(*  Title:      Pure/ML/ml_context.ML

    ID:         $Id$

    Author:     Makarius

ML context and antiquotations.

*)

signature BASIC_ML_CONTEXT =

sig

  val the_context: unit -> theory

  val thm: xstring -> thm

  val thms: xstring -> thm list

end

signature ML_CONTEXT =

sig

  include BASIC_ML_CONTEXT

  val get_context: unit -> Context.generic option

  val set_context: Context.generic option -> unit

  val setmp: Context.generic option -> ('a -> 'b) -> 'a -> 'b

  val the_generic_context: unit -> Context.generic

  val the_local_context: unit -> Proof.context

  val pass: Context.generic option -> ('a -> 'b) -> 'a -> 'b * Context.generic option

  val pass_context: Context.generic -> ('a -> 'b) -> 'a -> 'b * Context.generic

  val save: ('a -> 'b) -> 'a -> 'b

  val >> : (theory -> theory) -> unit

  val add_keywords: string list -> unit

  val inline_antiq: string ->

    (Context.generic * Args.T list -> string * (Context.generic * Args.T list)) -> unit

  val value_antiq: string ->

    (Context.generic * Args.T list -> (string * string) * (Context.generic * Args.T list)) -> unit

  val proj_value_antiq: string -> (Context.generic * Args.T list ->

      (string * string * string) * (Context.generic * Args.T list)) -> unit

  val eval_antiquotes_fn: (string -> string * string) ref  (* FIXME tmp *)

  val trace: bool ref

  val use_mltext: string -> bool -> Context.generic option -> unit

  val use_mltext_update: string -> bool -> Context.generic -> Context.generic

  val use_let: string -> string -> string -> Context.generic -> Context.generic

  val use: Path.T -> unit

  val evaluate: (string -> unit) * (string -> 'b) -> bool ->

    string * (unit -> 'a) option ref -> string -> 'a

end

structure ML_Context: ML_CONTEXT =

struct

(** Implicit ML context **)

local

  val current_context = ref (NONE: Context.generic option);

in

  fun get_context () = ! current_context;

  fun set_context opt_context = current_context := opt_context;

  fun setmp opt_context f x = Library.setmp current_context opt_context f x;

end;

fun the_generic_context () =

  (case get_context () of

    SOME context => context

  | _ => error "Unknown context");

val the_local_context = Context.proof_of o the_generic_context;

val the_context = Context.theory_of o the_generic_context;

fun pass opt_context f x =

  setmp opt_context (fn x => let val y = f x in (y, get_context ()) end) x;

fun pass_context context f x =

  (case pass (SOME context) f x of

    (y, SOME context') => (y, context')

  | (_, NONE) => error "Lost context in ML");

fun save f x = NAMED_CRITICAL "ML" (fn () => setmp (get_context ()) f x);

fun change_theory f = NAMED_CRITICAL "ML" (fn () =>

  set_context (SOME (Context.map_theory f (the_generic_context ()))));

(** ML antiquotations **)

(* maintain keywords *)

val global_lexicon = ref Scan.empty_lexicon;

fun add_keywords keywords = CRITICAL (fn () =>

  change global_lexicon (Scan.extend_lexicon (map Symbol.explode keywords)));

(* maintain commands *)

datatype antiq = Inline of string | ProjValue of string * string * string;

val global_parsers = ref (Symtab.empty:

  (Context.generic * Args.T list -> antiq * (Context.generic * Args.T list)) Symtab.table);

local

fun add_item kind name scan = CRITICAL (fn () =>

  change global_parsers (fn tab =>

   (if not (Symtab.defined tab name) then ()

    else warning ("Redefined ML antiquotation: " ^ quote name);

    Symtab.update (name, scan >> kind) tab)));

in

val inline_antiq = add_item Inline;

val proj_value_antiq = add_item ProjValue;

fun value_antiq name scan = proj_value_antiq name (scan >> (fn (a, s) => (a, s, "")));

end;

(* command syntax *)

fun syntax scan src =

  #1 (Args.context_syntax "ML antiquotation" scan src (the_local_context ()));

fun command src =

  let val ((name, _), pos) = Args.dest_src src in

    (case Symtab.lookup (! global_parsers) name of

      NONE => error ("Unknown ML antiquotation command: " ^ quote name ^ Position.str_of pos)

    | SOME scan => syntax scan src)

  end;

(* outer syntax *)

structure T = OuterLex;

structure P = OuterParse;

val antiq =

  P.!!! (P.position P.xname -- P.arguments --| Scan.ahead P.eof)

  >> (fn ((x, pos), y) => Args.src ((x, y), pos));

(* input/output wrappers *)

local

val isabelle_struct = enclose "structure Isabelle =\nstruct\n" "end;";

val isabelle_struct0 = isabelle_struct "";

fun eval_antiquotes txt =

  let

    val ants = Antiquote.scan_antiquotes (txt, Position.line 1);

    fun expand (Antiquote.Text s) names = (("", Symbol.escape s), names)

      | expand (Antiquote.Antiq x) names =

          (case command (Antiquote.scan_arguments (! global_lexicon) antiq x) of

            Inline s => (("", s), names)

          | ProjValue (a, s, f) =>

              let

                val a' = if ML_Syntax.is_identifier a then a else "val";

                val ([b], names') = Name.variants [a'] names;

                val binding = "val " ^ b ^ " = " ^ s ^ ";\n";

                val value =

                  if f = "" then "Isabelle." ^ b

                  else "(" ^ f ^ " Isabelle." ^ b ^ ")";

              in ((binding, value), names') end);

    val (decls, body) =

      NAMED_CRITICAL "ML" (fn () => fold_map expand ants ML_Syntax.reserved)

      |> #1 |> split_list |> pairself implode;

  in (isabelle_struct decls, body) end;

in

val eval_antiquotes_fn = ref eval_antiquotes;

val trace = ref false;

fun eval_wrapper name pr verbose txt =

  let

    val (txt1, txt2) = ! eval_antiquotes_fn txt;  (* FIXME tmp hook *)

    val _ = if ! trace then tracing (cat_lines [txt1, txt2]) else ();

    fun eval nm = use_text nm pr;

  in

    NAMED_CRITICAL "ML" (fn () =>

      (eval "" false txt1; eval name verbose txt2; eval "" false isabelle_struct0))

  end;

fun ML_wrapper pr = eval_wrapper "ML" pr;

end;

(* ML evaluation *)

fun use_mltext txt verbose opt_context =

  setmp opt_context (fn () => ML_wrapper Output.ml_output verbose txt) ();

fun use_mltext_update txt verbose context =

  #2 (pass_context context (fn () => ML_wrapper Output.ml_output verbose txt) ());

fun use_context txt = use_mltext_update

  ("ML_Context.set_context (SOME ((" ^ txt ^ ") (ML_Context.the_generic_context ())));") false;

fun use_let bind body txt =

  use_context ("let " ^ bind ^ " = " ^ txt ^ " in\n" ^ body ^ " end");

fun use path = eval_wrapper (Path.implode path) Output.ml_output true (File.read path);

fun evaluate pr verbose (ref_name, r) txt = NAMED_CRITICAL "ML" (fn () =>

  let

    val _ = r := NONE;

    val _ = ML_wrapper pr verbose ("val _ = (" ^ ref_name ^ " := SOME (fn () => " ^ txt ^ "))");

  in (case ! r of NONE => error ("Bad evaluation for " ^ ref_name) | SOME e => e) end) ();

(* basic antiquotations *)

local

fun context x = (Scan.state >> Context.proof_of) x;

val _ = value_antiq "context" (Scan.succeed ("context", "ML_Context.the_local_context ()"));

val _ = inline_antiq "sort" (context -- Scan.lift Args.name >> (fn (ctxt, s) =>

  ML_Syntax.atomic (ML_Syntax.print_sort (Syntax.read_sort ctxt s))));

val _ = inline_antiq "typ" (Args.typ >> (ML_Syntax.atomic o ML_Syntax.print_typ));

val _ = inline_antiq "term" (Args.term >> (ML_Syntax.atomic o ML_Syntax.print_term));

val _ = inline_antiq "prop" (Args.prop >> (ML_Syntax.atomic o ML_Syntax.print_term));

val _ = value_antiq "ctyp" (Args.typ >> (fn T =>

  ("ctyp",

    "Thm.ctyp_of (ML_Context.the_context ()) " ^ ML_Syntax.atomic (ML_Syntax.print_typ T))));

val _ = value_antiq "cterm" (Args.term >> (fn t =>

  ("cterm",

    "Thm.cterm_of (ML_Context.the_context ()) " ^ ML_Syntax.atomic (ML_Syntax.print_term t))));

val _ = value_antiq "cprop" (Args.prop >> (fn t =>

  ("cprop",

    "Thm.cterm_of (ML_Context.the_context ()) " ^ ML_Syntax.atomic (ML_Syntax.print_term t))));

fun type_ syn = (context -- Scan.lift Args.name >> (fn (ctxt, c) =>

    #1 (Term.dest_Type (ProofContext.read_tyname ctxt c))

    |> syn ? Sign.base_name

    |> ML_Syntax.print_string));

val _ = inline_antiq "type_name" (type_ false);

val _ = inline_antiq "type_syntax" (type_ true);

fun const syn = (Scan.state >> Context.proof_of) -- Scan.lift Args.name >> (fn (ctxt, c) =>

  #1 (Term.dest_Const (ProofContext.read_const_proper ctxt c))

  |> syn ? ProofContext.const_syntax_name ctxt

  |> ML_Syntax.print_string);

val _ = inline_antiq "const_name" (const false);

val _ = inline_antiq "const_syntax" (const true);

val _ = inline_antiq "const"

  ((Scan.state >> Context.proof_of) -- Scan.lift Args.name --

    Scan.optional (Scan.lift (Args.$$$ "(") |-- Args.enum1 "," Args.typ --| Scan.lift (Args.$$$ ")")) []

    >> (fn ((ctxt, c), Ts) =>

      let

        val (c, _) = Term.dest_Const (ProofContext.read_const_proper ctxt c);

      in ML_Syntax.atomic (ML_Syntax.print_term (ProofContext.mk_const ctxt (c, Ts))) end));

in val _ = () end;

(** fact references **)

fun thm name = ProofContext.get_thm (the_local_context ()) name;

fun thms name = ProofContext.get_thms (the_local_context ()) name;

local

fun print_interval (Facts.FromTo arg) =

      "Facts.FromTo " ^ ML_Syntax.print_pair ML_Syntax.print_int ML_Syntax.print_int arg

  | print_interval (Facts.From i) = "Facts.From " ^ ML_Syntax.print_int i

  | print_interval (Facts.Single i) = "Facts.Single " ^ ML_Syntax.print_int i;

fun thm_sel name_pos =

  Scan.option Args.thm_sel >> (fn sel => "Facts.Named " ^

    ML_Syntax.print_pair (ML_Syntax.print_pair ML_Syntax.print_string ML_Syntax.print_position)

      (ML_Syntax.print_option (ML_Syntax.print_list print_interval)) (name_pos, sel));

fun thm_antiq kind get = value_antiq kind

  (Scan.lift (Args.position Args.name :-- thm_sel) >> (fn ((name, _), sel) =>

    (name, get ^ " (ML_Context.the_local_context ()) " ^ ML_Syntax.atomic sel)));

in

val _ = add_keywords ["(", ")", "-", ","];

val _ = thm_antiq "thm" "ProofContext.get_fact_single";

val _ = thm_antiq "thms" "ProofContext.get_fact";

end;

val _ = proj_value_antiq "cpat" (Scan.lift Args.name >>

    (fn name => ("cpat",

      "Thm.cterm_of (ML_Context.the_context ()) (Syntax.read_term \

      \(ProofContext.set_mode ProofContext.mode_pattern (ML_Context.the_local_context ()))"

      ^ ML_Syntax.print_string name ^ ")", "")));

(*final declarations of this structure!*)

nonfix >>;

fun >> f = change_theory f;

end;

structure Basic_ML_Context: BASIC_ML_CONTEXT = ML_Context;

open Basic_ML_Context;