te,ty)) -> fo_unif_subst subst context metasenv t1 te
| (C.Prod (n1,s1,t1), C.Prod (_,s2,t2)) ->