(*
Auxiliary antiquotations for the Cookbook.

*)

structure AntiquoteSetup: sig end =
struct

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

fun ml_val ys txt = "fn " ^
  (case ys of [] => "_" | _ => enclose "(" ")" (commas ys)) ^
  " => (" ^ txt ^ ");";

fun ml_val_open (ys, []) txt = ml_val ys txt
  | ml_val_open (ys, xs) txt =
      ml_val ys ("let open " ^ space_implode " " xs ^ " in " ^ txt ^ " end");

fun output_verbatim f src ctxt x =
  let val txt = f ctxt x
  in
    (if ! ThyOutput.source then str_of_source src else txt)
    |> (if ! ThyOutput.quotes then quote else I)
    |> (if ! ThyOutput.display then enclose "\\begin{alltt}\n" "\n\\end{alltt}"
    else
      split_lines
      #> map (space_implode "\\verb,|," o map (enclose "\\verb|" "|") o space_explode "|")
      #> space_implode "\\isasep\\\\%\n")
  end;

fun output_ml ml = output_verbatim
  (fn ctxt => fn ((txt, p), pos) =>
     (ML_Context.eval_in (SOME ctxt) false pos (ml p txt);
      txt |> Source.of_string |> ML_Lex.source |> Source.exhaust |>
      Chunks.transform_cmts |> implode));

fun transform_char "\\" = "{\\isacharbackslash}"
  | transform_char "$" = "{\\$}"
  | transform_char "{" = "{\\isacharbraceleft}"
  | transform_char "}" = "{\\isacharbraceright}"
  | transform_char x = x;

fun transform_symbol x =
  if Symbol.is_char x then transform_char x else Latex.output_symbols [x];

fun transform_str s = implode (map transform_symbol (Symbol.explode s));

fun ml_pat (rhs, pat) =
  let val pat' = implode (map (fn "\\<dots>" => "_" | s => s)
    (Symbol.explode pat))
  in
    "val " ^ pat' ^ " = " ^ rhs
  end;

fun output_ml_response ml = output_verbatim
  (fn ctxt => fn ((x as (rhs, pat), p), pos) =>
     (ML_Context.eval_in (SOME ctxt) false pos (ml p x);
      transform_str rhs ^ "\n\n" ^
      space_implode "\n" (map (enclose "\\textit{" "}")
        (space_explode "\n" (transform_str pat)))));

fun check_exists ctxt name =
  if File.exists (Path.append (Path.explode ("~~/src")) (Path.explode name)) then ()
  else error ("Source file " ^ quote name ^ " does not exist.")

val _ = ThyOutput.add_commands
  [("ML_open", ThyOutput.args (Scan.lift (OuterParse.position (Args.name --
      (Scan.optional (Args.$$$ "for" |-- OuterParse.!!! (Scan.repeat1 Args.name)) [] --
       Scan.optional (Args.parens (OuterParse.list1 Args.name)) [])))) (output_ml ml_val_open)),
   ("ML_response", ThyOutput.args (Scan.lift (OuterParse.position
        ((Args.name -- Args.name) >> rpair ())))
      (output_ml_response (K ml_pat))),
   ("ML_file", ThyOutput.args (Scan.lift Args.name)
      (ThyOutput.output (fn _ => fn name => (check_exists name; Pretty.str name))))];

end;