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Diffstat (limited to 'pretyping/term_dnet.ml')
-rw-r--r-- | pretyping/term_dnet.ml | 404 |
1 files changed, 404 insertions, 0 deletions
diff --git a/pretyping/term_dnet.ml b/pretyping/term_dnet.ml new file mode 100644 index 00000000..04e328cb --- /dev/null +++ b/pretyping/term_dnet.ml @@ -0,0 +1,404 @@ +(************************************************************************) +(* v * The Coq Proof Assistant / The Coq Development Team *) +(* <O___,, * CNRS-Ecole Polytechnique-INRIA Futurs-Universite Paris Sud *) +(* \VV/ **************************************************************) +(* // * This file is distributed under the terms of the *) +(* * GNU Lesser General Public License Version 2.1 *) +(************************************************************************) + +(* $Id:$ *) + +(*i*) +open Util +open Term +open Sign +open Names +open Libnames +open Mod_subst +open Pp (* debug *) +(*i*) + + +(* Representation/approximation of terms to use in the dnet: + * + * - no meta or evar (use ['a pattern] for that) + * + * - [Rel]s and [Sort]s are not taken into account (that's why we need + * a second pass of linear filterin on the results - it's not a perfect + * term indexing structure) + + * - Foralls and LetIns are represented by a context DCtx (a list of + * generalization, similar to rel_context, and coded with DCons and + * DNil). This allows for matching under an unfinished context + *) + +module DTerm = +struct + + type 't t = + | DRel + | DSort + | DRef of global_reference + | DCtx of 't * 't (* (binding list, subterm) = Prods and LetIns *) + | DLambda of 't * 't + | DApp of 't * 't (* binary app *) + | DCase of case_info * 't * 't * 't array + | DFix of int array * int * 't array * 't array + | DCoFix of int * 't array * 't array + + (* special constructors only inside the left-hand side of DCtx or + DApp. Used to encode lists of foralls/letins/apps as contexts *) + | DCons of ('t * 't option) * 't + | DNil + + type dconstr = dconstr t + + (* debug *) + let rec pr_dconstr f : 'a t -> std_ppcmds = function + | DRel -> str "*" + | DSort -> str "Sort" + | DRef _ -> str "Ref" + | DCtx (ctx,t) -> f ctx ++ spc() ++ str "|-" ++ spc () ++ f t + | DLambda (t1,t2) -> str "fun"++ spc() ++ f t1 ++ spc() ++ str"->" ++ spc() ++ f t2 + | DApp (t1,t2) -> f t1 ++ spc() ++ f t2 + | DCase (_,t1,t2,ta) -> str "case" + | DFix _ -> str "fix" + | DCoFix _ -> str "cofix" + | DCons ((t,dopt),tl) -> f t ++ (match dopt with + Some t' -> str ":=" ++ f t' + | None -> str "") ++ spc() ++ str "::" ++ spc() ++ f tl + | DNil -> str "[]" + + (* + * Functional iterators for the t datatype + * a.k.a boring and error-prone boilerplate code + *) + + let map f = function + | (DRel | DSort | DNil | DRef _) as c -> c + | DCtx (ctx,c) -> DCtx (f ctx, f c) + | DLambda (t,c) -> DLambda (f t, f c) + | DApp (t,u) -> DApp (f t,f u) + | DCase (ci,p,c,bl) -> DCase (ci, f p, f c, Array.map f bl) + | DFix (ia,i,ta,ca) -> + DFix (ia,i,Array.map f ta,Array.map f ca) + | DCoFix(i,ta,ca) -> + DCoFix (i,Array.map f ta,Array.map f ca) + | DCons ((t,topt),u) -> DCons ((f t,Option.map f topt), f u) + + let compare x y = + let make_name n = + match n with + | DRef(ConstRef con) -> + DRef(ConstRef(constant_of_kn(canonical_con con))) + | DRef(IndRef (kn,i)) -> + DRef(IndRef(mind_of_kn(canonical_mind kn),i)) + | DRef(ConstructRef ((kn,i),j ))-> + DRef(ConstructRef((mind_of_kn(canonical_mind kn),i),j)) + | k -> k in + Pervasives.compare (make_name x) (make_name y) + + let fold f acc = function + | (DRel | DNil | DSort | DRef _) -> acc + | DCtx (ctx,c) -> f (f acc ctx) c + | DLambda (t,c) -> f (f acc t) c + | DApp (t,u) -> f (f acc t) u + | DCase (ci,p,c,bl) -> Array.fold_left f (f (f acc p) c) bl + | DFix (ia,i,ta,ca) -> + Array.fold_left f (Array.fold_left f acc ta) ca + | DCoFix(i,ta,ca) -> + Array.fold_left f (Array.fold_left f acc ta) ca + | DCons ((t,topt),u) -> f (Option.fold_left f (f acc t) topt) u + + let choose f = function + | (DRel | DSort | DNil | DRef _) -> invalid_arg "choose" + | DCtx (ctx,c) -> f ctx + | DLambda (t,c) -> f t + | DApp (t,u) -> f u + | DCase (ci,p,c,bl) -> f c + | DFix (ia,i,ta,ca) -> f ta.(0) + | DCoFix (i,ta,ca) -> f ta.(0) + | DCons ((t,topt),u) -> f u + + let fold2 (f:'a -> 'b -> 'c -> 'a) (acc:'a) (c1:'b t) (c2:'c t) : 'a = + let head w = map (fun _ -> ()) w in + if compare (head c1) (head c2) <> 0 + then invalid_arg "fold2:compare" else + match c1,c2 with + | (DRel, DRel | DNil, DNil | DSort, DSort | DRef _, DRef _) -> acc + | (DCtx (c1,t1), DCtx (c2,t2) + | DApp (c1,t1), DApp (c2,t2) + | DLambda (c1,t1), DLambda (c2,t2)) -> f (f acc c1 c2) t1 t2 + | DCase (ci,p1,c1,bl1),DCase (_,p2,c2,bl2) -> + array_fold_left2 f (f (f acc p1 p2) c1 c2) bl1 bl2 + | DFix (ia,i,ta1,ca1), DFix (_,_,ta2,ca2) -> + array_fold_left2 f (array_fold_left2 f acc ta1 ta2) ca1 ca2 + | DCoFix(i,ta1,ca1), DCoFix(_,ta2,ca2) -> + array_fold_left2 f (array_fold_left2 f acc ta1 ta2) ca1 ca2 + | DCons ((t1,topt1),u1), DCons ((t2,topt2),u2) -> + f (Option.fold_left2 f (f acc t1 t2) topt1 topt2) u1 u2 + | _ -> assert false + + let map2 (f:'a -> 'b -> 'c) (c1:'a t) (c2:'b t) : 'c t = + let head w = map (fun _ -> ()) w in + if compare (head c1) (head c2) <> 0 + then invalid_arg "map2_t:compare" else + match c1,c2 with + | (DRel, DRel | DSort, DSort | DNil, DNil | DRef _, DRef _) as cc -> + let (c,_) = cc in c + | DCtx (c1,t1), DCtx (c2,t2) -> DCtx (f c1 c2, f t1 t2) + | DLambda (t1,c1), DLambda (t2,c2) -> DLambda (f t1 t2, f c1 c2) + | DApp (t1,u1), DApp (t2,u2) -> DApp (f t1 t2,f u1 u2) + | DCase (ci,p1,c1,bl1), DCase (_,p2,c2,bl2) -> + DCase (ci, f p1 p2, f c1 c2, array_map2 f bl1 bl2) + | DFix (ia,i,ta1,ca1), DFix (_,_,ta2,ca2) -> + DFix (ia,i,array_map2 f ta1 ta2,array_map2 f ca1 ca2) + | DCoFix (i,ta1,ca1), DCoFix (_,ta2,ca2) -> + DCoFix (i,array_map2 f ta1 ta2,array_map2 f ca1 ca2) + | DCons ((t1,topt1),u1), DCons ((t2,topt2),u2) -> + DCons ((f t1 t2,Option.lift2 f topt1 topt2), f u1 u2) + | _ -> assert false + + let terminal = function + | (DRel | DSort | DNil | DRef _) -> true + | _ -> false +end + +(* + * Terms discrimination nets + * Uses the general dnet datatype on DTerm.t + * (here you can restart reading) + *) + +(* + * Construction of the module + *) + +module type IDENT = +sig + type t + val compare : t -> t -> int + val subst : substitution -> t -> t + val constr_of : t -> constr +end + +module type OPT = +sig + val reduce : constr -> constr + val direction : bool +end + +module Make = + functor (Ident : IDENT) -> + functor (Opt : OPT) -> +struct + + module TDnet : Dnet.S with type ident=Ident.t + and type 'a structure = 'a DTerm.t + and type meta = metavariable + = Dnet.Make(DTerm)(Ident) + (struct + type t = metavariable + let compare = Pervasives.compare + end) + + type t = TDnet.t + + type ident = TDnet.ident + + type 'a pattern = 'a TDnet.pattern + type term_pattern = term_pattern DTerm.t pattern + + type idset = TDnet.Idset.t + + type result = ident * (constr*existential_key) * Termops.subst + + open DTerm + open TDnet + + let rec pat_of_constr c : term_pattern = + match kind_of_term c with + | Rel _ -> Term DRel + | Sort _ -> Term DSort + | Var i -> Term (DRef (VarRef i)) + | Const c -> Term (DRef (ConstRef c)) + | Ind i -> Term (DRef (IndRef i)) + | Construct c -> Term (DRef (ConstructRef c)) + | Term.Meta _ -> assert false + | Evar (i,_) -> Meta i + | Case (ci,c1,c2,ca) -> + Term(DCase(ci,pat_of_constr c1,pat_of_constr c2,Array.map pat_of_constr ca)) + | Fix ((ia,i),(_,ta,ca)) -> + Term(DFix(ia,i,Array.map pat_of_constr ta, Array.map pat_of_constr ca)) + | CoFix (i,(_,ta,ca)) -> + Term(DCoFix(i,Array.map pat_of_constr ta,Array.map pat_of_constr ca)) + | Cast (c,_,_) -> pat_of_constr c + | Lambda (_,t,c) -> Term(DLambda (pat_of_constr t, pat_of_constr c)) + | (Prod (_,_,_) | LetIn(_,_,_,_)) -> + let (ctx,c) = ctx_of_constr (Term DNil) c in Term (DCtx (ctx,c)) + | App (f,ca) -> + Array.fold_left (fun c a -> Term (DApp (c,a))) + (pat_of_constr f) (Array.map pat_of_constr ca) + + and ctx_of_constr ctx c : term_pattern * term_pattern = + match kind_of_term c with + | Prod (_,t,c) -> ctx_of_constr (Term(DCons((pat_of_constr t,None),ctx))) c + | LetIn(_,d,t,c) -> ctx_of_constr (Term(DCons((pat_of_constr t, Some (pat_of_constr d)),ctx))) c + | _ -> ctx,pat_of_constr c + + let empty_ctx : term_pattern -> term_pattern = function + | Meta _ as c -> c + | Term (DCtx(_,_)) as c -> c + | c -> Term (DCtx (Term DNil, c)) + + (* + * Basic primitives + *) + + let empty = TDnet.empty + + let subst s t = + let sleaf id = Ident.subst s id in + let snode = function + | DTerm.DRef gr -> DTerm.DRef (fst (subst_global s gr)) + | n -> n in + TDnet.map sleaf snode t + + let union = TDnet.union + + let add (c:constr) (id:Ident.t) (dn:t) = + let c = Opt.reduce c in + let c = empty_ctx (pat_of_constr c) in + TDnet.add dn c id + + let new_meta_no = + let ctr = ref 0 in + fun () -> decr ctr; !ctr + + let new_meta_no = Evarutil.new_untyped_evar + + let neutral_meta = new_meta_no() + + let new_meta () = Meta (new_meta_no()) + let new_evar () = mkEvar(new_meta_no(),[||]) + + let rec remove_cap : term_pattern -> term_pattern = function + | Term (DCons (t,u)) -> Term (DCons (t,remove_cap u)) + | Term DNil -> new_meta() + | Meta _ as m -> m + | _ -> assert false + + let under_prod : term_pattern -> term_pattern = function + | Term (DCtx (t,u)) -> Term (DCtx (remove_cap t,u)) + | Meta m -> Term (DCtx(new_meta(), Meta m)) + | _ -> assert false + + let init = let e = new_meta_no() in (mkEvar (e,[||]),e) + + let rec e_subst_evar i (t:unit->constr) c = + match kind_of_term c with + | Evar (j,_) when i=j -> t() + | _ -> map_constr (e_subst_evar i t) c + + let subst_evar i c = e_subst_evar i (fun _ -> c) + + (* debug *) + let rec pr_term_pattern p = + (fun pr_t -> function + | Term t -> pr_t t + | Meta m -> str"["++Util.pr_int (Obj.magic m)++str"]" + ) (pr_dconstr pr_term_pattern) p + + let search_pat cpat dpat dn (up,plug) = + let whole_c = subst_evar plug cpat up in + (* if we are at the root, add an empty context *) + let dpat = if isEvar_or_Meta up then under_prod (empty_ctx dpat) else dpat in + TDnet.Idset.fold + (fun id acc -> + let c_id = Opt.reduce (Ident.constr_of id) in + let (ctx,wc) = + try Termops.align_prod_letin whole_c c_id + with Invalid_argument _ -> [],c_id in + let up = it_mkProd_or_LetIn up ctx in + let wc,whole_c = if Opt.direction then whole_c,wc else wc,whole_c in + try (id,(up,plug),Termops.filtering ctx Reduction.CUMUL wc whole_c)::acc + with Termops.CannotFilter -> (* msgnl(str"recon "++Termops.print_constr_env (Global.env()) wc); *) acc + ) (TDnet.find_match dpat dn) [] + + let fold_pattern_neutral f = + fold_pattern (fun acc (mset,m,dn) -> if m=neutral_meta then acc else f m dn acc) + + let fold_pattern_nonlin f = + let defined = ref Gmap.empty in + fold_pattern_neutral + ( fun m dn acc -> + let dn = try TDnet.inter dn (Gmap.find m !defined) with Not_found -> dn in + defined := Gmap.add m dn !defined; + f m dn acc ) + + let fold_pattern_up f acc dpat cpat dn (up,plug) = + fold_pattern_nonlin + ( fun m dn acc -> + f dn (subst_evar plug (e_subst_evar neutral_meta new_evar cpat) up, m) acc + ) acc dpat dn + + let possibly_under pat k dn (up,plug) = + let rec aux fst dn (up,plug) acc = + let cpat = pat() in + let dpat = pat_of_constr cpat in + let dpat = if fst then under_prod (empty_ctx dpat) else dpat in + (k dn (up,plug)) @ + snd (fold_pattern_up (aux false) acc dpat cpat dn (up,plug)) in + aux true dn (up,plug) [] + + let eq_pat eq () = mkApp(eq,[|mkEvar(neutral_meta,[||]);new_evar();new_evar()|]) + let app_pat () = mkApp(new_evar(),[|mkEvar(neutral_meta,[||])|]) + + (* + * High-level primitives describing specific search problems + *) + + let search_pattern dn pat = + let pat = Opt.reduce pat in + search_pat pat (empty_ctx (pat_of_constr pat)) dn init + + let search_concl dn pat = + let pat = Opt.reduce pat in + search_pat pat (under_prod (empty_ctx (pat_of_constr pat))) dn init + + let search_eq_concl dn eq pat = + let pat = Opt.reduce pat in + let eq_pat = eq_pat eq () in + let eq_dpat = under_prod (empty_ctx (pat_of_constr eq_pat)) in + snd (fold_pattern_up + (fun dn up acc -> + search_pat pat (pat_of_constr pat) dn up @ acc + ) [] eq_dpat eq_pat dn init) + + let search_head_concl dn pat = + let pat = Opt.reduce pat in + possibly_under app_pat (search_pat pat (pat_of_constr pat)) dn init + + let find_all dn = Idset.elements (TDnet.find_all dn) + + let map f dn = TDnet.map f (fun x -> x) dn +end + +module type S = +sig + type t + type ident + + type result = ident * (constr*existential_key) * Termops.subst + + val empty : t + val add : constr -> ident -> t -> t + val union : t -> t -> t + val subst : substitution -> t -> t + val search_pattern : t -> constr -> result list + val search_concl : t -> constr -> result list + val search_head_concl : t -> constr -> result list + val search_eq_concl : t -> constr -> constr -> result list + val find_all : t -> ident list + val map : (ident -> ident) -> t -> t +end |