- (t, expty), subst, metasenv, ugraph
- with (Uncertain _ | RefineFailure _ as exn)
- when allow_coercions && !insert_coercions ->
- let whd = CicReduction.whd ~delta:false in
- let clean t s c = whd c (CicMetaSubst.apply_subst s t) in
- let infty = clean infty subst context in
- let expty = clean expty subst context in
- let t = clean t subst context in
- (*{{{*) debug_print (lazy ("COERCE_TO_SOMETHING: " ^
- CicMetaSubst.ppterm_in_context ~metasenv subst t context ^ " : " ^
- CicMetaSubst.ppterm_in_context ~metasenv subst infty context ^" ==> "^
- CicMetaSubst.ppterm_in_context ~metasenv subst expty context));(*}}}*)
- let (coerced,_),subst,metasenv,_ as result =
- match infty, expty, t with
- | Cic.Prod (nameprod,src,ty), Cic.Prod (_,src2,ty2),Cic.Fix (n,fl) ->
- (*{{{*) debug_print (lazy "FIX");
- (match fl with
- [name,i,_(* infty *),bo] ->
- let context_bo =
- Some (Cic.Name name,Cic.Decl expty)::context in
- let (rel1, _), subst, metasenv, ugraph =
- coerce_to_something_aux (Cic.Rel 1)
- (CS.lift 1 expty) (CS.lift 1 infty) subst
- metasenv context_bo ugraph in
- let bo = cs_subst rel1 (CS.lift_from 2 1 bo) in
- let (bo,_), subst, metasenv, ugraph =
- coerce_to_something_aux bo (CS.lift 1 infty) (CS.lift 1
- expty) subst
- metasenv context_bo ugraph
- in
- (Cic.Fix (n,[name,i,expty,bo]),expty),subst,metasenv,ugraph
- | _ -> assert false (* not implemented yet *)) (*}}}*)
- | _,_, Cic.MutCase (uri,tyno,outty,m,pl) ->
- (*{{{*) debug_print (lazy "CASE");
- (* {{{ helper functions *)
- let get_cl_and_left_p uri tyno outty ugraph =
- match CicEnvironment.get_obj ugraph uri with
- | Cic.InductiveDefinition (tl, _, leftno, _),ugraph ->
- let count_pis t =
- let rec aux ctx t =
- match CicReduction.whd ~delta:false ctx t with
- | Cic.Prod (name,src,tgt) ->
- let ctx = Some (name, Cic.Decl src) :: ctx in
- 1 + aux ctx tgt
- | _ -> 0
- in
- aux [] t
- in
- let rec skip_lambda_delifting t n =
- match t,n with
- | _,0 -> t
- | Cic.Lambda (_,_,t),n ->
- skip_lambda_delifting
- (CS.subst (Cic.Implicit None) t) (n - 1)
- | _ -> assert false
- in
- let get_l_r_p n = function
- | Cic.Lambda (_,Cic.MutInd _,_) -> [],[]
- | Cic.Lambda (_,Cic.Appl (Cic.MutInd _ :: args),_) ->
- HExtlib.split_nth n args
- | _ -> assert false
- in
- let _, _, ty, cl = List.nth tl tyno in
- let pis = count_pis ty in
- let rno = pis - leftno in
- let t = skip_lambda_delifting outty rno in
- let left_p, _ = get_l_r_p leftno t in
- let instantiale_with_left cl =
- List.map
- (fun ty ->
- List.fold_left
- (fun t p -> match t with
- | Cic.Prod (_,_,t) ->
- cs_subst p t
- | _-> assert false)
- ty left_p)
- cl
- in
- let cl = instantiale_with_left (List.map snd cl) in
- cl, left_p, leftno, rno, ugraph
- | _ -> raise exn
- in
- let rec keep_lambdas_and_put_expty ctx t bo right_p matched n =
- match t,n with
- | _,0 ->
- let rec mkr n = function
- | [] -> [] | _::tl -> Cic.Rel n :: mkr (n+1) tl
- in
- let bo =
- CicReplace.replace_lifting
- ~equality:(fun _ -> CicUtil.alpha_equivalence)
- ~context:ctx
- ~what:(matched::right_p)
- ~with_what:(Cic.Rel 1::List.rev (mkr 2 right_p))
- ~where:bo
- in
- bo
- | Cic.Lambda (name, src, tgt),_ ->
- Cic.Lambda (name, src,
- keep_lambdas_and_put_expty
- (Some (name, Cic.Decl src)::ctx) tgt (CS.lift 1 bo)
- (List.map (CS.lift 1) right_p) (CS.lift 1 matched) (n-1))
- | _ -> assert false
- in
- let eq_uri, eq, eq_refl =
- match LibraryObjects.eq_URI () with
- | None -> HLog.warn "no default equality"; raise exn
- | Some u -> u, Cic.MutInd(u,0,[]), Cic.MutConstruct (u,0,1,[])
- in
- let add_params
- metasenv subst context uri tyno cty outty mty m leftno i
- =
- let rec aux context outty par k mty m = function
- | Cic.Prod (name, src, tgt) ->
- let t,k =
- aux
- (Some (name, Cic.Decl src) :: context)
- (CS.lift 1 outty) (Cic.Rel k::par) (k+1)
- (CS.lift 1 mty) (CS.lift 1 m) tgt
- in
- Cic.Prod (name, src, t), k
- | Cic.MutInd _ ->
- let k =
- let k = Cic.MutConstruct (uri,tyno,i,[]) in
- if par <> [] then Cic.Appl (k::par) else k
- in
- Cic.Prod (Cic.Name "p",
- Cic.Appl [eq; mty; m; k],
- (CS.lift 1
- (CR.head_beta_reduce ~delta:false
- (Cic.Appl [outty;k])))),k
- | Cic.Appl (Cic.MutInd _::pl) ->
- let left_p,right_p = HExtlib.split_nth leftno pl in
- let has_rights = right_p <> [] in
- let k =
- let k = Cic.MutConstruct (uri,tyno,i,[]) in
- Cic.Appl (k::left_p@par)
- in
- let right_p =
- try match
- CicTypeChecker.type_of_aux' ~subst metasenv context k
- CicUniv.oblivion_ugraph
- with
- | Cic.Appl (Cic.MutInd _::args),_ ->
- snd (HExtlib.split_nth leftno args)
- | _ -> assert false
- with CicTypeChecker.TypeCheckerFailure _-> assert false
- in
- if has_rights then
- CR.head_beta_reduce ~delta:false
- (Cic.Appl (outty ::right_p @ [k])),k
- else
- Cic.Prod (Cic.Name "p",
- Cic.Appl [eq; mty; m; k],
- (CS.lift 1
- (CR.head_beta_reduce ~delta:false
- (Cic.Appl (outty ::right_p @ [k]))))),k
- | _ -> assert false
- in
- aux context outty [] 1 mty m cty
- in
- let add_lambda_for_refl_m pbo rno mty m k cty =
- (* k lives in the right context *)
- if rno <> 0 then pbo else
- let rec aux mty m = function
- | Cic.Lambda (name,src,bo), Cic.Prod (_,_,ty) ->
- Cic.Lambda (name,src,
- (aux (CS.lift 1 mty) (CS.lift 1 m) (bo,ty)))
- | t,_ ->
- Cic.Lambda (Cic.Name "p",
- Cic.Appl [eq; mty; m; k],CS.lift 1 t)
- in
- aux mty m (pbo,cty)
- in
- let add_pi_for_refl_m new_outty mty m rno =
- if rno <> 0 then new_outty else
- let rec aux m mty = function
- | Cic.Lambda (name, src, tgt) ->
- Cic.Lambda (name, src,
- aux (CS.lift 1 m) (CS.lift 1 mty) tgt)
- | t ->
- Cic.Prod
- (Cic.Anonymous, Cic.Appl [eq;mty;m;Cic.Rel 1],
- CS.lift 1 t)
- in
- aux m mty new_outty
- in (* }}} end helper functions *)
- (* constructors types with left params already instantiated *)
- let outty = CicMetaSubst.apply_subst subst outty in
- let cl, left_p, leftno,rno,ugraph =
- get_cl_and_left_p uri tyno outty ugraph
- in
- let right_p, mty =
- try
- match
- CicTypeChecker.type_of_aux' ~subst metasenv context m
- CicUniv.oblivion_ugraph
- with
- | (Cic.MutInd _ | Cic.Meta _) as mty,_ -> [], mty
- | Cic.Appl ((Cic.MutInd _|Cic.Meta _)::args) as mty,_ ->
- snd (HExtlib.split_nth leftno args), mty
- | _ -> assert false
- with CicTypeChecker.TypeCheckerFailure _ ->
- raise (AssertFailure(lazy "already ill-typed matched term"))
- in
- let new_outty =
- keep_lambdas_and_put_expty context outty expty right_p m (rno+1)
- in
- debug_print
- (lazy ("CASE: new_outty: " ^ CicMetaSubst.ppterm_in_context
- ~metasenv subst new_outty context));
- let _,pl,subst,metasenv,ugraph =
- List.fold_right2
- (fun cty pbo (i, acc, s, menv, ugraph) ->
- (* Pi k_par, (Pi H:m=(K_i left_par k_par)),
- * (new_)outty right_par (K_i left_par k_par) *)
- let infty_pbo, _ =
- add_params menv s context uri tyno
- cty outty mty m leftno i in
- debug_print
- (lazy ("CASE: infty_pbo: "^CicMetaSubst.ppterm_in_context
- ~metasenv subst infty_pbo context));
- let expty_pbo, k = (* k is (K_i left_par k_par) *)
- add_params menv s context uri tyno
- cty new_outty mty m leftno i in
- debug_print
- (lazy ("CASE: expty_pbo: "^CicMetaSubst.ppterm_in_context
- ~metasenv subst expty_pbo context));
- let pbo = add_lambda_for_refl_m pbo rno mty m k cty in
- debug_print
- (lazy ("CASE: pbo: " ^ CicMetaSubst.ppterm_in_context
- ~metasenv subst pbo context));
- let (pbo, _), subst, metasenv, ugraph =
- coerce_to_something_aux pbo infty_pbo expty_pbo
- s menv context ugraph
- in
- debug_print
- (lazy ("CASE: pbo: " ^ CicMetaSubst.ppterm_in_context
- ~metasenv subst pbo context));
- (i-1, pbo::acc, subst, metasenv, ugraph))
- cl pl (List.length pl, [], subst, metasenv, ugraph)
- in
- let new_outty = add_pi_for_refl_m new_outty mty m rno in
- debug_print
- (lazy ("CASE: new_outty: " ^ CicMetaSubst.ppterm_in_context
- ~metasenv subst new_outty context));
- let t =
- if rno = 0 then
- let refl_m=Cic.Appl[eq_refl;mty;m]in
- Cic.Appl [Cic.MutCase(uri,tyno,new_outty,m,pl);refl_m]
- else
- Cic.MutCase(uri,tyno,new_outty,m,pl)
- in
- (t, expty), subst, metasenv, ugraph (*}}}*)
- | Cic.Prod (nameprod, src, ty),Cic.Prod (_, src2, ty2), _ ->
- (*{{{*) debug_print (lazy "LAM");
- let name_con =
- FreshNamesGenerator.mk_fresh_name
- ~subst metasenv context ~typ:src2 Cic.Anonymous
- in
- let context_src2 = (Some (name_con, Cic.Decl src2) :: context) in
- (* contravariant part: the argument of f:src->ty *)
- let (rel1, _), subst, metasenv, ugraph =
- coerce_to_something_aux
- (Cic.Rel 1) (CS.lift 1 src2)
- (CS.lift 1 src) subst metasenv context_src2 ugraph
- in
- (* covariant part: the result of f(c x); x:src2; (c x):src *)
- let name_t, bo =
- match t with
- | Cic.Lambda (n,_,bo) -> n, cs_subst rel1 (CS.lift_from 2 1 bo)
- | _ -> name_con, Cic.Appl[CS.lift 1 t;rel1]
- in
- (* we fix the possible dependency problem in the source ty *)
- let ty = cs_subst rel1 (CS.lift_from 2 1 ty) in
- let (bo, _), subst, metasenv, ugraph =
- coerce_to_something_aux
- bo ty ty2 subst metasenv context_src2 ugraph