exception MetaSubstFailure of string Lazy.t
exception Uncertain of string Lazy.t
-let newmeta =
+let newmeta,maxmeta =
let maxmeta = ref 0 in
- fun () -> incr maxmeta; !maxmeta
+ (fun () -> incr maxmeta; !maxmeta),
+ (fun () -> !maxmeta)
;;
exception NotInTheList;;
in
if amount > 0 then ms, NCic.Rel (r - amount) else ms, orig
| NCic.Meta (n, (shift,lc as l)) as orig ->
- (* we ignore the subst since restrict will take care of already
- * instantiated/restricted metavariabels *)
- let (metasenv,subst as ms), restrictions_for_n, l' =
- let l = NCicUtils.expand_local_context lc in
-
- let ms, _, restrictions_for_n, l =
- List.fold_right
- (fun t (ms, i, restrictions_for_n, l) ->
- try
- let ms, t = aux (k-shift) ms t in
- ms, i-1, restrictions_for_n, t::l
- with Occur ->
- ms, i-1, i::restrictions_for_n, l)
- l (ms, List.length l, [], [])
- in
-
- ms, restrictions_for_n, pack_lc (shift, NCic.Ctx l)
+ let meta_chain =
+ try
+ Some (NCicUtils.lookup_subst n subst)
+ with
+ NCicUtils.Subst_not_found _ -> None
in
- if restrictions_for_n = [] then
- ms, if l = l' then orig else NCic.Meta (n, l')
- else
- let metasenv, subst, newmeta =
- restrict metasenv subst n restrictions_for_n
- in
- (metasenv, subst), NCic.Meta (newmeta, l')
+ (match meta_chain with
+ Some (_,_,bo,_) ->
+ aux k ms (NCicSubstitution.subst_meta l bo)
+ | None ->
+ (* we ignore the subst since restrict will take care of already
+ * instantiated/restricted metavariabels *)
+ let (metasenv,subst as ms), restrictions_for_n, l' =
+ let l = NCicUtils.expand_local_context lc in
+
+ let ms, _, restrictions_for_n, l =
+ List.fold_right
+ (fun t (ms, i, restrictions_for_n, l) ->
+ try
+ let ms, t = aux (k-shift) ms t in
+ ms, i-1, restrictions_for_n, t::l
+ with Occur ->
+ ms, i-1, i::restrictions_for_n, l)
+ l (ms, List.length l, [], [])
+ in
+
+ ms, restrictions_for_n, pack_lc (shift, NCic.Ctx l)
+ in
+ if restrictions_for_n = [] then
+ ms, if l = l' then orig else NCic.Meta (n, l')
+ else
+ let metasenv, subst, newmeta =
+ restrict metasenv subst n restrictions_for_n
+ in
+ (metasenv, subst), NCic.Meta (newmeta, l'))
| t -> NCicUntrusted.map_term_fold_a (fun _ k -> k+1) k aux ms t
in
aux 0 (metasenv,subst) t
| NCicUtils.Meta_not_found _ -> assert false
;;
-let rec flexible_arg subst = function
+let rec flexible_arg context subst = function
| NCic.Meta (i,_) | NCic.Appl (NCic.Meta (i,_) :: _)->
(try
let _,_,t,_ = List.assoc i subst in
- flexible_arg subst t
+ flexible_arg context subst t
with Not_found -> true)
+ (* this is a cheap whd, it only performs zeta-reduction.
+ *
+ * it works when the **omissis** disambiguation algorithm
+ * is run on `let x := K a b in t`, K is substituted for a
+ * ? and thus in t metavariables have a flexible Rel
+ *)
+ | NCic.Rel i ->
+ (try
+ match List.nth context (i-1)
+ with
+ | _,NCic.Def (bo,_) ->
+ flexible_arg context subst
+ (NCicSubstitution.lift i bo)
+ | _ -> false
+ with
+ | Failure _ -> assert false
+ | Invalid_argument _ -> assert false)
| _ -> false
;;
-let flexible subst l = List.exists (flexible_arg subst) l;;
-
let in_scope_tag = "tag:in_scope" ;;
let out_scope_tag_prefix = "tag:out_scope:"
let out_scope_tag n = out_scope_tag_prefix ^ string_of_int n ;;
;;
+exception Found;;
+
(* INVARIANT: we suppose that t is not another occurrence of Meta(n,_),
otherwise the occur check does not make sense in case of unification
of ?n with ?n *)
let delift ~unify metasenv subst context n l t =
+ let is_in_scope_meta subst = function
+ | NCic.Meta (i,_) ->
+ (try
+ let tag, _, _, _ = NCicUtils.lookup_subst i subst in
+ tag = Some in_scope_tag
+ with NCicUtils.Subst_not_found _ -> false)
+ | _ -> false
+ in
+ let contains_in_scope subst t =
+ let rec aux _ () = function
+ | NCic.Meta _ as t ->
+ if is_in_scope_meta subst t then raise Found
+ else ()
+ | t ->
+ if is_in_scope_meta subst t then raise Found
+ else NCicUtils.fold (fun _ () -> ()) () aux () t
+ in
+ try aux () () t; false with Found -> true
+ in
let unify_list in_scope =
match l with
| _, NCic.Irl _ -> fun _ _ _ _ _ -> None
| shift, NCic.Ctx l -> fun metasenv subst context k t ->
- if flexible_arg subst t then None else
- let lb = List.map (fun t -> t, flexible_arg subst t) l in
+ if flexible_arg context subst t || contains_in_scope subst t then None else
+ let lb = List.map (fun t -> t, flexible_arg context subst t) l in
HExtlib.list_findopt
(fun (li,flexible) i ->
if flexible || i < in_scope then None else
(NCicPp.ppterm ~context ~metasenv ~subst t))))
| NCic.Meta (i,l1) as orig ->
(try
- let tag,_,t,_ = NCicUtils.lookup_subst i subst in
- let in_scope =
+ let tag,c,t,ty = NCicUtils.lookup_subst i subst in
+ let in_scope, clear =
match tag with
- | Some tag when tag = in_scope_tag -> 0
- | Some tag when is_out_scope_tag tag -> int_of_out_scope_tag tag
- | _ -> in_scope
+ | Some tag when tag = in_scope_tag -> 0, true
+ | Some tag when is_out_scope_tag tag->int_of_out_scope_tag tag,true
+ | _ -> in_scope, false
+ in
+ let ms =
+ if not clear then ms
+ else
+ metasenv,
+ (i,(None,c,t,ty)) :: List.filter (fun j,_ -> i <> j) subst
in
aux (context,k,in_scope) ms (NCicSubstitution.subst_meta l1 t)
with NCicUtils.Subst_not_found _ ->
let lc = NCicUtils.expand_local_context lc in
let l = List.map (NCicSubstitution.lift shift) lc in
if
- List.exists
- (fun t ->
- NCicUntrusted.metas_of_term subst context t = [])
- l
+ List.exists (fun t-> NCicUntrusted.metas_of_term subst context t <> [])l
then
raise (Uncertain msg)
else
projects / helm.git / blobdiff