(*  Title:      HOL/ex/Cartouche_Examples.thy
    Author:     Makarius
*)

section ‹Some examples with text cartouches›

theory Cartouche_Examples
  imports Main
  keywords "cartouche" :: diag
begin

subsection ‹Regular outer syntax›

text ‹Text cartouches may be used in the outer syntax category ‹text›,
 as alternative to the traditional ‹verbatim› tokens. An example is
 this text block.›  ― ‹The same works for small side-comments.›

notepad
begin
  txt ‹Cartouches work as additional syntax for embedded language tokens
 (types, terms, props) and as a replacement for the ‹altstring› category
 (for literal fact references). For example:›

  fix x y :: 'a
  assume ‹x = y›
  note ‹x = y›
  have ‹x = y› by (rule ‹x = y›)
  from ‹x = y› have ‹x = y› .

  txt ‹Of course, this can be nested inside formal comments and
 antiquotations, e.g. like this @{thm ‹x = y›} or this @{thm sym
 [OF ‹x = y›]}.›

  have ‹x = y›
    by (tactic ‹resolve_tac context @{thms ‹x = y›} 1›)
      ― ‹more cartouches involving ML›
end


subsection ‹Outer syntax: cartouche within command syntax›

ML ‹
 Outer_Syntax.command 🚫‹cartouche› ""
 (Parse.cartouche >> (fn s =>
 Toplevel.keep (fn _ => writeln s)))
 ›

cartouche ‹abc›
cartouche ‹abc ‹αβγ› xzy›


subsection ‹Inner syntax: string literals via cartouche›

ML ‹
 local
 fun mk_char (s, pos) =
 let
 val c =
 if Symbol.is_ascii s then ord s
 else if s = "🚫" then 10
 else error ("String literal contains illegal symbol: " ^ quote s ^ Position.here pos);
 in list_comb (Syntax.const const_syntax‹Char›, String_Syntax.mk_bits_syntax 8 c) end;

 fun mk_string [] = Const (const_syntax‹Nil›, typ‹string›)
 | mk_string (s :: ss) =
 Syntax.const const_syntax‹Cons› $ mk_char s $ mk_string ss;

 in
 fun string_tr content args =
 let fun err () = raise TERM ("string_tr", args) in
 (case args of
 [(c as Const (syntax_const‹_constrain›, _)) $ Free (s, _) $ p] =>
 (case Term_Position.decode_position1 p of
 SOME {pos, ...} => c $ mk_string (content (s, pos)) $ p
 | NONE => err ())
 | _ => err ())
 end;
 end;
 ›

syntax "_cartouche_string" :: ‹cartouche_position → string›  (‹_›)

parse_translation ‹
 [(syntax_const‹_cartouche_string›,
 K (string_tr (Symbol_Pos.cartouche_content o Symbol_Pos.explode)))]
 ›

term ‹‹››
term ‹‹abc››
term ‹‹abc› @ ‹xyz››
term ‹‹🚫››


subsection ‹Alternate outer and inner syntax: string literals›

subsubsection ‹Nested quotes›

syntax "_string_string" :: ‹string_position → string›  (‹_›)

parse_translation ‹
 [(syntax_const‹_string_string›, K (string_tr Lexicon.explode_string))]
 ›

term ‹""›
term ‹"abc"›
term ‹"abc" @ "xyz"›
term ‹"🚫"›
term ‹"\001\010\100"›


subsubsection ‹Further nesting: antiquotations›

ML ‹
 term‹""›;
 term‹"abc"›;
 term‹"abc" @ "xyz"›;
 term‹"🚫"›;
 term‹"\001\010\100"›;
 ›

text ‹
 🚫‹
 (
 term‹""›;
 term‹"abc"›;
 term‹"abc" @ "xyz"›;
 term‹"🚫"›;
 term‹"\001\010\100"›
 )
 ›
 ›


subsubsection ‹Uniform nesting of sub-languages: document source, ML, term, string literals›

text
‹
 🚫‹
 (
 term‹""›;
 term‹"abc"›;
 term‹"abc" @ "xyz"›;
 term‹"🚫"›;
 term‹"\001\010\100"›
 )
 ›
 ›


subsection ‹Proof method syntax: ML tactic expression›

ML ‹
  ML_Tactic:
 
 val set: (Proof.context -> tactic) -> Proof.context -> Proof.context
 val ml_tactic: Input.source -> Proof.context -> tactic
  =
 
 structure Data = Proof_Data(type T = Proof.context -> tactic fun init _ = K no_tac);

 val set = Data.put;

 fun ml_tactic source ctxt =
 let
 val ctxt' = ctxt
 |> Context.proof_map (ML_Context.expression (Input.pos_of source)
 (ML_Lex.read "Theory.local_setup (ML_Tactic.set (fn ctxt: Proof.context => (" @
 ML_Lex.read_source source @ ML_Lex.read ")))"));
 in Data.get ctxt' ctxt end;
 
 ›


subsubsection ‹Explicit version: method with cartouche argument›

method_setup ml_tactic = ‹
 Scan.lift Args.cartouche_input
 >> (fn arg => fn ctxt => SIMPLE_METHOD (ML_Tactic.ml_tactic arg ctxt))
 ›

lemma ‹A ∧ B ⟶ B ∧ A›
  apply (ml_tactic ‹resolve_tac context @{thms impI} 1›)
  apply (ml_tactic ‹eresolve_tac context @{thms conjE} 1›)
  apply (ml_tactic ‹resolve_tac context @{thms conjI} 1›)
  apply (ml_tactic ‹ALLGOALS (assume_tac context)›)
  done

lemma ‹A ∧ B ⟶ B ∧ A› by (ml_tactic ‹blast_tac ctxt 1›)

ML ‹@{lemma ‹A ∧ B ⟶ B ∧ A› by (ml_tactic ‹blast_tac ctxt 1›)}›

text ‹🚫‹@{lemma ‹A ∧ B ⟶ B ∧ A› by (ml_tactic ‹blast_tac ctxt 1›)}››


subsubsection ‹Implicit version: method with special name "cartouche" (dynamic!)›

method_setup "cartouche" = ‹
 Scan.lift Args.cartouche_input
 >> (fn arg => fn ctxt => SIMPLE_METHOD (ML_Tactic.ml_tactic arg ctxt))
 ›

lemma ‹A ∧ B ⟶ B ∧ A›
  apply ‹resolve_tac context @{thms impI} 1›
  apply ‹eresolve_tac context @{thms conjE} 1›
  apply ‹resolve_tac context @{thms conjI} 1›
  apply ‹ALLGOALS (assume_tac context)›
  done

lemma ‹A ∧ B ⟶ B ∧ A›
  by (‹resolve_tac context @{thms impI} 1›,
    ‹eresolve_tac context @{thms conjE} 1›,
    ‹resolve_tac context @{thms conjI} 1›,
    ‹assume_tac context 1›+)


subsection ‹ML syntax›

text ‹Input source with position information:›
ML ‹
 val s: Input.source = ‹abc123def456›;
 Output.information ("Look here!" ^ Position.here (Input.pos_of s));

 ‹abc123def456› |> Input.source_explode |> List.app (fn (s, pos) =>
 if Symbol.is_digit s then Position.report pos Markup.ML_numeral else ());
 ›

end