src/Tools/nbe.ML
author haftmann
Thu May 07 16:22:35 2009 +0200 (2009-05-07)
changeset 31064 ce37d8f48a9f
parent 31049 396d4d6a1594
child 31156 90fed3d4430f
permissions -rw-r--r--
treat frees driectly by the LCF kernel
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(*  Title:      Tools/nbe.ML
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    Authors:    Klaus Aehlig, LMU Muenchen; Tobias Nipkow, Florian Haftmann, TU Muenchen
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Normalization by evaluation, based on generic code generator.
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*)
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signature NBE =
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sig
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  val norm_conv: cterm -> thm
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  val norm: theory -> term -> term
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  datatype Univ =
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      Const of int * Univ list               (*named (uninterpreted) constants*)
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    | DFree of string * int                  (*free (uninterpreted) dictionary parameters*)
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    | BVar of int * Univ list
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    | Abs of (int * (Univ list -> Univ)) * Univ list
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  val apps: Univ -> Univ list -> Univ        (*explicit applications*)
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  val abss: int -> (Univ list -> Univ) -> Univ
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                                             (*abstractions as closures*)
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  val same: Univ -> Univ -> bool
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  val univs_ref: (unit -> Univ list -> Univ list) option ref
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  val trace: bool ref
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  val setup: theory -> theory
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end;
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structure Nbe: NBE =
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struct
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(* generic non-sense *)
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val trace = ref false;
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fun tracing f x = if !trace then (Output.tracing (f x); x) else x;
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(** the semantical universe **)
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(*
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   Functions are given by their semantical function value. To avoid
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   trouble with the ML-type system, these functions have the most
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   generic type, that is "Univ list -> Univ". The calling convention is
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   that the arguments come as a list, the last argument first. In
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   other words, a function call that usually would look like
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   f x_1 x_2 ... x_n   or   f(x_1,x_2, ..., x_n)
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   would be in our convention called as
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              f [x_n,..,x_2,x_1]
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   Moreover, to handle functions that are still waiting for some
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   arguments we have additionally a list of arguments collected to far
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   and the number of arguments we're still waiting for.
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*)
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datatype Univ =
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    Const of int * Univ list           (*named (uninterpreted) constants*)
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  | DFree of string * int              (*free (uninterpreted) dictionary parameters*)
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  | BVar of int * Univ list            (*bound variables, named*)
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  | Abs of (int * (Univ list -> Univ)) * Univ list
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                                       (*abstractions as closures*);
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fun same (Const (k, xs)) (Const (l, ys)) = k = l andalso sames xs ys
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  | same (DFree (s, k)) (DFree (t, l)) = s = t andalso k = l
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  | same (BVar (k, xs)) (BVar (l, ys)) = k = l andalso sames xs ys
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  | same _ _ = false
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and sames xs ys = length xs = length ys andalso forall (uncurry same) (xs ~~ ys);
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(* constructor functions *)
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fun abss n f = Abs ((n, f), []);
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fun apps (Abs ((n, f), xs)) ys = let val k = n - length ys in
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      case int_ord (k, 0)
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       of EQUAL => f (ys @ xs)
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        | LESS => let val (zs, ws) = chop (~ k) ys in apps (f (ws @ xs)) zs end
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        | GREATER => Abs ((k, f), ys @ xs) (*note: reverse convention also for apps!*)
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      end
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  | apps (Const (name, xs)) ys = Const (name, ys @ xs)
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  | apps (BVar (n, xs)) ys = BVar (n, ys @ xs);
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(** assembling and compiling ML code from terms **)
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(* abstract ML syntax *)
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infix 9 `$` `$$`;
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fun e1 `$` e2 = "(" ^ e1 ^ " " ^ e2 ^ ")";
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fun e `$$` [] = e
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  | e `$$` es = "(" ^ e ^ " " ^ space_implode " " es ^ ")";
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fun ml_abs v e = "(fn " ^ v ^ " => " ^ e ^ ")";
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fun ml_cases t cs =
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  "(case " ^ t ^ " of " ^ space_implode " | " (map (fn (p, t) => p ^ " => " ^ t) cs) ^ ")";
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fun ml_Let d e = "let\n" ^ d ^ " in " ^ e ^ " end";
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fun ml_as v t = "(" ^ v ^ " as " ^ t ^ ")";
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fun ml_and [] = "true"
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  | ml_and [x] = x
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  | ml_and xs = "(" ^ space_implode " andalso " xs ^ ")";
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fun ml_if b x y = "(if " ^ b ^ " then " ^ x ^ " else " ^ y ^ ")";
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fun ml_list es = "[" ^ commas es ^ "]";
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fun ml_fundefs ([(name, [([], e)])]) =
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      "val " ^ name ^ " = " ^ e ^ "\n"
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  | ml_fundefs (eqs :: eqss) =
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      let
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        fun fundef (name, eqs) =
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          let
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            fun eqn (es, e) = name ^ " " ^ space_implode " " es ^ " = " ^ e
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          in space_implode "\n  | " (map eqn eqs) end;
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      in
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        (prefix "fun " o fundef) eqs :: map (prefix "and " o fundef) eqss
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        |> cat_lines
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        |> suffix "\n"
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      end;
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(* nbe specific syntax and sandbox communication *)
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val univs_ref = ref (NONE : (unit -> Univ list -> Univ list) option);
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local
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  val prefix =      "Nbe.";
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  val name_ref =    prefix ^ "univs_ref";
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  val name_const =  prefix ^ "Const";
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  val name_abss =   prefix ^ "abss";
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  val name_apps =   prefix ^ "apps";
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  val name_same =   prefix ^ "same";
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in
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val univs_cookie = (name_ref, univs_ref);
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fun nbe_fun 0 "" = "nbe_value"
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  | nbe_fun i c = "c_" ^ translate_string (fn "." => "_" | c => c) c ^ "_" ^ string_of_int i;
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fun nbe_dict v n = "d_" ^ v ^ "_" ^ string_of_int n;
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fun nbe_bound v = "v_" ^ v;
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fun nbe_default v = "w_" ^ v;
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(*note: these three are the "turning spots" where proper argument order is established!*)
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fun nbe_apps t [] = t
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  | nbe_apps t ts = name_apps `$$` [t, ml_list (rev ts)];
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fun nbe_apps_local i c ts = nbe_fun i c `$` ml_list (rev ts);
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fun nbe_apps_constr idx_of c ts =
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  let
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    val c' = if !trace then string_of_int (idx_of c) ^ " (*" ^ c ^ "*)"
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      else string_of_int (idx_of c);
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  in name_const `$` ("(" ^ c' ^ ", " ^ ml_list (rev ts) ^ ")") end;
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fun nbe_abss 0 f = f `$` ml_list []
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  | nbe_abss n f = name_abss `$$` [string_of_int n, f];
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fun nbe_same v1 v2 = "(" ^ name_same ^ " " ^ nbe_bound v1 ^ " " ^ nbe_bound v2 ^ ")";
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end;
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open Basic_Code_Thingol;
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(* code generation *)
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fun assemble_eqnss idx_of deps eqnss =
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  let
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    fun prep_eqns (c, (vs, eqns)) =
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      let
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        val dicts = maps (fn (v, sort) => map_index (nbe_dict v o fst) sort) vs;
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        val num_args = length dicts + ((length o fst o hd) eqns);
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      in (c, (num_args, (dicts, eqns))) end;
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    val eqnss' = map prep_eqns eqnss;
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    fun assemble_constapp c dss ts = 
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      let
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        val ts' = (maps o map) assemble_idict dss @ ts;
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      in case AList.lookup (op =) eqnss' c
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       of SOME (num_args, _) => if num_args <= length ts'
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            then let val (ts1, ts2) = chop num_args ts'
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            in nbe_apps (nbe_apps_local 0 c ts1) ts2
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            end else nbe_apps (nbe_abss num_args (nbe_fun 0 c)) ts'
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        | NONE => if member (op =) deps c
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            then nbe_apps (nbe_fun 0 c) ts'
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            else nbe_apps_constr idx_of c ts'
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      end
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    and assemble_idict (DictConst (inst, dss)) =
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          assemble_constapp inst dss []
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      | assemble_idict (DictVar (supers, (v, (n, _)))) =
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          fold_rev (fn super => assemble_constapp super [] o single) supers (nbe_dict v n);
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    fun assemble_iterm constapp =
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      let
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        fun of_iterm match_cont t =
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          let
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            val (t', ts) = Code_Thingol.unfold_app t
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          in of_iapp match_cont t' (fold_rev (cons o of_iterm NONE) ts []) end
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        and of_iapp match_cont (IConst (c, ((_, dss), _))) ts = constapp c dss ts
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          | of_iapp match_cont (IVar v) ts = nbe_apps (nbe_bound v) ts
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          | of_iapp match_cont ((v, _) `|-> t) ts =
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              nbe_apps (nbe_abss 1 (ml_abs (ml_list [nbe_bound v]) (of_iterm NONE t))) ts
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          | of_iapp match_cont (ICase (((t, _), cs), t0)) ts =
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              nbe_apps (ml_cases (of_iterm NONE t)
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                (map (fn (p, t) => (of_iterm NONE p, of_iterm match_cont t)) cs
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                  @ [("_", case match_cont of SOME s => s | NONE => of_iterm NONE t0)])) ts
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      in of_iterm end;
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    fun subst_nonlin_vars args =
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      let
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        val vs = (fold o Code_Thingol.fold_varnames)
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          (fn v => AList.map_default (op =) (v, 0) (curry (op +) 1)) args [];
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        val names = Name.make_context (map fst vs);
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        fun declare v k ctxt = let val vs = Name.invents ctxt v k
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          in (vs, fold Name.declare vs ctxt) end;
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        val (vs_renames, _) = fold_map (fn (v, k) => if k > 1
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          then declare v (k - 1) #>> (fn vs => (v, vs))
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          else pair (v, [])) vs names;
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        val samepairs = maps (fn (v, vs) => map (pair v) vs) vs_renames;
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        fun subst_vars (t as IConst _) samepairs = (t, samepairs)
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          | subst_vars (t as IVar v) samepairs = (case AList.lookup (op =) samepairs v
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             of SOME v' => (IVar v', AList.delete (op =) v samepairs)
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              | NONE => (t, samepairs))
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          | subst_vars (t1 `$ t2) samepairs = samepairs
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              |> subst_vars t1
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              ||>> subst_vars t2
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              |>> (op `$)
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          | subst_vars (ICase (_, t)) samepairs = subst_vars t samepairs;
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        val (args', _) = fold_map subst_vars args samepairs;
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      in (samepairs, args') end;
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    fun assemble_eqn c dicts default_args (i, (args, rhs)) =
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      let
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        val is_eval = (c = "");
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        val default_rhs = nbe_apps_local (i+1) c (dicts @ default_args);
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        val match_cont = if is_eval then NONE else SOME default_rhs;
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        val assemble_arg = assemble_iterm
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          (fn c => fn _ => fn ts => nbe_apps_constr idx_of c ts) NONE;
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        val assemble_rhs = assemble_iterm assemble_constapp match_cont ;
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        val (samepairs, args') = subst_nonlin_vars args;
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        val s_args = map assemble_arg args';
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        val s_rhs = if null samepairs then assemble_rhs rhs
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          else ml_if (ml_and (map (uncurry nbe_same) samepairs))
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            (assemble_rhs rhs) default_rhs;
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        val eqns = if is_eval then
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            [([ml_list (rev (dicts @ s_args))], s_rhs)]
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          else
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            [([ml_list (rev (dicts @ map2 ml_as default_args s_args))], s_rhs),
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              ([ml_list (rev (dicts @ default_args))], default_rhs)]
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      in (nbe_fun i c, eqns) end;
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    fun assemble_eqns (c, (num_args, (dicts, eqns))) =
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      let
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        val default_args = map nbe_default
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          (Name.invent_list [] "a" (num_args - length dicts));
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        val eqns' = map_index (assemble_eqn c dicts default_args) eqns
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          @ (if c = "" then [] else [(nbe_fun (length eqns) c,
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            [([ml_list (rev (dicts @ default_args))],
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              nbe_apps_constr idx_of c (dicts @ default_args))])]);
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      in (eqns', nbe_abss num_args (nbe_fun 0 c)) end;
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    val (fun_vars, fun_vals) = map_split assemble_eqns eqnss';
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    val deps_vars = ml_list (map (nbe_fun 0) deps);
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  in ml_abs deps_vars (ml_Let (ml_fundefs (flat fun_vars)) (ml_list fun_vals)) end;
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(* code compilation *)
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fun compile_eqnss _ gr raw_deps [] = []
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  | compile_eqnss ctxt gr raw_deps eqnss =
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      let
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        val (deps, deps_vals) = split_list (map_filter
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          (fn dep => Option.map (fn univ => (dep, univ)) (fst ((Graph.get_node gr dep)))) raw_deps);
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        val idx_of = raw_deps
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          |> map (fn dep => (dep, snd (Graph.get_node gr dep)))
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          |> AList.lookup (op =)
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          |> (fn f => the o f);
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        val s = assemble_eqnss idx_of deps eqnss;
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        val cs = map fst eqnss;
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      in
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        s
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        |> tracing (fn s => "\n--- code to be evaluated:\n" ^ s)
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        |> ML_Context.evaluate ctxt (!trace) univs_cookie
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        |> (fn f => f deps_vals)
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        |> (fn univs => cs ~~ univs)
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      end;
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(* preparing function equations *)
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fun eqns_of_stmt (_, Code_Thingol.Fun (_, (_, []))) =
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      []
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  | eqns_of_stmt (const, Code_Thingol.Fun (_, ((vs, _), eqns))) =
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      [(const, (vs, map fst eqns))]
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  | eqns_of_stmt (_, Code_Thingol.Datatypecons _) =
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      []
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  | eqns_of_stmt (_, Code_Thingol.Datatype _) =
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      []
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  | eqns_of_stmt (class, Code_Thingol.Class (_, (v, (superclasses, classops)))) =
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      let
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        val names = map snd superclasses @ map fst classops;
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        val params = Name.invent_list [] "d" (length names);
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        fun mk (k, name) =
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          (name, ([(v, [])],
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            [([IConst (class, (([], []), [])) `$$ map IVar params], IVar (nth params k))]));
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      in map_index mk names end
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  | eqns_of_stmt (_, Code_Thingol.Classrel _) =
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      []
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  | eqns_of_stmt (_, Code_Thingol.Classparam _) =
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      []
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  | eqns_of_stmt (inst, Code_Thingol.Classinst ((class, (_, arities)), (superinsts, instops))) =
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   305
      [(inst, (arities, [([], IConst (class, (([], []), [])) `$$
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   306
        map (fn (_, (_, (inst, dicts))) => IConst (inst, (([], dicts), []))) superinsts
haftmann@25101
   307
        @ map (IConst o snd o fst) instops)]))];
haftmann@24155
   308
wenzelm@28274
   309
fun compile_stmts ctxt stmts_deps =
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   310
  let
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   311
    val names = map (fst o fst) stmts_deps;
haftmann@25101
   312
    val names_deps = map (fn ((name, _), deps) => (name, deps)) stmts_deps;
haftmann@25101
   313
    val eqnss = maps (eqns_of_stmt o fst) stmts_deps;
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   314
    val refl_deps = names_deps
haftmann@25190
   315
      |> maps snd
haftmann@25190
   316
      |> distinct (op =)
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   317
      |> fold (insert (op =)) names;
haftmann@26064
   318
    fun new_node name (gr, (maxidx, idx_tab)) = if can (Graph.get_node gr) name
haftmann@26064
   319
      then (gr, (maxidx, idx_tab))
haftmann@26064
   320
      else (Graph.new_node (name, (NONE, maxidx)) gr,
haftmann@26064
   321
        (maxidx + 1, Inttab.update_new (maxidx, name) idx_tab));
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   322
    fun compile gr = eqnss
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   323
      |> compile_eqnss ctxt gr refl_deps
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   324
      |> rpair gr;
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   325
  in
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   326
    fold new_node refl_deps
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   327
    #> apfst (fold (fn (name, deps) => fold (curry Graph.add_edge name) deps) names_deps
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   328
      #> compile
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   329
      #-> fold (fn (name, univ) => (Graph.map_node name o apfst) (K (SOME univ))))
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   330
  end;
haftmann@24155
   331
haftmann@28706
   332
fun ensure_stmts ctxt naming program =
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   333
  let
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   334
    fun add_stmts names (gr, (maxidx, idx_tab)) = if exists ((can o Graph.get_node) gr) names
haftmann@26064
   335
      then (gr, (maxidx, idx_tab))
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   336
      else (gr, (maxidx, idx_tab))
wenzelm@28274
   337
        |> compile_stmts ctxt (map (fn name => ((name, Graph.get_node program name),
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   338
          Graph.imm_succs program name)) names);
haftmann@28706
   339
  in
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   340
    fold_rev add_stmts (Graph.strong_conn program)
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   341
    #> pair naming
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   342
  end;
haftmann@24155
   343
haftmann@25944
   344
haftmann@25944
   345
(** evaluation **)
haftmann@25944
   346
haftmann@25944
   347
(* term evaluation *)
haftmann@25944
   348
haftmann@30947
   349
fun eval_term ctxt gr deps (vs : (string * sort) list, t) =
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   350
  let 
haftmann@25924
   351
    val dict_frees = maps (fn (v, sort) => map_index (curry DFree v o fst) sort) vs;
haftmann@25924
   352
  in
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   353
    ("", (vs, [([], t)]))
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   354
    |> singleton (compile_eqnss ctxt gr deps)
haftmann@25924
   355
    |> snd
haftmann@31064
   356
    |> (fn t => apps t (rev dict_frees))
haftmann@25924
   357
  end;
haftmann@24155
   358
haftmann@24839
   359
(* reification *)
haftmann@24155
   360
haftmann@30947
   361
fun typ_of_itype program vs (ityco `%% itys) =
haftmann@30947
   362
      let
haftmann@30947
   363
        val Code_Thingol.Datatype (tyco, _) = Graph.get_node program ityco;
haftmann@30947
   364
      in Type (tyco, map (typ_of_itype program vs) itys) end
haftmann@30947
   365
  | typ_of_itype program vs (ITyVar v) =
haftmann@30947
   366
      let
haftmann@30947
   367
        val sort = (the o AList.lookup (op =) vs) v;
haftmann@30947
   368
      in TFree ("'" ^ v, sort) end;
haftmann@30947
   369
haftmann@28663
   370
fun term_of_univ thy program idx_tab t =
haftmann@24155
   371
  let
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   372
    fun take_until f [] = []
haftmann@25101
   373
      | take_until f (x::xs) = if f x then [] else x :: take_until f xs;
haftmann@28663
   374
    fun is_dict (Const (idx, _)) = (case (Graph.get_node program o the o Inttab.lookup idx_tab) idx
haftmann@28663
   375
         of Code_Thingol.Class _ => true
haftmann@28663
   376
          | Code_Thingol.Classrel _ => true
haftmann@28663
   377
          | Code_Thingol.Classinst _ => true
haftmann@28663
   378
          | _ => false)
haftmann@25101
   379
      | is_dict (DFree _) = true
haftmann@25101
   380
      | is_dict _ = false;
haftmann@28663
   381
    fun const_of_idx idx = (case (Graph.get_node program o the o Inttab.lookup idx_tab) idx
haftmann@28663
   382
         of Code_Thingol.Fun (c, _) => c
haftmann@28663
   383
          | Code_Thingol.Datatypecons (c, _) => c
haftmann@28663
   384
          | Code_Thingol.Classparam (c, _) => c);
haftmann@24155
   385
    fun of_apps bounds (t, ts) =
haftmann@24155
   386
      fold_map (of_univ bounds) ts
haftmann@24155
   387
      #>> (fn ts' => list_comb (t, rev ts'))
haftmann@26064
   388
    and of_univ bounds (Const (idx, ts)) typidx =
haftmann@24155
   389
          let
haftmann@25101
   390
            val ts' = take_until is_dict ts;
haftmann@28663
   391
            val c = const_of_idx idx;
haftmann@28423
   392
            val (_, T) = Code.default_typscheme thy c;
haftmann@30022
   393
            val T' = map_type_tfree (fn (v, _) => TypeInfer.param typidx (v, [])) T;
haftmann@30022
   394
            val typidx' = typidx + 1;
haftmann@25101
   395
          in of_apps bounds (Term.Const (c, T'), ts') typidx' end
haftmann@27499
   396
      | of_univ bounds (BVar (n, ts)) typidx =
haftmann@27499
   397
          of_apps bounds (Bound (bounds - n - 1), ts) typidx
haftmann@24155
   398
      | of_univ bounds (t as Abs _) typidx =
haftmann@24155
   399
          typidx
haftmann@25924
   400
          |> of_univ (bounds + 1) (apps t [BVar (bounds, [])])
haftmann@24155
   401
          |-> (fn t' => pair (Term.Abs ("u", dummyT, t')))
haftmann@24155
   402
  in of_univ 0 t 0 |> fst end;
haftmann@24155
   403
haftmann@25101
   404
(* function store *)
haftmann@25101
   405
haftmann@25101
   406
structure Nbe_Functions = CodeDataFun
haftmann@25101
   407
(
haftmann@28706
   408
  type T = Code_Thingol.naming * ((Univ option * int) Graph.T * (int * string Inttab.table));
haftmann@28706
   409
  val empty = (Code_Thingol.empty_naming, (Graph.empty, (0, Inttab.empty)));
haftmann@28706
   410
  fun purge thy cs (naming, (gr, (maxidx, idx_tab))) =
haftmann@27609
   411
    let
haftmann@28706
   412
      val names_delete = cs
haftmann@28706
   413
        |> map_filter (Code_Thingol.lookup_const naming)
haftmann@28706
   414
        |> filter (can (Graph.get_node gr))
haftmann@28706
   415
        |> Graph.all_preds gr;
haftmann@28706
   416
      val gr' = Graph.del_nodes names_delete gr;
haftmann@28706
   417
    in (naming, (gr', (maxidx, idx_tab))) end;
haftmann@25101
   418
);
haftmann@25101
   419
haftmann@25101
   420
(* compilation, evaluation and reification *)
haftmann@25101
   421
haftmann@30947
   422
fun compile_eval thy naming program vs_t deps =
haftmann@26064
   423
  let
wenzelm@28274
   424
    val ctxt = ProofContext.init thy;
haftmann@28706
   425
    val (_, (gr, (_, idx_tab))) =
haftmann@28706
   426
      Nbe_Functions.change thy (ensure_stmts ctxt naming program o snd);
haftmann@26064
   427
  in
haftmann@30947
   428
    vs_t
wenzelm@28274
   429
    |> eval_term ctxt gr deps
haftmann@28663
   430
    |> term_of_univ thy program idx_tab
haftmann@26064
   431
  end;
haftmann@25101
   432
haftmann@24155
   433
(* evaluation with type reconstruction *)
haftmann@24155
   434
haftmann@31064
   435
fun normalize thy naming program ((vs0, (vs, ty)), t) deps =
haftmann@24155
   436
  let
haftmann@26747
   437
    fun subst_const f = map_aterms (fn t as Term.Const (c, ty) => Term.Const (f c, ty)
haftmann@26747
   438
      | t => t);
haftmann@30947
   439
    val resubst_triv_consts = subst_const (Code_Unit.resubst_alias thy);
haftmann@30947
   440
    val ty' = typ_of_itype program vs0 ty;
wenzelm@27264
   441
    fun type_infer t =
wenzelm@27264
   442
      singleton (TypeInfer.infer_types (Syntax.pp_global thy) (Sign.tsig_of thy) I
wenzelm@27264
   443
        (try (Type.strip_sorts o Sign.the_const_type thy)) (K NONE) Name.context 0)
haftmann@30947
   444
      (TypeInfer.constrain ty' t);
wenzelm@29272
   445
    fun check_tvars t = if null (Term.add_tvars t []) then t else
haftmann@24155
   446
      error ("Illegal schematic type variables in normalized term: "
wenzelm@26952
   447
        ^ setmp show_types true (Syntax.string_of_term_global thy) t);
wenzelm@26952
   448
    val string_of_term = setmp show_types true (Syntax.string_of_term_global thy);
haftmann@24155
   449
  in
haftmann@30947
   450
    compile_eval thy naming program (vs, t) deps
haftmann@25167
   451
    |> tracing (fn t => "Normalized:\n" ^ string_of_term t)
haftmann@30947
   452
    |> resubst_triv_consts
haftmann@26739
   453
    |> type_infer
haftmann@25167
   454
    |> tracing (fn t => "Types inferred:\n" ^ string_of_term t)
haftmann@26739
   455
    |> check_tvars
haftmann@25101
   456
    |> tracing (fn t => "---\n")
haftmann@24155
   457
  end;
haftmann@24155
   458
haftmann@24155
   459
(* evaluation oracle *)
haftmann@24155
   460
haftmann@30947
   461
fun add_triv_classes thy = curry (Sorts.inter_sort (Sign.classes_of thy))
haftmann@30947
   462
  (Code_Unit.triv_classes thy);
haftmann@30947
   463
haftmann@30947
   464
fun mk_equals thy lhs raw_rhs =
haftmann@26747
   465
  let
haftmann@30947
   466
    val ty = Thm.typ_of (Thm.ctyp_of_term lhs);
haftmann@30947
   467
    val eq = Thm.cterm_of thy (Term.Const ("==", ty --> ty --> propT));
haftmann@30947
   468
    val rhs = Thm.cterm_of thy raw_rhs;
haftmann@30947
   469
  in Thm.mk_binop eq lhs rhs end;
haftmann@26747
   470
haftmann@30942
   471
val (_, raw_norm_oracle) = Context.>>> (Context.map_theory_result
haftmann@31064
   472
  (Thm.add_oracle (Binding.name "norm", fn (thy, naming, program, vsp_ty_t, deps, ct) =>
haftmann@31064
   473
    mk_equals thy ct (normalize thy naming program vsp_ty_t deps))));
haftmann@31064
   474
haftmann@31064
   475
fun norm_oracle thy naming program vsp_ty_t deps ct =
haftmann@31064
   476
  raw_norm_oracle (thy, naming, program, vsp_ty_t, deps, ct);
haftmann@30942
   477
haftmann@31064
   478
fun no_frees_conv conv ct =
haftmann@31064
   479
  let
haftmann@31064
   480
    val frees = Thm.add_cterm_frees ct [];
haftmann@31064
   481
    fun apply_beta free thm = Thm.combination thm (Thm.reflexive free)
haftmann@31064
   482
      |> Conv.fconv_rule (Conv.arg_conv (Conv.try_conv (Thm.beta_conversion false)))
haftmann@31064
   483
      |> Conv.fconv_rule (Conv.arg1_conv (Thm.beta_conversion false));
haftmann@31064
   484
  in
haftmann@31064
   485
    ct
haftmann@31064
   486
    |> fold_rev Thm.cabs frees
haftmann@31064
   487
    |> conv
haftmann@31064
   488
    |> fold apply_beta frees
haftmann@31064
   489
  end;
haftmann@30942
   490
haftmann@31064
   491
fun no_frees_rew rew t =
haftmann@31064
   492
  let
haftmann@31064
   493
    val frees = map Free (Term.add_frees t []);
haftmann@31064
   494
  in
haftmann@31064
   495
    t
haftmann@31064
   496
    |> fold_rev lambda frees
haftmann@31064
   497
    |> rew
haftmann@31064
   498
    |> (fn t' => Term.betapplys (t', frees))
haftmann@31064
   499
  end;
haftmann@31064
   500
haftmann@31064
   501
val norm_conv = no_frees_conv (fn ct =>
haftmann@24155
   502
  let
haftmann@24155
   503
    val thy = Thm.theory_of_cterm ct;
haftmann@31064
   504
  in Code_Thingol.eval_conv thy (add_triv_classes thy) (norm_oracle thy) ct end);
haftmann@24155
   505
haftmann@31064
   506
fun norm thy = no_frees_rew (Code_Thingol.eval thy (add_triv_classes thy) I (normalize thy));
haftmann@24839
   507
haftmann@24155
   508
(* evaluation command *)
haftmann@24155
   509
haftmann@24155
   510
fun norm_print_term ctxt modes t =
haftmann@24155
   511
  let
haftmann@24155
   512
    val thy = ProofContext.theory_of ctxt;
haftmann@30970
   513
    val t' = norm thy t;
haftmann@24839
   514
    val ty' = Term.type_of t';
wenzelm@26952
   515
    val ctxt' = Variable.auto_fixes t ctxt;
wenzelm@24634
   516
    val p = PrintMode.with_modes modes (fn () =>
wenzelm@26952
   517
      Pretty.block [Pretty.quote (Syntax.pretty_term ctxt' t'), Pretty.fbrk,
wenzelm@26952
   518
        Pretty.str "::", Pretty.brk 1, Pretty.quote (Syntax.pretty_typ ctxt' ty')]) ();
haftmann@24155
   519
  in Pretty.writeln p end;
haftmann@24155
   520
haftmann@24155
   521
haftmann@24155
   522
(** Isar setup **)
haftmann@24155
   523
wenzelm@24508
   524
fun norm_print_term_cmd (modes, s) state =
haftmann@24155
   525
  let val ctxt = Toplevel.context_of state
wenzelm@24508
   526
  in norm_print_term ctxt modes (Syntax.read_term ctxt s) end;
haftmann@24155
   527
haftmann@30970
   528
val setup = Value.add_evaluator ("nbe", norm o ProofContext.theory_of);
haftmann@24155
   529
haftmann@24155
   530
local structure P = OuterParse and K = OuterKeyword in
haftmann@24155
   531
haftmann@24155
   532
val opt_modes = Scan.optional (P.$$$ "(" |-- P.!!! (Scan.repeat1 P.xname --| P.$$$ ")")) [];
haftmann@24155
   533
wenzelm@24867
   534
val _ =
haftmann@24155
   535
  OuterSyntax.improper_command "normal_form" "normalize term by evaluation" K.diag
haftmann@28227
   536
    (opt_modes -- P.term >> (Toplevel.keep o norm_print_term_cmd));
haftmann@24155
   537
haftmann@24155
   538
end;
haftmann@24155
   539
haftmann@24155
   540
end;
haftmann@28337
   541