(*  Title:      Pure/Thy/thy_output.ML

    Author:     Markus Wenzel, TU Muenchen

Theory document output with antiquotations.

*)

signature THY_OUTPUT =

sig

  val display_default: bool Unsynchronized.ref

  val quotes_default: bool Unsynchronized.ref

  val indent_default: int Unsynchronized.ref

  val source_default: bool Unsynchronized.ref

  val break_default: bool Unsynchronized.ref

  val display: bool Config.T

  val quotes: bool Config.T

  val indent: int Config.T

  val source: bool Config.T

  val break: bool Config.T

  val add_wrapper: ((unit -> string) -> unit -> string) -> Proof.context -> Proof.context

  val add_option: string -> (string -> Proof.context -> Proof.context) -> unit

  val defined_command: string -> bool

  val defined_option: string -> bool

  val print_antiquotations: unit -> unit

  val boolean: string -> bool

  val integer: string -> int

  val antiquotation: string -> 'a context_parser ->

    ({source: Args.src, state: Toplevel.state, context: Proof.context} -> 'a -> string) -> unit

  datatype markup = Markup | MarkupEnv | Verbatim

  val modes: string list Unsynchronized.ref

  val eval_antiquote: Scan.lexicon -> Toplevel.state -> Symbol_Pos.text * Position.T -> string

  val present_thy: Scan.lexicon -> (string -> string list) -> (markup -> string -> bool) ->

    (Toplevel.transition * Toplevel.state) list -> (Token.T, 'a) Source.source -> Buffer.T

  val pretty_text: Proof.context -> string -> Pretty.T

  val pretty_term: Proof.context -> term -> Pretty.T

  val pretty_thm: Proof.context -> thm -> Pretty.T

  val str_of_source: Args.src -> string

  val maybe_pretty_source: (Proof.context -> 'a -> Pretty.T) -> Proof.context ->

    Args.src -> 'a list -> Pretty.T list

  val output: Proof.context -> Pretty.T list -> string

end;

structure Thy_Output: THY_OUTPUT =

struct

(** global options **)

val display_default = Unsynchronized.ref false;

val quotes_default = Unsynchronized.ref false;

val indent_default = Unsynchronized.ref 0;

val source_default = Unsynchronized.ref false;

val break_default = Unsynchronized.ref false;

val (display, setup_display) = Attrib.config_bool "thy_output_display" (fn _ => ! display_default);

val (quotes, setup_quotes) = Attrib.config_bool "thy_output_quotes" (fn _ => ! quotes_default);

val (indent, setup_indent) = Attrib.config_int "thy_output_indent" (fn _ => ! indent_default);

val (source, setup_source) = Attrib.config_bool "thy_output_source" (fn _ => ! source_default);

val (break, setup_break) = Attrib.config_bool "thy_output_break" (fn _ => ! break_default);

val _ = Context.>> (Context.map_theory

 (setup_display #> setup_quotes #> setup_indent #> setup_source #> setup_break));

structure Wrappers = Proof_Data

(

  type T = ((unit -> string) -> unit -> string) list;

  fun init _ = [];

);

fun add_wrapper wrapper = Wrappers.map (cons wrapper);

val wrap = Wrappers.get #> fold (fn wrapper => fn f => wrapper f);

(** maintain global antiquotations **)

local

val global_commands =

  Unsynchronized.ref

    (Symtab.empty: (Args.src -> Toplevel.state -> Proof.context -> string) Symtab.table);

val global_options =

  Unsynchronized.ref (Symtab.empty: (string -> Proof.context -> Proof.context) Symtab.table);

fun add_item kind name item tab =

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

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

  Symtab.update (name, item) tab);

in

fun add_command name cmd =

  CRITICAL (fn () => Unsynchronized.change global_commands (add_item "command" name cmd));

fun add_option name opt =

  CRITICAL (fn () => Unsynchronized.change global_options (add_item "option" name opt));

fun defined_command name = Symtab.defined (! global_commands) name;

fun defined_option name = Symtab.defined (! global_options) name;

fun command src =

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

    (case Symtab.lookup (! global_commands) name of

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

    | SOME f =>

       (Position.report pos (Markup.doc_antiq name);

        (fn state => fn ctxt => f src state ctxt handle ERROR msg =>

          cat_error msg ("The error(s) above occurred in document antiquotation: " ^

            quote name ^ Position.str_of pos))))

  end;

fun option (name, s) ctxt =

  (case Symtab.lookup (! global_options) name of

    NONE => error ("Unknown document antiquotation option: " ^ quote name)

  | SOME opt => opt s ctxt);

fun print_antiquotations () =

 [Pretty.big_list "document antiquotation commands:"

    (map Pretty.str (sort_strings (Symtab.keys (! global_commands)))),

  Pretty.big_list "document antiquotation options:"

    (map Pretty.str (sort_strings (Symtab.keys (! global_options))))]

 |> Pretty.chunks |> Pretty.writeln;

end;

fun antiquotation name scan out =

  add_command name

    (fn src => fn state => fn ctxt =>

      let val (x, ctxt') = Args.context_syntax "document antiquotation" scan src ctxt

      in out {source = src, state = state, context = ctxt'} x end);

(** syntax of antiquotations **)

(* option values *)

fun boolean "" = true

  | boolean "true" = true

  | boolean "false" = false

  | boolean s = error ("Bad boolean value: " ^ quote s);

fun integer s =

  let

    fun int ss =

      (case Library.read_int ss of (i, []) => i

      | _ => error ("Bad integer value: " ^ quote s));

  in (case Symbol.explode s of "-" :: ss => ~ (int ss) | ss => int ss) end;

(* outer syntax *)

local

val property =

  Parse.xname -- Scan.optional (Parse.$$$ "=" |-- Parse.!!! Parse.xname) "";

val properties =

  Scan.optional (Parse.$$$ "[" |-- Parse.!!! (Parse.enum "," property --| Parse.$$$ "]")) [];

in

val antiq =

  Parse.!!!

    (Parse.position Parse.liberal_name -- properties -- Args.parse --| Scan.ahead Parse.eof)

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

end;

(* eval_antiquote *)

val modes = Unsynchronized.ref ([]: string list);

fun eval_antiquote lex state (txt, pos) =

  let

    fun expand (Antiquote.Text ss) = Symbol_Pos.content ss

      | expand (Antiquote.Antiq (ss, (pos, _))) =

          let

            val (opts, src) = Token.read_antiq lex antiq (ss, pos);

            fun cmd ctxt = wrap ctxt (fn () => command src state ctxt) ();

            val preview_ctxt = fold option opts (Toplevel.presentation_context_of state);

            val print_ctxt = Context_Position.set_visible false preview_ctxt;

            val _ = cmd preview_ctxt;

          in Print_Mode.with_modes (! modes @ Latex.modes) (fn () => cmd print_ctxt) () end

      | expand (Antiquote.Open _) = ""

      | expand (Antiquote.Close _) = "";

    val ants = Antiquote.read (Symbol_Pos.explode (txt, pos), pos);

  in

    if Toplevel.is_toplevel state andalso not (forall Antiquote.is_text ants) then

      error ("Unknown context -- cannot expand document antiquotations" ^ Position.str_of pos)

    else implode (map expand ants)

  end;

(** present theory source **)

(*NB: arranging white space around command spans is a black art.*)

(* presentation tokens *)

datatype token =

    NoToken

  | BasicToken of Token.T

  | MarkupToken of string * (string * Position.T)

  | MarkupEnvToken of string * (string * Position.T)

  | VerbatimToken of string * Position.T;

fun output_token lex state =

  let val eval = eval_antiquote lex state in

    fn NoToken => ""

     | BasicToken tok => Latex.output_basic tok

     | MarkupToken (cmd, txt) => Latex.output_markup cmd (eval txt)

     | MarkupEnvToken (cmd, txt) => Latex.output_markup_env cmd (eval txt)

     | VerbatimToken txt => Latex.output_verbatim (eval txt)

  end;

fun basic_token pred (BasicToken tok) = pred tok

  | basic_token _ _ = false;

val improper_token = basic_token (not o Token.is_proper);

val comment_token = basic_token Token.is_comment;

val blank_token = basic_token Token.is_blank;

val newline_token = basic_token Token.is_newline;

(* command spans *)

type command = string * Position.T * string list;   (*name, position, tags*)

type source = (token * (string * int)) list;        (*token, markup flag, meta-comment depth*)

datatype span = Span of command * (source * source * source * source) * bool;

fun make_span cmd src =

  let

    fun take_newline (tok :: toks) =

          if newline_token (fst tok) then ([tok], toks, true)

          else ([], tok :: toks, false)

      | take_newline [] = ([], [], false);

    val (((src_prefix, src_main), src_suffix1), (src_suffix2, src_appendix, newline)) =

      src

      |> take_prefix (improper_token o fst)

      ||>> take_suffix (improper_token o fst)

      ||>> take_prefix (comment_token o fst)

      ||> take_newline;

  in Span (cmd, (src_prefix, src_main, src_suffix1 @ src_suffix2, src_appendix), newline) end;

(* present spans *)

local

fun err_bad_nesting pos =

  error ("Bad nesting of commands in presentation" ^ pos);

fun edge which f (x: string option, y) =

  if x = y then I

  else (case which (x, y) of NONE => I | SOME txt => Buffer.add (f txt));

val begin_tag = edge #2 Latex.begin_tag;

val end_tag = edge #1 Latex.end_tag;

fun open_delim delim e = edge #2 Latex.begin_delim e #> delim #> edge #2 Latex.end_delim e;

fun close_delim delim e = edge #1 Latex.begin_delim e #> delim #> edge #1 Latex.end_delim e;

in

fun present_span lex default_tags span state state'

    (tag_stack, active_tag, newline, buffer, present_cont) =

  let

    val present = fold (fn (tok, (flag, 0)) =>

        Buffer.add (output_token lex state' tok)

        #> Buffer.add flag

      | _ => I);

    val Span ((cmd_name, cmd_pos, cmd_tags), srcs, span_newline) = span;

    val (tag, tags) = tag_stack;

    val tag' = try hd (fold Keyword.update_tags cmd_tags (the_list tag));

    val active_tag' =

      if is_some tag' then tag'

      else if cmd_name = "end" andalso not (Toplevel.is_toplevel state') then NONE

      else try hd (default_tags cmd_name);

    val edge = (active_tag, active_tag');

    val newline' =

      if is_none active_tag' then span_newline else newline;

    val nesting = Toplevel.level state' - Toplevel.level state;

    val tag_stack' =

      if nesting = 0 andalso not (Toplevel.is_proof state) then tag_stack

      else if nesting >= 0 then (tag', replicate nesting tag @ tags)

      else

        (case drop (~ nesting - 1) tags of

          tgs :: tgss => (tgs, tgss)

        | [] => err_bad_nesting (Position.str_of cmd_pos));

    val buffer' =

      buffer

      |> end_tag edge

      |> close_delim (fst present_cont) edge

      |> snd present_cont

      |> open_delim (present (#1 srcs)) edge

      |> begin_tag edge

      |> present (#2 srcs);

    val present_cont' =

      if newline then (present (#3 srcs), present (#4 srcs))

      else (I, present (#3 srcs) #> present (#4 srcs));

  in (tag_stack', active_tag', newline', buffer', present_cont') end;

fun present_trailer ((_, tags), active_tag, _, buffer, present_cont) =

  if not (null tags) then err_bad_nesting " at end of theory"

  else

    buffer

    |> end_tag (active_tag, NONE)

    |> close_delim (fst present_cont) (active_tag, NONE)

    |> snd present_cont;

end;

(* present_thy *)

datatype markup = Markup | MarkupEnv | Verbatim;

local

val space_proper =

  Scan.one Token.is_blank -- Scan.many Token.is_comment -- Scan.one Token.is_proper;

val is_improper = not o (Token.is_proper orf Token.is_begin_ignore orf Token.is_end_ignore);

val improper = Scan.many is_improper;

val improper_end = Scan.repeat (Scan.unless space_proper (Scan.one is_improper));

val blank_end = Scan.repeat (Scan.unless space_proper (Scan.one Token.is_blank));

val opt_newline = Scan.option (Scan.one Token.is_newline);

val ignore =

  Scan.depend (fn d => opt_newline |-- Scan.one Token.is_begin_ignore

    >> pair (d + 1)) ||

  Scan.depend (fn d => Scan.one Token.is_end_ignore --|

    (if d = 0 then Scan.fail_with (K "Bad nesting of meta-comments") else opt_newline)

    >> pair (d - 1));

val tag = (improper -- Parse.$$$ "%" -- improper) |-- Parse.!!! (Parse.tag_name --| blank_end);

val locale =

  Scan.option ((Parse.$$$ "(" -- improper -- Parse.$$$ "in") |--

    Parse.!!! (improper |-- Parse.xname --| (improper -- Parse.$$$ ")")));

in

fun present_thy lex default_tags is_markup command_results src =

  let

    (* tokens *)

    val ignored = Scan.state --| ignore

      >> (fn d => (NONE, (NoToken, ("", d))));

    fun markup mark mk flag = Scan.peek (fn d =>

      improper |--

        Parse.position

          (Scan.one (Token.is_kind Token.Command andf is_markup mark o Token.content_of)) --

      Scan.repeat tag --

      Parse.!!!! ((improper -- locale -- improper) |-- Parse.doc_source --| improper_end)

      >> (fn (((tok, pos), tags), txt) =>

        let val name = Token.content_of tok

        in (SOME (name, pos, tags), (mk (name, txt), (flag, d))) end));

    val command = Scan.peek (fn d =>

      Parse.position (Scan.one (Token.is_kind Token.Command)) --

      Scan.repeat tag

      >> (fn ((tok, pos), tags) =>

        let val name = Token.content_of tok

        in (SOME (name, pos, tags), (BasicToken tok, (Latex.markup_false, d))) end));

    val cmt = Scan.peek (fn d =>

      Parse.$$$ "--" |-- Parse.!!!! (improper |-- Parse.doc_source)

      >> (fn txt => (NONE, (MarkupToken ("cmt", txt), ("", d)))));

    val other = Scan.peek (fn d =>

       Parse.not_eof >> (fn tok => (NONE, (BasicToken tok, ("", d)))));

    val token =

      ignored ||

      markup Markup MarkupToken Latex.markup_true ||

      markup MarkupEnv MarkupEnvToken Latex.markup_true ||

      markup Verbatim (VerbatimToken o #2) "" ||

      command || cmt || other;

    (* spans *)

    val is_eof = fn (_, (BasicToken x, _)) => Token.is_eof x | _ => false;

    val stopper = Scan.stopper (K (NONE, (BasicToken Token.eof, ("", 0)))) is_eof;

    val cmd = Scan.one (is_some o fst);

    val non_cmd = Scan.one (is_none o fst andf not o is_eof) >> #2;

    val comments = Scan.many (comment_token o fst o snd);

    val blank = Scan.one (blank_token o fst o snd);

    val newline = Scan.one (newline_token o fst o snd);

    val before_cmd =

      Scan.option (newline -- comments) --

      Scan.option (newline -- comments) --

      Scan.option (blank -- comments) -- cmd;

    val span =

      Scan.repeat non_cmd -- cmd --

        Scan.repeat (Scan.unless before_cmd non_cmd) --

        Scan.option (newline >> (single o snd))

      >> (fn (((toks1, (cmd, tok2)), toks3), tok4) =>

          make_span (the cmd) (toks1 @ (tok2 :: (toks3 @ the_default [] tok4))));

    val spans =

      src

      |> Source.filter (not o Token.is_semicolon)

      |> Source.source' 0 Token.stopper (Scan.error (Scan.bulk token)) NONE

      |> Source.source stopper (Scan.error (Scan.bulk span)) NONE

      |> Source.exhaust;

    (* present commands *)

    fun present_command tr span st st' =

      Toplevel.setmp_thread_position tr (present_span lex default_tags span st st');

    fun present _ [] = I

      | present st (((tr, st'), span) :: rest) = present_command tr span st st' #> present st' rest;

  in

    if length command_results = length spans then

      ((NONE, []), NONE, true, Buffer.empty, (I, I))

      |> present Toplevel.toplevel (command_results ~~ spans)

      |> present_trailer

    else error "Messed-up outer syntax for presentation"

  end;

end;

(** setup default output **)

(* options *)

val _ = add_option "show_types" (Config.put show_types o boolean);

val _ = add_option "show_sorts" (Config.put show_sorts o boolean);

val _ = add_option "show_structs" (Config.put show_structs o boolean);

val _ = add_option "show_question_marks" (Config.put show_question_marks o boolean);

val _ = add_option "long_names" (add_wrapper o setmp_CRITICAL Name_Space.long_names o boolean);

val _ = add_option "short_names" (add_wrapper o setmp_CRITICAL Name_Space.short_names o boolean);

val _ = add_option "unique_names" (add_wrapper o setmp_CRITICAL Name_Space.unique_names o boolean);

val _ = add_option "eta_contract" (Config.put eta_contract o boolean);

val _ = add_option "display" (Config.put display o boolean);

val _ = add_option "break" (Config.put break o boolean);

val _ = add_option "quotes" (Config.put quotes o boolean);

val _ = add_option "mode" (add_wrapper o Print_Mode.with_modes o single);

val _ = add_option "margin" (add_wrapper o setmp_CRITICAL Pretty.margin_default o integer);

val _ = add_option "indent" (Config.put indent o integer);

val _ = add_option "source" (Config.put source o boolean);

val _ = add_option "goals_limit" (Config.put Goal_Display.goals_limit o integer);

(* basic pretty printing *)

fun tweak_line ctxt s =

  if Config.get ctxt display then s else Symbol.strip_blanks s;

fun pretty_text ctxt =

  Pretty.chunks o map Pretty.str o map (tweak_line ctxt) o Library.split_lines;

fun pretty_term ctxt t = Syntax.pretty_term (Variable.auto_fixes t ctxt) t;

fun pretty_thm ctxt = pretty_term ctxt o Thm.full_prop_of;

fun pretty_term_style ctxt (style, t) =

  pretty_term ctxt (style t);

fun pretty_thm_style ctxt (style, th) =

  pretty_term ctxt (style (Thm.full_prop_of th));

fun pretty_term_typ ctxt (style, t) =

  let val t' = style t

  in pretty_term ctxt (Type.constraint (Term.fastype_of t') t') end;

fun pretty_term_typeof ctxt (style, t) =

  Syntax.pretty_typ ctxt (Term.fastype_of (style t));

fun pretty_const ctxt c =

  let

    val t = Const (c, Consts.type_scheme (ProofContext.consts_of ctxt) c)

      handle TYPE (msg, _, _) => error msg;

    val ([t'], _) = Variable.import_terms true [t] ctxt;

  in pretty_term ctxt t' end;

fun pretty_abbrev ctxt s =

  let

    val t = Syntax.parse_term ctxt s |> singleton (ProofContext.standard_infer_types ctxt);

    fun err () = error ("Abbreviated constant expected: " ^ Syntax.string_of_term ctxt t);

    val (head, args) = Term.strip_comb t;

    val (c, T) = Term.dest_Const head handle TERM _ => err ();

    val (U, u) = Consts.the_abbreviation (ProofContext.consts_of ctxt) c

      handle TYPE _ => err ();

    val t' = Term.betapplys (Envir.expand_atom T (U, u), args);

    val eq = Logic.mk_equals (t, t');

    val ctxt' = Variable.auto_fixes eq ctxt;

  in ProofContext.pretty_term_abbrev ctxt' eq end;

fun pretty_class ctxt =

  Pretty.str o Type.extern_class (ProofContext.tsig_of ctxt) o ProofContext.read_class ctxt;

fun pretty_type ctxt s =

  let val Type (name, _) = ProofContext.read_type_name_proper ctxt false s

  in Pretty.str (Type.extern_type (ProofContext.tsig_of ctxt) name) end;

fun pretty_prf full ctxt = Proof_Syntax.pretty_proof_of ctxt full;

fun pretty_theory ctxt name =

  (Theory.requires (ProofContext.theory_of ctxt) name "presentation"; Pretty.str name);

(* default output *)

val str_of_source = space_implode " " o map Token.unparse o #2 o #1 o Args.dest_src;

fun maybe_pretty_source pretty ctxt src xs =

  map (pretty ctxt) xs  (*always pretty in order to exhibit errors!*)

  |> (if Config.get ctxt source then K [pretty_text ctxt (str_of_source src)] else I);

fun output ctxt prts =

  prts

  |> (if Config.get ctxt quotes then map Pretty.quote else I)

  |> (if Config.get ctxt display then

    map (Output.output o Pretty.string_of o Pretty.indent (Config.get ctxt indent))

    #> space_implode "\\isasep\\isanewline%\n"

    #> enclose "\\begin{isabelle}%\n" "%\n\\end{isabelle}"

  else

    map (Output.output o (if Config.get ctxt break then Pretty.string_of else Pretty.str_of))

    #> space_implode "\\isasep\\isanewline%\n"

    #> enclose "\\isa{" "}");

(** concrete antiquotations **)

(* basic entities *)

local

fun basic_entities name scan pretty = antiquotation name scan

  (fn {source, context, ...} => output context o maybe_pretty_source pretty context source);

fun basic_entities_style name scan pretty = antiquotation name scan

  (fn {source, context, ...} => fn (style, xs) =>

    output context

      (maybe_pretty_source (fn ctxt => fn x => pretty ctxt (style, x)) context source xs));

fun basic_entity name scan = basic_entities name (scan >> single);

in

val _ = basic_entities_style "thm" (Term_Style.parse -- Attrib.thms) pretty_thm_style;

val _ = basic_entity "prop" (Term_Style.parse -- Args.prop) pretty_term_style;

val _ = basic_entity "term" (Term_Style.parse -- Args.term) pretty_term_style;

val _ = basic_entity "term_type" (Term_Style.parse -- Args.term) pretty_term_typ;

val _ = basic_entity "typeof" (Term_Style.parse -- Args.term) pretty_term_typeof;

val _ = basic_entity "const" (Args.const_proper false) pretty_const;

val _ = basic_entity "abbrev" (Scan.lift Args.name_source) pretty_abbrev;

val _ = basic_entity "typ" Args.typ_abbrev Syntax.pretty_typ;

val _ = basic_entity "class" (Scan.lift Args.name) pretty_class;

val _ = basic_entity "type" (Scan.lift Args.name) pretty_type;

val _ = basic_entity "text" (Scan.lift Args.name) pretty_text;

val _ = basic_entities "prf" Attrib.thms (pretty_prf false);

val _ = basic_entities "full_prf" Attrib.thms (pretty_prf true);

val _ = basic_entity "theory" (Scan.lift Args.name) pretty_theory;

val _ = basic_entities_style "thm_style" (Term_Style.parse_bare -- Attrib.thms) pretty_thm_style;

val _ = basic_entity "term_style" (Term_Style.parse_bare -- Args.term) pretty_term_style;

end;

(* goal state *)

local

fun proof_state state =

  (case try Toplevel.proof_of state of

    SOME prf => prf

  | _ => error "No proof state");

fun goal_state name main_goal = antiquotation name (Scan.succeed ())

  (fn {state, context = ctxt, ...} => fn () => output ctxt

    [Pretty.chunks

      (Proof.pretty_goals main_goal (Proof.map_context (K ctxt) (proof_state state)))]);

in

val _ = goal_state "goals" true;

val _ = goal_state "subgoals" false;

end;

(* embedded lemma *)

val _ = Keyword.keyword "by";

val _ = antiquotation "lemma"

  (Args.prop -- Scan.lift (Args.$$$ "by" |-- Method.parse -- Scan.option Method.parse))

  (fn {source, context, ...} => fn (prop, methods) =>

    let

      val prop_src =

        (case Args.dest_src source of ((a, arg :: _), pos) => Args.src ((a, [arg]), pos));

      val _ = context

        |> Proof.theorem NONE (K I) [[(prop, [])]]

        |> Proof.global_terminal_proof methods;

    in output context (maybe_pretty_source pretty_term context prop_src [prop]) end);

(* ML text *)

local

fun ml_text name ml = antiquotation name (Scan.lift Args.name_source_position)

  (fn {context, ...} => fn (txt, pos) =>

   (ML_Context.eval_in (SOME context) false pos (ml pos txt);

    Symbol_Pos.content (Symbol_Pos.explode (txt, pos))

    |> (if Config.get context quotes then quote else I)

    |> (if Config.get context display then enclose "\\begin{verbatim}\n" "\n\\end{verbatim}"

    else

      split_lines

      #> map (space_implode "\\verb,|," o map (enclose "\\verb|" "|") o space_explode "|")

      #> space_implode "\\isasep\\isanewline%\n")));

fun ml_enclose bg en pos txt =

  ML_Lex.read Position.none bg @ ML_Lex.read pos txt @ ML_Lex.read Position.none en;

in

val _ = ml_text "ML" (ml_enclose "fn _ => (" ");");

val _ = ml_text "ML_type" (ml_enclose "val _ = NONE : (" ") option;");

val _ = ml_text "ML_struct" (ml_enclose "functor XXX() = struct structure XX = " " end;");

val _ = ml_text "ML_functor"   (* FIXME formal treatment of functor name (!?) *)

  (fn pos => fn txt =>

    ML_Lex.read Position.none ("ML_Env.check_functor " ^

      ML_Syntax.print_string (Symbol_Pos.content (Symbol_Pos.explode (txt, pos)))));

val _ = ml_text "ML_text" (K (K []));

end;

end;