(*  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: binding -> (string -> Proof.context -> Proof.context) -> theory -> theory

   val intern_command: theory -> xstring -> string

   val defined_command: theory -> string -> bool

   val intern_option: theory -> xstring -> string

   val defined_option: theory -> string -> bool

   val print_antiquotations: Proof.context -> unit

   val antiquotation: binding -> 'a context_parser ->

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

       theory -> theory

   val boolean: string -> bool

   val integer: string -> int

   datatype markup = Markup | MarkupEnv | Verbatim

   val modes: string list Unsynchronized.ref

   val eval_antiq: Scan.lexicon -> Toplevel.state -> Symbol_Pos.T list * Position.range -> string

   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 list -> 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 = Attrib.setup_config_bool (Binding.name "thy_output_display") (fn _ => ! display_default);

 val quotes = Attrib.setup_config_bool (Binding.name "thy_output_quotes") (fn _ => ! quotes_default);

 val indent = Attrib.setup_config_int (Binding.name "thy_output_indent") (fn _ => ! indent_default);

 val source = Attrib.setup_config_bool (Binding.name "thy_output_source") (fn _ => ! source_default);

 val break = Attrib.setup_config_bool (Binding.name "thy_output_break") (fn _ => ! break_default);

 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 **)

 structure Antiquotations = Theory_Data

 (

   type T =

     (Args.src -> Toplevel.state -> Proof.context -> string) Name_Space.table *

       (string -> Proof.context -> Proof.context) Name_Space.table;

   val empty : T =

     (Name_Space.empty_table Isabelle_Markup.doc_antiquotationN,

       Name_Space.empty_table Isabelle_Markup.doc_antiquotation_optionN);

   val extend = I;

   fun merge ((commands1, options1), (commands2, options2)) : T =

     (Name_Space.merge_tables (commands1, commands2),

       Name_Space.merge_tables (options1, options2));

 );

 fun add_command name cmd thy =

   thy |> Antiquotations.map

     (apfst

       (Name_Space.define

         (Proof_Context.init_global thy) true (Sign.naming_of thy) (name, cmd) #> snd));

 fun add_option name opt thy =

   thy |> Antiquotations.map

     (apsnd

       (Name_Space.define

         (Proof_Context.init_global thy) true (Sign.naming_of thy) (name, opt) #> snd));

 val intern_command = Name_Space.intern o #1 o #1 o Antiquotations.get;

 val defined_command = Symtab.defined o #2 o #1 o Antiquotations.get;

 val intern_option = Name_Space.intern o #1 o #2 o Antiquotations.get;

 val defined_option = Symtab.defined o #2 o #2 o Antiquotations.get;

 fun command src state ctxt =

   let

     val thy = Proof_Context.theory_of ctxt;

     val ((xname, _), pos) = Args.dest_src src;

     val (name, f) = Name_Space.check ctxt (#1 (Antiquotations.get thy)) (xname, pos);

   in

     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 ((xname, pos), s) ctxt =

   let

     val thy = Proof_Context.theory_of ctxt;

     val (_, opt) = Name_Space.check ctxt (#2 (Antiquotations.get thy)) (xname, pos);

   in opt s ctxt end;

 fun print_antiquotations ctxt =

   let

     val thy = Proof_Context.theory_of ctxt;

     val (commands, options) = Antiquotations.get thy;

     val command_names = map #1 (Name_Space.extern_table ctxt commands);

     val option_names = map #1 (Name_Space.extern_table ctxt options);

   in

     [Pretty.big_list "document antiquotations:" (map Pretty.str command_names),

       Pretty.big_list "document antiquotation options:" (map Pretty.str option_names)]

     |> 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.position 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_antiq lex state (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;

 fun eval_antiquote lex state (txt, pos) =

   let

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

       | expand (Antiquote.Antiq antiq) = eval_antiq lex state antiq

       | 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 (update (op =)) 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 (fn () => "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 toks =

   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_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_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 =

       Source.of_list (filter_out Token.is_semicolon toks)

       |> 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 _ =

   Context.>> (Context.map_theory

    (add_option (Binding.name "show_types") (Config.put show_types o boolean) #>

     add_option (Binding.name "show_sorts") (Config.put show_sorts o boolean) #>

     add_option (Binding.name "show_structs") (Config.put show_structs o boolean) #>

     add_option (Binding.name "show_question_marks") (Config.put show_question_marks o boolean) #>

     add_option (Binding.name "show_abbrevs") (Config.put show_abbrevs o boolean) #>

     add_option (Binding.name "names_long") (Config.put Name_Space.names_long o boolean) #>

     add_option (Binding.name "names_short") (Config.put Name_Space.names_short o boolean) #>

     add_option (Binding.name "names_unique") (Config.put Name_Space.names_unique o boolean) #>

     add_option (Binding.name "eta_contract") (Config.put Syntax_Trans.eta_contract o boolean) #>

     add_option (Binding.name "display") (Config.put display o boolean) #>

     add_option (Binding.name "break") (Config.put break o boolean) #>

     add_option (Binding.name "quotes") (Config.put quotes o boolean) #>

     add_option (Binding.name "mode") (add_wrapper o Print_Mode.with_modes o single) #>

     add_option (Binding.name "margin") (add_wrapper o setmp_CRITICAL Pretty.margin_default o integer) #>

     add_option (Binding.name "indent") (Config.put indent o integer) #>

     add_option (Binding.name "source") (Config.put source o boolean) #>

     add_option (Binding.name "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 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 (Proof_Context.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.read_term (Proof_Context.set_mode Proof_Context.mode_abbrev ctxt) s;

     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 (Proof_Context.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 Proof_Context.pretty_term_abbrev ctxt' eq end;

 fun pretty_class ctxt =

   Pretty.str o Proof_Context.extern_class ctxt o Proof_Context.read_class ctxt;

 fun pretty_type ctxt s =

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

   in Pretty.str (Proof_Context.extern_type ctxt name) end;

 fun pretty_prf full ctxt = Proof_Syntax.pretty_proof_of ctxt full;

 fun pretty_theory ctxt name =

   (Theory.requires (Proof_Context.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 _ =

   Context.>> (Context.map_theory

    (basic_entities_style (Binding.name "thm") (Term_Style.parse -- Attrib.thms) pretty_thm_style #>

     basic_entity (Binding.name "prop") (Term_Style.parse -- Args.prop) pretty_term_style #>

     basic_entity (Binding.name "term") (Term_Style.parse -- Args.term) pretty_term_style #>

     basic_entity (Binding.name "term_type") (Term_Style.parse -- Args.term) pretty_term_typ #>

     basic_entity (Binding.name "typeof") (Term_Style.parse -- Args.term) pretty_term_typeof #>

     basic_entity (Binding.name "const") (Args.const_proper false) pretty_const #>

     basic_entity (Binding.name "abbrev") (Scan.lift Args.name_source) pretty_abbrev #>

     basic_entity (Binding.name "typ") Args.typ_abbrev Syntax.pretty_typ #>

     basic_entity (Binding.name "class") (Scan.lift Args.name_source) pretty_class #>

     basic_entity (Binding.name "type") (Scan.lift Args.name) pretty_type #>

     basic_entity (Binding.name "text") (Scan.lift Args.name) pretty_text #>

     basic_entities (Binding.name "prf") Attrib.thms (pretty_prf false) #>

     basic_entities (Binding.name "full_prf") Attrib.thms (pretty_prf true) #>

     basic_entity (Binding.name "theory") (Scan.lift Args.name) pretty_theory #>

     basic_entities_style (Binding.name "thm_style")

       (Term_Style.parse_bare -- Attrib.thms) pretty_thm_style #>

     basic_entity (Binding.name "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 _ =

   Context.>> (Context.map_theory

    (goal_state (Binding.name "goals") true #>

     goal_state (Binding.name "subgoals") false));

 end;

 (* embedded lemma *)

 val _ = Keyword.declare "by" NONE;  (*overlap with command category*)

 val _ =

   Context.>> (Context.map_theory

    (antiquotation (Binding.name "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));

         (* FIXME check proof!? *)

         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 *)

 val verb_text =

   split_lines

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

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

 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 verb_text)));

 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 _ =

   Context.>> (Context.map_theory

    (ml_text (Binding.name "ML") (ml_enclose "fn _ => (" ");") #>

     ml_text (Binding.name "ML_op") (ml_enclose "fn _ => (op " ");") #>

     ml_text (Binding.name "ML_type") (ml_enclose "val _ = NONE : (" ") option;") #>

     ml_text (Binding.name "ML_struct")

       (ml_enclose "functor XXX() = struct structure XX = " " end;") #>

     ml_text (Binding.name "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))))) #>

     ml_text (Binding.name "ML_text") (K (K []))));

 end;

 (* files *)

 val _ =

   Context.>> (Context.map_theory

    (antiquotation (Binding.name "file") (Scan.lift Args.name)

     (fn _ => fn path =>

       if File.exists (Path.explode path) then verb_text path

       else error ("Bad file: " ^ quote path))));

 end;