represent constants with explicit typargs to avoid false positives for equality approximations like ‹card UNIV === card UNIV›
(* Title: Tools/nbe.ML
Authors: Klaus Aehlig, LMU Muenchen; Tobias Nipkow, Florian Haftmann, TU Muenchen
Normalization by evaluation, based on generic code generator.
*)
signature NBE =
sig
val dynamic_conv: Proof.context -> conv
val dynamic_value: Proof.context -> term -> term
val static_conv: { ctxt: Proof.context, consts: string list }
-> Proof.context -> conv
val static_value: { ctxt: Proof.context, consts: string list }
-> Proof.context -> term -> term
datatype Type =
Type of string * Type list
| TParam of string
datatype Univ =
Const of (int * Type list) * Univ list (*named (uninterpreted) constants*)
| DFree of string * int (*free (uninterpreted) dictionary parameters*)
| BVar of int * Univ list (*bound variables, named*)
| Abs of (int * (Univ list -> Univ)) * Univ list
val apps: Univ -> Univ list -> Univ (*explicit applications*)
val abss: int -> (Univ list -> Univ) -> Univ
(*abstractions as closures*)
val same: Univ * Univ -> bool
val put_result: (unit -> (Type list -> Univ) list -> (Type list -> Univ) list)
-> Proof.context -> Proof.context
val trace: bool Config.T
val add_const_alias: thm -> theory -> theory
end;
structure Nbe: NBE =
struct
(* generic non-sense *)
val trace = Attrib.setup_config_bool \<^binding>\<open>nbe_trace\<close> (K false);
fun traced ctxt f x = if Config.get ctxt trace then (tracing (f x); x) else x;
(** certificates and oracle for "trivial type classes" **)
structure Triv_Class_Data = Theory_Data
(
type T = (class * thm) list;
val empty = [];
fun merge data : T = AList.merge (op =) (K true) data;
);
fun add_const_alias thm thy =
let
val (ofclass, eqn) = case try Logic.dest_equals (Thm.prop_of thm)
of SOME ofclass_eq => ofclass_eq
| _ => error ("Bad certificate: " ^ Thm.string_of_thm_global thy thm);
val (T, class) = case try Logic.dest_of_class ofclass
of SOME T_class => T_class
| _ => error ("Bad certificate: " ^ Thm.string_of_thm_global thy thm);
val tvar = case try Term.dest_TVar T
of SOME (tvar as (_, sort)) => if null (filter (can (Axclass.get_info thy)) sort)
then tvar
else error ("Bad sort: " ^ Thm.string_of_thm_global thy thm)
| _ => error ("Bad type: " ^ Thm.string_of_thm_global thy thm);
val _ = if Term.add_tvars eqn [] = [tvar] then ()
else error ("Inconsistent type: " ^ Thm.string_of_thm_global thy thm);
val lhs_rhs = case try Logic.dest_equals eqn
of SOME lhs_rhs => lhs_rhs
| _ => error ("Not an equation: " ^ Syntax.string_of_term_global thy eqn);
val c_c' = case try (apply2 (Axclass.unoverload_const thy o dest_Const)) lhs_rhs
of SOME c_c' => c_c'
| _ => error ("Not an equation with two constants: "
^ Syntax.string_of_term_global thy eqn);
val _ = if the_list (Axclass.class_of_param thy (snd c_c')) = [class] then ()
else error ("Inconsistent class: " ^ Thm.string_of_thm_global thy thm);
in Triv_Class_Data.map (AList.update (op =) (class, Thm.trim_context thm)) thy end;
local
val get_triv_classes = map fst o Triv_Class_Data.get;
val (_, triv_of_class) =
Theory.setup_result (Thm.add_oracle (\<^binding>\<open>triv_of_class\<close>,
fn (thy, T, class) => Thm.global_cterm_of thy (Logic.mk_of_class (T, class))));
in
fun lift_triv_classes_conv orig_ctxt conv ct =
let
val thy = Proof_Context.theory_of orig_ctxt;
val ctxt = Proof_Context.init_global thy;
(*FIXME quasi-global context*)
val algebra = Sign.classes_of thy;
val triv_classes = get_triv_classes thy;
fun additional_classes sort = filter_out (fn class => Sorts.sort_le algebra (sort, [class])) triv_classes;
fun mk_entry (v, sort) =
let
val T = TFree (v, sort);
val cT = Thm.ctyp_of ctxt T;
val triv_sort = additional_classes sort;
in
(v, (Sorts.inter_sort algebra (sort, triv_sort),
(cT, AList.make (fn class => Thm.of_class (cT, class)) sort
@ AList.make (fn class => triv_of_class (thy, T, class)) triv_sort)))
end;
val vs_tab = map mk_entry (Term.add_tfrees (Thm.term_of ct) []);
fun instantiate thm =
let
val tvars =
Term.add_tvars (#1 (Logic.dest_equals (Logic.strip_imp_concl (Thm.prop_of thm)))) [];
val instT = map2 (fn v => fn (_, (_, (cT, _))) => (v, cT)) tvars vs_tab;
in Thm.instantiate (TVars.make instT, Vars.empty) thm end;
fun of_class (TFree (v, _), class) =
the (AList.lookup (op =) ((snd o snd o the o AList.lookup (op =) vs_tab) v) class)
| of_class (T, _) = error ("Bad type " ^ Syntax.string_of_typ ctxt T);
fun strip_of_class thm =
let
val prems_of_class = Thm.prop_of thm
|> Logic.strip_imp_prems
|> map (Logic.dest_of_class #> of_class);
in fold Thm.elim_implies prems_of_class thm end;
in
ct
|> Thm.term_of
|> (map_types o map_type_tfree)
(fn (v, _) => TFree (v, (fst o the o AList.lookup (op =) vs_tab) v))
|> Thm.cterm_of ctxt
|> conv ctxt
|> Thm.strip_shyps
|> Thm.varifyT_global
|> Thm.unconstrainT
|> instantiate
|> strip_of_class
end;
fun lift_triv_classes_rew ctxt rew t =
let
val thy = Proof_Context.theory_of ctxt;
val algebra = Sign.classes_of thy;
val triv_classes = get_triv_classes thy;
val vs = Term.add_tfrees t [];
in
t
|> (map_types o map_type_tfree)
(fn (v, sort) => TFree (v, Sorts.inter_sort algebra (sort, triv_classes)))
|> rew
|> (map_types o map_type_tfree)
(fn (v, sort) => TFree (v, the_default sort (AList.lookup (op =) vs v)))
end;
end;
(** the semantic universe **)
(*
Functions are given by their semantic function value. To avoid
trouble with the ML-type system, these functions have the most
generic type, that is "Univ list -> Univ". The calling convention is
that the arguments come as a list, the last argument first. In
other words, a function call that usually would look like
f x_1 x_2 ... x_n or f(x_1,x_2, ..., x_n)
would be in our convention called as
f [x_n,..,x_2,x_1]
Moreover, to handle functions that are still waiting for some
arguments we have additionally a list of arguments collected to far
and the number of arguments we're still waiting for.
*)
datatype Type =
Type of string * Type list
| TParam of string
datatype Univ =
Const of (int * Type list) * Univ list (*named (uninterpreted) constants*)
| DFree of string * int (*free (uninterpreted) dictionary parameters*)
| BVar of int * Univ list (*bound variables, named*)
| Abs of (int * (Univ list -> Univ)) * Univ list
(*abstractions as closures*)
(* constructor functions *)
fun abss n f = Abs ((n, f), []);
fun apps (Abs ((n, f), xs)) ys = let val k = n - length ys in
case int_ord (k, 0)
of EQUAL => f (ys @ xs)
| LESS => let val (zs, ws) = chop (~ k) ys in apps (f (ws @ xs)) zs end
| GREATER => Abs ((k, f), ys @ xs) (*note: reverse convention also for apps!*)
end
| apps (Const (name, xs)) ys = Const (name, ys @ xs)
| apps (BVar (n, xs)) ys = BVar (n, ys @ xs);
fun same_type (Type (tyco1, types1), Type (tyco2, types2)) =
(tyco1 = tyco2) andalso eq_list same_type (types1, types2)
| same_type (TParam v1, TParam v2) = (v1 = v2)
| same_type _ = false;
fun same (Const ((k1, ts1), xs1), Const ((k2, ts2), xs2)) =
(k1 = k2) andalso eq_list same_type (ts1, ts2) andalso eq_list same (xs1, xs2)
| same (DFree (n1, i1), DFree (n2, i2)) = (n1 = n2) andalso (i1 = i2)
| same (BVar (i1, xs1), BVar (i2, xs2)) = (i1 = i2) andalso eq_list same (xs1, xs2)
| same _ = false;
(** assembling and compiling ML code from terms **)
(* abstract ML syntax *)
infix 9 `$` `$$`;
fun e1 `$` e2 = "(" ^ e1 ^ " " ^ e2 ^ ")";
fun e `$$` [] = e
| e `$$` es = "(" ^ e ^ " " ^ implode_space es ^ ")";
fun ml_abs v e = "(fn " ^ v ^ " => " ^ e ^ ")";
fun ml_cases t cs =
"(case " ^ t ^ " of " ^ space_implode " | " (map (fn (p, t) => p ^ " => " ^ t) cs) ^ ")";
fun ml_Let d e = "let\n" ^ d ^ " in " ^ e ^ " end";
fun ml_as v t = "(" ^ v ^ " as " ^ t ^ ")";
fun ml_and [] = "true"
| ml_and [x] = x
| ml_and xs = "(" ^ space_implode " andalso " xs ^ ")";
fun ml_if b x y = "(if " ^ b ^ " then " ^ x ^ " else " ^ y ^ ")";
fun ml_list es = "[" ^ commas es ^ "]";
fun ml_fundefs ([(name, [([], e)])]) =
"val " ^ name ^ " = " ^ e ^ "\n"
| ml_fundefs (eqs :: eqss) =
let
fun fundef (name, eqs) =
let
fun eqn (es, e) = name ^ " " ^ implode_space es ^ " = " ^ e
in space_implode "\n | " (map eqn eqs) end;
in
(prefix "fun " o fundef) eqs :: map (prefix "and " o fundef) eqss
|> cat_lines
|> suffix "\n"
end;
(* nbe specific syntax and sandbox communication *)
structure Univs = Proof_Data
(
type T = unit -> (Type list -> Univ) list -> (Type list -> Univ) list;
val empty: T = fn () => raise Fail "Univs";
fun init _ = empty;
);
val get_result = Univs.get;
val put_result = Univs.put;
local
val prefix = "Nbe.";
val name_put = prefix ^ "put_result";
val name_const = prefix ^ "Const";
val name_type = prefix ^ "Type";
val name_abss = prefix ^ "abss";
val name_apps = prefix ^ "apps";
val name_same = prefix ^ "same";
in
val univs_cookie = (get_result, put_result, name_put);
fun nbe_type n ts = name_type `$` ("(" ^ quote n ^ ", " ^ ml_list ts ^ ")")
fun nbe_tparam v = "t_" ^ v;
fun nbe_dict v n = "d_" ^ v ^ "_" ^ string_of_int n;
fun nbe_bound v = "v_" ^ v;
fun nbe_bound_optional NONE = "_"
| nbe_bound_optional (SOME v) = nbe_bound v;
fun nbe_default v = "w_" ^ v;
(*note: these three are the "turning spots" where proper argument order is established!*)
fun nbe_apps t [] = t
| nbe_apps t ts = name_apps `$$` [t, ml_list (rev ts)];
fun nbe_apps_local c tys ts = c `$` ml_list tys `$` ml_list (rev ts);
fun nbe_apps_constr c tys ts = name_const `$` ("((" ^ c ^ ", " ^ ml_list tys ^ "), " ^ ml_list (rev ts) ^ ")");
fun nbe_apps_constmatch c ts = name_const `$` ("((" ^ c ^ ", _), " ^ ml_list (rev ts) ^ ")");
fun nbe_abss 0 f = f `$` ml_list []
| nbe_abss n f = name_abss `$$` [string_of_int n, f];
fun nbe_same (v1, v2) = "(" ^ name_same ^ " (" ^ nbe_bound v1 ^ ", " ^ nbe_bound v2 ^ "))";
end;
open Basic_Code_Symbol;
open Basic_Code_Thingol;
(* code generation *)
fun subst_nonlin_vars args =
let
val vs = (fold o Code_Thingol.fold_varnames)
(fn v => AList.map_default (op =) (v, 0) (Integer.add 1)) args [];
val names = Name.make_context (map fst vs);
val (vs_renames, _) = fold_map (fn (v, k) => if k > 1
then Name.invent' v (k - 1) #>> (fn vs => (v, vs))
else pair (v, [])) vs names;
val samepairs = maps (fn (v, vs) => map (pair v) vs) vs_renames;
fun subst_vars (t as IConst _) samepairs = (t, samepairs)
| subst_vars (t as IVar NONE) samepairs = (t, samepairs)
| subst_vars (t as IVar (SOME v)) samepairs = (case AList.lookup (op =) samepairs v
of SOME v' => (IVar (SOME v'), AList.delete (op =) v samepairs)
| NONE => (t, samepairs))
| subst_vars (t1 `$ t2) samepairs = samepairs
|> subst_vars t1
||>> subst_vars t2
|>> (op `$)
| subst_vars (ICase { primitive = t, ... }) samepairs = subst_vars t samepairs;
val (args', _) = fold_map subst_vars args samepairs;
in (samepairs, args') end;
fun preprocess_eqns (sym, (vs, eqns)) =
let
val s_tparams = map (fn (v, _) => nbe_tparam v) vs;
val dict_params = maps (fn (v, sort) => map_index (nbe_dict v o fst) sort) vs;
val num_args = length dict_params + ((length o fst o hd) eqns);
val default_params = map nbe_default (Name.invent_global "a" (num_args - length dict_params));
in (sym, (num_args, (s_tparams, dict_params, (map o apfst) subst_nonlin_vars eqns, default_params))) end;
fun assemble_type (tyco `%% tys) = nbe_type tyco (map assemble_type tys)
| assemble_type (ITyVar v) = nbe_tparam v
fun assemble_preprocessed_eqnss ctxt idx_of_const deps eqnss =
let
fun fun_ident 0 (Code_Symbol.Constant "") = "nbe_value"
| fun_ident i sym = "c_" ^ string_of_int (idx_of_const sym)
^ "_" ^ Code_Symbol.default_base sym ^ "_" ^ string_of_int i;
fun constr_fun_ident c =
if Config.get ctxt trace
then string_of_int (idx_of_const c) ^ " (*" ^ Code_Symbol.default_base c ^ "*)"
else string_of_int (idx_of_const c);
fun apply_local i sym = nbe_apps_local (fun_ident i sym);
fun apply_constr sym = nbe_apps_constr (constr_fun_ident sym);
fun apply_constmatch sym = nbe_apps_constmatch (constr_fun_ident sym);
fun assemble_constapp sym tys dicts ts =
let
val s_tys = map (assemble_type) tys;
val ts' = (maps o map) assemble_dict (map2 (fn ty => map (fn dict => (ty, dict))) tys dicts) @ ts;
in case AList.lookup (op =) eqnss sym
of SOME (num_args, _) => if num_args <= length ts'
then let val (ts1, ts2) = chop num_args ts'
in nbe_apps (apply_local 0 sym s_tys ts1) ts2
end else nbe_apps (nbe_abss num_args (fun_ident 0 sym `$` ml_list s_tys)) ts'
| NONE => if member (op =) deps sym
then nbe_apps (fun_ident 0 sym `$` ml_list s_tys) ts'
else apply_constr sym s_tys ts'
end
and assemble_classrels classrels =
fold_rev (fn classrel => assemble_constapp (Class_Relation classrel) [] [] o single) classrels
and assemble_dict (ty, Dict (classrels, x)) =
assemble_classrels classrels (assemble_plain_dict ty x)
and assemble_plain_dict (_ `%% tys) (Dict_Const (inst, dicts)) =
assemble_constapp (Class_Instance inst) tys (map snd dicts) []
| assemble_plain_dict _ (Dict_Var { var, index, ... }) =
nbe_dict var index
fun assemble_constmatch sym _ dicts ts =
apply_constmatch sym ((maps o map) (K "_") dicts @ ts);
fun assemble_iterm constapp =
let
fun of_iterm match_continuation t =
let
val (t', ts) = Code_Thingol.unfold_app t
in of_iapp match_continuation t' (fold_rev (cons o of_iterm NONE) ts []) end
and of_iapp match_continuation (IConst { sym, typargs = tys, dicts, ... }) ts = constapp sym tys dicts ts
| of_iapp match_continuation (IVar v) ts = nbe_apps (nbe_bound_optional v) ts
| of_iapp match_continuation ((v, _) `|=> (t, _)) ts =
nbe_apps (nbe_abss 1 (ml_abs (ml_list [nbe_bound_optional v]) (of_iterm NONE t))) ts
| of_iapp match_continuation (ICase { term = t, clauses = clauses, primitive = t0, ... }) ts =
nbe_apps (ml_cases (of_iterm NONE t)
(map (fn (p, t) => (assemble_iterm assemble_constmatch NONE p, of_iterm match_continuation t)) clauses
@ [("_", case match_continuation of SOME s => s | NONE => of_iterm NONE t0)])) ts
in of_iterm end;
val assemble_args = map (assemble_iterm assemble_constmatch NONE);
val assemble_rhs = assemble_iterm assemble_constapp;
fun assemble_eqn sym s_tparams dict_params default_params (i, ((samepairs, args), rhs)) =
let
val default_rhs = apply_local (i + 1) sym s_tparams (dict_params @ default_params);
val s_args = assemble_args args;
val s_rhs = if null samepairs then assemble_rhs (SOME default_rhs) rhs
else ml_if (ml_and (map nbe_same samepairs))
(assemble_rhs (SOME default_rhs) rhs) default_rhs;
val eqns = [([ml_list s_tparams, ml_list (rev (dict_params @ map2 ml_as default_params s_args))], s_rhs),
([ml_list s_tparams, ml_list (rev (dict_params @ default_params))], default_rhs)]
in (fun_ident i sym, eqns) end;
fun assemble_default_eqn sym s_tparams dict_params default_params i =
(fun_ident i sym,
[([ml_list s_tparams, ml_list (rev (dict_params @ default_params))], apply_constr sym s_tparams (dict_params @ default_params))])
fun assemble_value_eqn sym s_tparams dict_params (([], args), rhs) =
(fun_ident 0 sym,
[([ml_list s_tparams, ml_list (rev (dict_params @ assemble_args args))], assemble_rhs NONE rhs)]);
fun assemble_eqns (sym, (num_args, (s_tparams, dict_params, eqns, default_params))) =
(if Code_Symbol.is_value sym then [assemble_value_eqn sym s_tparams dict_params (the_single eqns)]
else map_index (assemble_eqn sym s_tparams dict_params default_params) eqns
@ [assemble_default_eqn sym s_tparams dict_params default_params (length eqns)],
ml_abs (ml_list s_tparams) (nbe_abss num_args (fun_ident 0 sym `$` ml_list s_tparams)));
val (fun_vars, fun_vals) = map_split assemble_eqns eqnss;
val deps_vars = ml_list (map (fun_ident 0) deps);
in ml_abs deps_vars (ml_Let (ml_fundefs (flat fun_vars)) (ml_list fun_vals)) end;
fun assemble_eqnss ctxt idx_of_const deps eqnss =
assemble_preprocessed_eqnss ctxt idx_of_const deps (map preprocess_eqns eqnss);
(* compilation of equations *)
fun compile_eqnss ctxt nbe_program raw_deps [] = []
| compile_eqnss ctxt nbe_program raw_deps eqnss =
let
val (deps, deps_vals) = split_list (map_filter
(fn dep => Option.map (fn univ => (dep, univ)) (fst ((Code_Symbol.Graph.get_node nbe_program dep)))) raw_deps);
val idx_of_const = raw_deps
|> map (fn dep => (dep, snd (Code_Symbol.Graph.get_node nbe_program dep)))
|> AList.lookup (op =)
|> (fn f => the o f);
val s = assemble_eqnss ctxt idx_of_const deps eqnss;
val syms = map fst eqnss;
in
s
|> traced ctxt (fn s => "\n--- code to be evaluated:\n" ^ s)
|> pair ""
|> Code_Runtime.value ctxt univs_cookie
|> (fn f => f deps_vals)
|> (fn poly_univs => syms ~~ poly_univs)
end;
(* extraction of equations from statements *)
fun dummy_const sym tys dicts =
IConst { sym = sym, typargs = tys, dicts = dicts,
dom = [], annotation = NONE, range = ITyVar "" };
fun eqns_of_stmt (_, Code_Thingol.NoStmt) =
[]
| eqns_of_stmt (_, Code_Thingol.Fun ((_, []), _)) =
[]
| eqns_of_stmt (sym_const, Code_Thingol.Fun (((vs, _), eqns), _)) =
[(sym_const, (vs, map fst eqns))]
| eqns_of_stmt (_, Code_Thingol.Datatypecons _) =
[]
| eqns_of_stmt (_, Code_Thingol.Datatype _) =
[]
| eqns_of_stmt (sym_class, Code_Thingol.Class (v, (classrels, classparams))) =
let
val syms = map (rpair [] o Class_Relation) classrels @ map (rpair [(v, [])] o Constant o fst) classparams;
val params = Name.invent_global "d" (length syms);
fun mk (k, (sym, vs)) =
(sym, (vs,
[([dummy_const sym_class [] [] `$$ map (IVar o SOME) params],
IVar (SOME (nth params k)))]));
in map_index mk syms end
| eqns_of_stmt (_, Code_Thingol.Classrel _) =
[]
| eqns_of_stmt (_, Code_Thingol.Classparam _) =
[]
| eqns_of_stmt (sym_inst, Code_Thingol.Classinst { class, tyco, vs, superinsts, inst_params, ... }) =
[(sym_inst, (vs, [([], dummy_const (Type_Class class) [] [] `$$
map (fn (class, dicts) =>
dummy_const (Class_Instance (tyco, class)) (map (ITyVar o fst) vs) (map snd dicts)) superinsts
@ map (IConst o fst o snd o fst) inst_params)]))];
(* compilation of whole programs *)
fun ensure_const_idx name (nbe_program, (maxidx, const_tab)) =
if can (Code_Symbol.Graph.get_node nbe_program) name
then (nbe_program, (maxidx, const_tab))
else (Code_Symbol.Graph.new_node (name, (NONE, maxidx)) nbe_program,
(maxidx + 1, Inttab.update_new (maxidx, name) const_tab));
fun compile_stmts ctxt stmts_deps =
let
val names = map (fst o fst) stmts_deps;
val names_deps = map (fn ((name, _), deps) => (name, deps)) stmts_deps;
val eqnss = maps (eqns_of_stmt o fst) stmts_deps;
val refl_deps = names_deps
|> maps snd
|> distinct (op =)
|> fold (insert (op =)) names;
fun compile nbe_program = eqnss
|> compile_eqnss ctxt nbe_program refl_deps
|> rpair nbe_program;
in
fold ensure_const_idx refl_deps
#> apfst (fold (fn (name, deps) => fold (curry Code_Symbol.Graph.add_edge name) deps) names_deps
#> compile
#-> fold (fn (sym, univ) => (Code_Symbol.Graph.map_node sym o apfst) (K (SOME univ))))
end;
fun compile_program { ctxt, program } =
let
fun add_stmts names (nbe_program, (maxidx, const_tab)) =
if exists ((can o Code_Symbol.Graph.get_node) nbe_program) names
then (nbe_program, (maxidx, const_tab))
else (nbe_program, (maxidx, const_tab))
|> compile_stmts ctxt (map (fn sym => ((sym, Code_Symbol.Graph.get_node program sym),
Code_Symbol.Graph.immediate_succs program sym)) names);
in
fold_rev add_stmts (Code_Symbol.Graph.strong_conn program)
end;
(** normalization **)
(* compilation and reconstruction of terms *)
fun ad_hoc_eqn_of_term ((vs, _) : typscheme, t) =
(Code_Symbol.value, (vs, [([], t)]));
fun compile_term { ctxt, nbe_program, deps, tfrees, vs_ty_t = vs_ty_t as ((vs, _), _) } =
let
val tparams = map (fn (v, _) => TParam v) tfrees;
val dict_frees = maps (fn (v, sort) => map_index (curry DFree v o fst) sort) vs;
in
ad_hoc_eqn_of_term vs_ty_t
|> singleton (compile_eqnss ctxt nbe_program deps)
|> snd
|> (fn f => apps (f tparams) (rev dict_frees))
end;
fun reconstruct_term ctxt const_tab tfrees t =
let
fun take_until f [] = []
| take_until f (x :: xs) = if f x then [] else x :: take_until f xs;
fun is_dict (Const ((idx, _), _)) =
(case Inttab.lookup const_tab idx of
SOME (Constant _) => false
| _ => true)
| is_dict (DFree _) = true
| is_dict _ = false;
fun const_of_idx idx =
case Inttab.lookup const_tab idx of SOME (Constant const) => const;
fun reconstruct_type (Type (tyco, tys)) = Term.Type (tyco, map reconstruct_type tys)
| reconstruct_type (TParam v) = TFree (v, the (AList.lookup (op =) tfrees v));
fun of_apps bounds (t, ts) =
list_comb (t, rev (map (of_univ bounds) ts))
and of_univ bounds (Const ((idx, tys), ts)) =
let
val const = const_of_idx idx;
val ts' = take_until is_dict ts;
val T = Consts.instance (Proof_Context.consts_of ctxt) (const, map reconstruct_type tys);
in of_apps bounds (Term.Const (const, T), ts') end
| of_univ bounds (BVar (n, ts)) =
of_apps bounds (Bound (bounds - n - 1), ts)
| of_univ bounds (t as Abs _) =
Term.Abs ("u", dummyT, of_univ (bounds + 1) (apps t [BVar (bounds, [])]))
in of_univ 0 t end;
fun compile_and_reconstruct_term { ctxt, nbe_program, const_tab, deps, tfrees, vs_ty_t } =
compile_term { ctxt = ctxt, nbe_program = nbe_program, deps = deps, tfrees = tfrees, vs_ty_t = vs_ty_t }
|> reconstruct_term ctxt const_tab tfrees;
fun retype_term ctxt t T =
let
val ctxt' =
ctxt
|> Variable.declare_typ T
|> Config.put Type_Infer.object_logic false
|> Config.put Type_Infer_Context.const_sorts false
in
singleton (Variable.export_terms ctxt' ctxt') (Syntax.check_term ctxt' (Type.constraint T t))
end;
fun normalize_term (nbe_program, const_tab) raw_ctxt t_original vs_ty_t deps =
let
val T = fastype_of t_original;
val tfrees = Term.add_tfrees t_original [];
val ctxt = Syntax.init_pretty_global (Proof_Context.theory_of raw_ctxt);
val string_of_term =
Syntax.string_of_term
(ctxt
|> Config.put show_types true
|> Config.put show_sorts true);
fun retype t' = retype_term ctxt t' T;
fun check_tvars t' =
if null (Term.add_tvars t' []) then t'
else error ("Illegal schematic type variables in normalized term: " ^ string_of_term t');
in
Code_Preproc.timed "computing NBE expression" #ctxt compile_and_reconstruct_term
{ ctxt = ctxt, nbe_program = nbe_program, const_tab = const_tab, deps = deps,
tfrees = tfrees, vs_ty_t = vs_ty_t }
|> traced ctxt (fn t => "Normalized:\n" ^ string_of_term t)
|> retype
|> traced ctxt (fn t => "Types inferred:\n" ^ string_of_term t)
|> check_tvars
|> traced ctxt (fn _ => "---\n")
end;
(* function store *)
structure Nbe_Functions = Code_Data
(
type T = ((Type list -> Univ) option * int) Code_Symbol.Graph.T * (int * Code_Symbol.T Inttab.table);
val empty = (Code_Symbol.Graph.empty, (0, Inttab.empty));
);
fun compile ignore_cache ctxt program =
let
val (nbe_program, (_, const_tab)) =
Nbe_Functions.change (if ignore_cache then NONE else SOME (Proof_Context.theory_of ctxt))
(Code_Preproc.timed "compiling NBE program" #ctxt
compile_program { ctxt = ctxt, program = program });
in (nbe_program, const_tab) end;
(* evaluation oracle *)
fun mk_equals ctxt lhs raw_rhs =
let
val ty = Thm.typ_of_cterm lhs;
val eq = Thm.cterm_of ctxt \<^Const>\<open>Pure.eq ty\<close>;
val rhs = Thm.cterm_of ctxt raw_rhs;
in Thm.mk_binop eq lhs rhs end;
val (_, raw_oracle) =
Theory.setup_result (Thm.add_oracle (\<^binding>\<open>normalization_by_evaluation\<close>,
fn (nbe_program_const_tab, ctxt, vs_ty_t, deps, ct) =>
mk_equals ctxt ct (normalize_term nbe_program_const_tab ctxt (Thm.term_of ct) vs_ty_t deps)));
fun oracle nbe_program_const_tab ctxt vs_ty_t deps ct =
raw_oracle (nbe_program_const_tab, ctxt, vs_ty_t, deps, ct);
fun dynamic_conv ctxt = lift_triv_classes_conv ctxt
(fn ctxt' => Code_Thingol.dynamic_conv ctxt' (fn program =>
oracle (compile false ctxt program) ctxt'));
fun dynamic_value ctxt = lift_triv_classes_rew ctxt
(Code_Thingol.dynamic_value ctxt I (fn program =>
normalize_term (compile false ctxt program) ctxt));
fun static_conv (ctxt_consts as { ctxt, ... }) =
let
val conv = Code_Thingol.static_conv_thingol ctxt_consts
(fn { program, deps = _ } => oracle (compile true ctxt program));
in fn ctxt' => lift_triv_classes_conv ctxt' conv end;
fun static_value { ctxt, consts } =
let
val comp = Code_Thingol.static_value { ctxt = ctxt, lift_postproc = I, consts = consts }
(fn { program, deps = _ } => normalize_term (compile false ctxt program));
in fn ctxt' => lift_triv_classes_rew ctxt' (comp ctxt') end;
end;