(* ID: $Id$
Author: Tobias Nipkow, Florian Haftmann, TU Muenchen
Toplevel theory interface for "normalization by evaluation"
*)
signature NBE =
sig
val norm_by_eval_i: term -> theory -> term * theory;
val lookup: string -> NBE_Eval.Univ;
val update: string * NBE_Eval.Univ -> unit;
end;
structure NBE: NBE =
struct
structure NBE_Data = TheoryDataFun
(struct
val name = "Pure/NBE";
type T = NBE_Eval.Univ Symtab.table;
val empty = Symtab.empty;
val copy = I;
val extend = I;
fun merge _ = Symtab.merge (K true);
fun print _ _ = ();
end);
val _ = Context.add_setup NBE_Data.init;
val tab : NBE_Eval.Univ Symtab.table ref = ref Symtab.empty;
fun lookup s = (the o Symtab.lookup (!tab)) s;
fun update sx = (tab := Symtab.update sx (!tab));
fun defined s = Symtab.defined (!tab) s;
fun use_show s = (writeln ("\n---generated code:\n"^ s);
use_text(writeln o enclose "\n---compiler echo:\n" "\n---\n",
writeln o enclose "\n--- compiler echo (with error!):\n"
"\n---\n")
true s);
fun norm_by_eval_i t thy =
let
val nbe_tab = NBE_Data.get thy;
val modl_old = CodegenThingol.partof (Symtab.keys nbe_tab)
(CodegenPackage.get_root_module thy);
val (t', thy') = CodegenPackage.codegen_term t thy;
val modl_new = CodegenPackage.get_root_module thy';
val diff = CodegenThingol.diff_module (modl_new, modl_old);
val _ = writeln ("new definitions: " ^ (commas o map fst) diff);
val _ = (tab := nbe_tab;
Library.seq (use_show o NBE_Codegen.generate defined) diff);
val thy'' = NBE_Data.put (!tab) thy';
val nt' = NBE_Eval.nbe (!tab) t';
val t' = NBE_Codegen.nterm_to_term thy'' nt';
val _ = print nt';
val _ = (Pretty.writeln o Sign.pretty_term thy'') t';
in
(t', thy'')
end;
fun norm_by_eval raw_t thy = norm_by_eval_i (Sign.read_term thy raw_t) thy;
structure P = OuterParse and K = OuterKeyword;
val nbeP =
OuterSyntax.command "norm_by_eval" "normalization by evaluation" K.thy_decl
(P.term >> (fn t => Toplevel.theory (snd o norm_by_eval t)));
val _ = OuterSyntax.add_parsers [nbeP];
end;