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Diffstat (limited to 'interp/notation.ml')
| -rw-r--r-- | interp/notation.ml | 277 |
1 files changed, 277 insertions, 0 deletions
diff --git a/interp/notation.ml b/interp/notation.ml index 25772d8fe4..eeee1ca899 100644 --- a/interp/notation.ml +++ b/interp/notation.ml @@ -424,6 +424,283 @@ type numeral_notation_obj = num_ty : Libnames.qualid; (* for warnings / error messages *) warning : numnot_option } +module Numeral = struct +(** * Numeral notation *) + +(** Reduction + + The constr [c] below isn't necessarily well-typed, since we + built it via an [mkApp] of a conversion function on a term + that starts with the right constructor but might be partially + applied. + + At least [c] is known to be evar-free, since it comes from + our own ad-hoc [constr_of_glob] or from conversions such + as [coqint_of_rawnum]. +*) + +let eval_constr env sigma (c : Constr.t) = + let c = EConstr.of_constr c in + let sigma,t = Typing.type_of env sigma c in + let c' = Vnorm.cbv_vm env sigma c t in + EConstr.Unsafe.to_constr c' + +(* For testing with "compute" instead of "vm_compute" : +let eval_constr env sigma (c : Constr.t) = + let c = EConstr.of_constr c in + let c' = Tacred.compute env sigma c in + EConstr.Unsafe.to_constr c' +*) + +let eval_constr_app env sigma c1 c2 = + eval_constr env sigma (mkApp (c1,[| c2 |])) + +exception NotANumber + +let warn_large_num = + CWarnings.create ~name:"large-number" ~category:"numbers" + (fun ty -> + strbrk "Stack overflow or segmentation fault happens when " ++ + strbrk "working with large numbers in " ++ pr_qualid ty ++ + strbrk " (threshold may vary depending" ++ + strbrk " on your system limits and on the command executed).") + +let warn_abstract_large_num = + CWarnings.create ~name:"abstract-large-number" ~category:"numbers" + (fun (ty,f) -> + strbrk "To avoid stack overflow, large numbers in " ++ + pr_qualid ty ++ strbrk " are interpreted as applications of " ++ + Nametab.pr_global_env (Termops.vars_of_env (Global.env ())) f ++ strbrk ".") + +(** Comparing two raw numbers (base 10, big-endian, non-negative). + A bit nasty, but not critical: only used to decide when a + number is considered as large (see warnings above). *) + +exception Comp of int + +let rec rawnum_compare s s' = + let l = String.length s and l' = String.length s' in + if l < l' then - rawnum_compare s' s + else + let d = l-l' in + try + for i = 0 to d-1 do if s.[i] != '0' then raise (Comp 1) done; + for i = d to l-1 do + let c = Pervasives.compare s.[i] s'.[i-d] in + if c != 0 then raise (Comp c) + done; + 0 + with Comp c -> c + +(***********************************************************************) + +(** ** Conversion between Coq [Decimal.int] and internal raw string *) + +(** Decimal.Nil has index 1, then Decimal.D0 has index 2 .. Decimal.D9 is 11 *) + +let digit_of_char c = + assert ('0' <= c && c <= '9'); + Char.code c - Char.code '0' + 2 + +let char_of_digit n = + assert (2<=n && n<=11); + Char.chr (n-2 + Char.code '0') + +let coquint_of_rawnum uint str = + let nil = mkConstruct (uint,1) in + let rec do_chars s i acc = + if i < 0 then acc + else + let dg = mkConstruct (uint, digit_of_char s.[i]) in + do_chars s (i-1) (mkApp(dg,[|acc|])) + in + do_chars str (String.length str - 1) nil + +let coqint_of_rawnum inds (str,sign) = + let uint = coquint_of_rawnum inds.uint str in + mkApp (mkConstruct (inds.int, if sign then 1 else 2), [|uint|]) + +let rawnum_of_coquint c = + let rec of_uint_loop c buf = + match Constr.kind c with + | Construct ((_,1), _) (* Nil *) -> () + | App (c, [|a|]) -> + (match Constr.kind c with + | Construct ((_,n), _) (* D0 to D9 *) -> + let () = Buffer.add_char buf (char_of_digit n) in + of_uint_loop a buf + | _ -> raise NotANumber) + | _ -> raise NotANumber + in + let buf = Buffer.create 64 in + let () = of_uint_loop c buf in + if Int.equal (Buffer.length buf) 0 then + (* To avoid ambiguities between Nil and (D0 Nil), we choose + to not display Nil alone as "0" *) + raise NotANumber + else Buffer.contents buf + +let rawnum_of_coqint c = + match Constr.kind c with + | App (c,[|c'|]) -> + (match Constr.kind c with + | Construct ((_,1), _) (* Pos *) -> (rawnum_of_coquint c', true) + | Construct ((_,2), _) (* Neg *) -> (rawnum_of_coquint c', false) + | _ -> raise NotANumber) + | _ -> raise NotANumber + + +(***********************************************************************) + +(** ** Conversion between Coq [Z] and internal bigint *) + +(** First, [positive] from/to bigint *) + +let rec pos_of_bigint posty n = + match Bigint.div2_with_rest n with + | (q, false) -> + let c = mkConstruct (posty, 2) in (* xO *) + mkApp (c, [| pos_of_bigint posty q |]) + | (q, true) when not (Bigint.equal q Bigint.zero) -> + let c = mkConstruct (posty, 1) in (* xI *) + mkApp (c, [| pos_of_bigint posty q |]) + | (q, true) -> + mkConstruct (posty, 3) (* xH *) + +let rec bigint_of_pos c = match Constr.kind c with + | Construct ((_, 3), _) -> (* xH *) Bigint.one + | App (c, [| d |]) -> + begin match Constr.kind c with + | Construct ((_, n), _) -> + begin match n with + | 1 -> (* xI *) Bigint.add_1 (Bigint.mult_2 (bigint_of_pos d)) + | 2 -> (* xO *) Bigint.mult_2 (bigint_of_pos d) + | n -> assert false (* no other constructor of type positive *) + end + | x -> raise NotANumber + end + | x -> raise NotANumber + +(** Now, [Z] from/to bigint *) + +let z_of_bigint { z_ty; pos_ty } n = + if Bigint.equal n Bigint.zero then + mkConstruct (z_ty, 1) (* Z0 *) + else + let (s, n) = + if Bigint.is_pos_or_zero n then (2, n) (* Zpos *) + else (3, Bigint.neg n) (* Zneg *) + in + let c = mkConstruct (z_ty, s) in + mkApp (c, [| pos_of_bigint pos_ty n |]) + +let bigint_of_z z = match Constr.kind z with + | Construct ((_, 1), _) -> (* Z0 *) Bigint.zero + | App (c, [| d |]) -> + begin match Constr.kind c with + | Construct ((_, n), _) -> + begin match n with + | 2 -> (* Zpos *) bigint_of_pos d + | 3 -> (* Zneg *) Bigint.neg (bigint_of_pos d) + | n -> assert false (* no other constructor of type Z *) + end + | _ -> raise NotANumber + end + | _ -> raise NotANumber + +(** The uninterp function below work at the level of [glob_constr] + which is too low for us here. So here's a crude conversion back + to [constr] for the subset that concerns us. *) + +let rec constr_of_glob env sigma g = match DAst.get g with + | Glob_term.GRef (ConstructRef c, _) -> + let sigma,c = Evd.fresh_constructor_instance env sigma c in + sigma,mkConstructU c + | Glob_term.GApp (gc, gcl) -> + let sigma,c = constr_of_glob env sigma gc in + let sigma,cl = List.fold_left_map (constr_of_glob env) sigma gcl in + sigma,mkApp (c, Array.of_list cl) + | _ -> + raise NotANumber + +let rec glob_of_constr ?loc env sigma c = match Constr.kind c with + | App (c, ca) -> + let c = glob_of_constr ?loc env sigma c in + let cel = List.map (glob_of_constr ?loc env sigma) (Array.to_list ca) in + DAst.make ?loc (Glob_term.GApp (c, cel)) + | Construct (c, _) -> DAst.make ?loc (Glob_term.GRef (ConstructRef c, None)) + | Const (c, _) -> DAst.make ?loc (Glob_term.GRef (ConstRef c, None)) + | Ind (ind, _) -> DAst.make ?loc (Glob_term.GRef (IndRef ind, None)) + | Var id -> DAst.make ?loc (Glob_term.GRef (VarRef id, None)) + | _ -> Loc.raise ?loc (NumeralNotationError(env,sigma,UnexpectedTerm c)) + +let no_such_number ?loc ty = + CErrors.user_err ?loc + (str "Cannot interpret this number as a value of type " ++ + pr_qualid ty) + +let interp_option ty ?loc env sigma c = + match Constr.kind c with + | App (_Some, [| _; c |]) -> glob_of_constr ?loc env sigma c + | App (_None, [| _ |]) -> no_such_number ?loc ty + | x -> Loc.raise ?loc (NumeralNotationError(env,sigma,UnexpectedNonOptionTerm c)) + +let uninterp_option c = + match Constr.kind c with + | App (_Some, [| _; x |]) -> x + | _ -> raise NotANumber + +let big2raw n = + if Bigint.is_pos_or_zero n then (Bigint.to_string n, true) + else (Bigint.to_string (Bigint.neg n), false) + +let raw2big (n,s) = + if s then Bigint.of_string n else Bigint.neg (Bigint.of_string n) + +let interp o ?loc n = + begin match o.warning with + | Warning threshold when snd n && rawnum_compare (fst n) threshold >= 0 -> + warn_large_num o.num_ty + | _ -> () + end; + let c = match fst o.to_kind with + | Int int_ty -> coqint_of_rawnum int_ty n + | UInt uint_ty when snd n -> coquint_of_rawnum uint_ty (fst n) + | UInt _ (* n <= 0 *) -> no_such_number ?loc o.num_ty + | Z z_pos_ty -> z_of_bigint z_pos_ty (raw2big n) + in + let env = Global.env () in + let sigma = Evd.from_env env in + let sigma,to_ty = Evd.fresh_global env sigma o.to_ty in + let to_ty = EConstr.Unsafe.to_constr to_ty in + match o.warning, snd o.to_kind with + | Abstract threshold, Direct when rawnum_compare (fst n) threshold >= 0 -> + warn_abstract_large_num (o.num_ty,o.to_ty); + glob_of_constr ?loc env sigma (mkApp (to_ty,[|c|])) + | _ -> + let res = eval_constr_app env sigma to_ty c in + match snd o.to_kind with + | Direct -> glob_of_constr ?loc env sigma res + | Option -> interp_option o.num_ty ?loc env sigma res + +let uninterp o (Glob_term.AnyGlobConstr n) = + let env = Global.env () in + let sigma = Evd.from_env env in + let sigma,of_ty = Evd.fresh_global env sigma o.of_ty in + let of_ty = EConstr.Unsafe.to_constr of_ty in + try + let sigma,n = constr_of_glob env sigma n in + let c = eval_constr_app env sigma of_ty n in + let c = if snd o.of_kind == Direct then c else uninterp_option c in + match fst o.of_kind with + | Int _ -> Some (rawnum_of_coqint c) + | UInt _ -> Some (rawnum_of_coquint c, true) + | Z _ -> Some (big2raw (bigint_of_z c)) + with + | Type_errors.TypeError _ | Pretype_errors.PretypeError _ -> None (* cf. eval_constr_app *) + | NotANumber -> None (* all other functions except big2raw *) +end + (* Table from scope_name to backtrack-able informations about interpreters (in particular interpreter unique id). *) let prim_token_interp_infos = |
