(* camlp4r q_MLast.cmo ./pa_extfun.cmo *)
(***********************************************************************)
(*                                                                     *)
(*                             Camlp4                                  *)
(*                                                                     *)
(*        Daniel de Rauglaudre, projet Cristal, INRIA Rocquencourt     *)
(*                                                                     *)
(*  Copyright 2001 Institut National de Recherche en Informatique et   *)
(*  Automatique.  Distributed only by permission.                      *)
(*                                                                     *)
(***********************************************************************)

(* $Id$ *)

open Pcaml;
open Spretty;

value not_impl name x =
  let desc =
    if Obj.is_block (Obj.repr x) then
      "tag = " ^ string_of_int (Obj.tag (Obj.repr x))
    else "int_val = " ^ string_of_int (Obj.magic x)
  in
  HVbox [: `S NO ("<pr_r: not impl: " ^ name ^ "; " ^ desc ^ ">") :]
;

value gen_where = ref True;
value old_sequences = ref False;
value expand_declare = ref False;

value no_curried_constructors = ref False;

value constructors_are_curried () =
  not no_curried_constructors.val
;

external is_printable : char -> bool = "caml_is_printable";

value char_escaped =
  fun
  [ '\\' -> "\\\\"
  | '\b' -> "\\b"
  | '\n' -> "\\n"
  | '\r' -> "\\r"
  | '\t' -> "\\t"
  | c ->
      if is_printable c then String.make 1 c
      else do {
        let n = Char.code c in
        let s = String.create 4 in
        String.unsafe_set s 0 '\\';
        String.unsafe_set s 1 (Char.unsafe_chr (48 + n / 100));
        String.unsafe_set s 2 (Char.unsafe_chr (48 + n / 10 mod 10));
        String.unsafe_set s 3 (Char.unsafe_chr (48 + n mod 10));
        s
      } ]
;

value rec list elem el k =
  match el with
  [ [] -> k
  | [x] -> [: `elem x k :]
  | [x :: l] -> [: `elem x [: :]; list elem l k :] ]
;

value rec listws elem sep el k =
  match el with
  [ [] -> k
  | [x] -> [: `elem x k :]
  | [x :: l] -> [: `elem x [: `sep :]; listws elem sep l k :] ]
;

value rec listwbws elem b sep el k =
  match el with
  [ [] -> [: b; k :]
  | [x] -> [: `elem b x k :]
  | [x :: l] -> [: `elem b x [: :]; listwbws elem [: `sep :] sep l k :] ]
;

value is_infix =
  let infixes = Hashtbl.create 73 in
  do {
    List.iter (fun s -> Hashtbl.add infixes s True)
      ["=="; "!="; "+"; "+."; "-"; "-."; "*"; "*."; "/"; "/."; "**";
       "="; "=."; "<>"; "<>."; "<"; "<."; ">"; ">."; "<="; "<=."; ">="; ">=.";
       "^"; "@"; "asr"; "land"; "lor"; "lsl"; "lsr"; "lxor"; "mod"; "or";
       "&&"; "||"; "~-"; "~-."];
    fun s -> try Hashtbl.find infixes s with [ Not_found -> False ]
  }
;

value is_keyword =
  let keywords = Hashtbl.create 301 in
  do {
    List.iter (fun s -> Hashtbl.add keywords s True)
      ["!"; "!="; "#"; "&"; "&&"; "'"; "("; ")"; "*"; "**"; "*."; "+"; "+.";
       ","; "-"; "-."; "->"; "."; ".."; "/"; "/."; ":"; "::"; ":="; ":>";
       ":]"; ";"; "<"; "<="; "<>"; "="; "=="; ">"; ">="; ">}"; "?"; "@"; "[";
       "[:"; "[|"; "]"; "^"; "_"; "`"; "and"; "as"; "asr"; "assert"; "class";
       "constraint"; "declare"; "do"; "done"; "downto"; "else"; "end";
       "exception"; "external"; "for"; "fun"; "functor"; "if"; "in";
       "include"; "inherit"; "initializer"; "land"; "lazy"; "let"; "lor";
       "lsl"; "lsr"; "lxor"; "match"; "method"; "mod"; "module"; "mutable";
       "new"; "object"; "of"; "open"; "parser"; "private"; "rec"; "return";
       "sig"; "struct"; "then"; "to"; "try"; "type"; "value"; "virtual";
       "when"; "where"; "while"; "with"; "{"; "{<"; "|"; "|]"; "||"; "}";
       "~-"; "~-."];
    fun s -> try Hashtbl.find keywords s with [ Not_found -> False ]
  }
;

value has_special_chars v =
  match v.[0] with
  [ 'a'..'z' | 'A'..'Z' | '\192'..'\214' | '\216'..'\246' | '\248'..'\255' |
    '_' ->
      False
  | _ ->
      if String.length v >= 2 && v.[0] == '<' &&
         (v.[1] == '<' || v.[1] == ':')
      then
        False
      else True ]
;

value var_escaped v =
  if v = "" then "$lid:\"\"$"
  else if has_special_chars v || is_infix v then "\\" ^ v
  else if is_keyword v then v ^ "__"
  else v
;

value flag n f = if f then [: `S LR n :] else [: :];

(* default global loc *)

value _loc = (Token.nowhere, Token.nowhere);

(* extensible printers *)

value module_type e k = pr_module_type.pr_fun "top" e "" k;
value module_expr e k = pr_module_expr.pr_fun "top" e "" k;
value sig_item x k = pr_sig_item.pr_fun "top" x "" [: `S RO ";"; k :];
value str_item x k = pr_str_item.pr_fun "top" x "" [: `S RO ";"; k :];
value expr x k = pr_expr.pr_fun "top" x "" k;
value patt x k = pr_patt.pr_fun "top" x "" k;
value ctyp x k = pr_ctyp.pr_fun "top" x "" k;
value expr_fun_args ge = Extfun.apply pr_expr_fun_args.val ge;
value simple_expr x k = pr_expr.pr_fun "simple" x "" k;
value class_sig_item x k =
  pr_class_sig_item.pr_fun "top" x "" [: `S RO ";"; k :]
;
value class_str_item x k =
  pr_class_str_item.pr_fun "top" x "" [: `S RO ";"; k :]
;
value class_type x k = pr_class_type.pr_fun "top" x "" k;
value class_expr x k = pr_class_expr.pr_fun "top" x "" k;


value intloc loc = ((fst loc).Lexing.pos_cnum, (snd loc).Lexing.pos_cnum);

(* type core *)

value rec labels loc b vl k =
  match vl with
  [ [] -> [: b; k :]
  | [v] ->
      [: `HVbox
            [: `HVbox [: :]; `label True b v [: :];
               `LocInfo (intloc(snd loc, snd loc)) (HVbox k) :] :]
  | [v :: l] -> [: `label False b v [: :]; labels loc [: :] l k :] ]
and label is_last b (loc, f, m, t) k =
  let m = flag "mutable" m in
  let k = [: if is_last then [: :] else [: `S RO ";" :]; k :] in
  Hbox
    [: `LocInfo (intloc loc)
          (HVbox
             [: `HVbox [: b; `S LR f; `S LR ":" :];
                `HVbox [: m; `ctyp t [: :] :] :]);
       k :]
;

value rec ctyp_list tel k =
  if constructors_are_curried() then
    listws ctyp (S LR "and") tel k else
  if List.length tel > 1 then
    [: `S LO "("; listws ctyp (S LR "*") tel [: `S RO ")"; k :] :]
  else
    listws ctyp (S LR "*") tel k
;

value rec variants loc b vl k =
  match vl with
  [ [] -> [: b; k :]
  | [v] ->
      [: `HVbox
            [: `HVbox [: :]; `variant b v [: :];
               `LocInfo (intloc(snd loc, snd loc)) (HVbox k) :] :]
  | [v :: l] -> [: `variant b v [: :]; variants loc [: `S LR "|" :] l k :] ]
and variant b (loc, c, tl) k =
  match tl with
  [ [] -> HVbox [: `LocInfo (intloc loc) (HVbox b); `HOVbox [: `S LR c; k :] :]
  | _ ->
      HVbox
        [: `LocInfo (intloc loc) (HVbox b);
           `HOVbox [: `S LR c; `S LR "of"; ctyp_list tl k :] :] ]
;

value rec row_fields b rfl k = listwbws row_field b (S LR "|") rfl k
and row_field b rf k =
  match rf with
  [ MLast.RfTag c ao tl ->
      let c = "`" ^ c in
      match tl with
      [ [] -> HVbox [: b; `HOVbox [: `S LR c; k :] :]
      | _ ->
          let ao = if ao then [: `S LR "&" :] else [: :] in
          HVbox
            [: b; `HOVbox [: `S LR c; `S LR "of"; ao; ctyp_list tl k :] :] ]
  | MLast.RfInh t -> HVbox [: b; `ctyp t k :] ]
;

(* *)

value rec class_longident sl k =
  match sl with
  [ [i] -> HVbox [: `S LR i; k :]
  | [m :: sl] -> HVbox [: `S LR m; `S NO "."; `class_longident sl k :]
  | _ -> HVbox [: `not_impl "class_longident" sl; k :] ]
;

value rec clty_longident sl k =
  match sl with
  [ [i] -> HVbox [: `S LR i; k :]
  | [m :: sl] -> HVbox [: `S LR m; `S NO "."; `clty_longident sl k :]
  | _ -> HVbox [: `not_impl "clty_longident" sl; k :] ]
;

value rec meth_list (ml, v) k =
  match (ml, v) with
  [ ([f], False) -> [: `field f k :]
  | ([], _) -> [: `S LR ".."; k :]
  | ([f :: ml], v) -> [: `field f [: `S RO ";" :]; meth_list (ml, v) k :] ]
and field (lab, t) k =
  HVbox [: `S LR (var_escaped lab); `S LR ":"; `ctyp t k :]
;

value rec data_constructor_app e = match e with
  [ <:expr< $uid:_$ >> | <:expr< $uid:_$ $_$ >> -> True
  | <:expr< $a$ $_$ >> -> data_constructor_app a
  | _ -> False ]
;

value uncurry_expr fe last_arg =
  let rec linearize fe result = match fe with
  [ <:expr< $f$ $x$ >> -> linearize f [ x :: result ]
  | _ -> (fe, result) ] in
  linearize fe [last_arg]
;

(* patterns *)

value uncurry_patt pat last_arg =
  let rec linearize pat result = match pat with
  [ <:patt< $p$ $x$ >> -> linearize p [ x :: result ]
  | _ -> (pat, result) ] in
  linearize pat [last_arg]
;


value rec is_irrefut_patt =
  fun
  [ <:patt< $lid:_$ >> -> True
  | <:patt< () >> -> True
  | <:patt< _ >> -> True
  | <:patt< ($x$ as $y$) >> -> is_irrefut_patt x && is_irrefut_patt y
  | <:patt< { $list:fpl$ } >> ->
      List.for_all (fun (_, p) -> is_irrefut_patt p) fpl
  | <:patt< ($p$ : $_$) >> -> is_irrefut_patt p
  | <:patt< ($list:pl$) >> -> List.for_all is_irrefut_patt pl
  | <:patt< ? $_$ >> -> True
  | <:patt< ? $_$ : ( $p$ ) >> -> is_irrefut_patt p
  | <:patt< ? $_$ : ($p$ = $_$) >> -> is_irrefut_patt p
  | <:patt< ~ $_$ >> -> True
  | <:patt< ~ $_$ : $p$ >> -> is_irrefut_patt p
  | _ -> False ]
;

value rec get_defined_ident =
  fun
  [ <:patt< $_$ . $_$ >> -> []
  | <:patt< _ >> -> []
  | <:patt< $lid:x$ >> -> [x]
  | <:patt< ($p1$ as $p2$) >> -> get_defined_ident p1 @ get_defined_ident p2
  | <:patt< $int:_$ >> -> []
  | (MLast.PaNativeInt _ _ | MLast.PaInt64 _ _ | MLast.PaInt32 _ _) -> []
  | <:patt< $flo:_$ >> -> []
  | <:patt< $str:_$ >> -> []
  | <:patt< $chr:_$ >> -> []
  | <:patt< [| $list:pl$ |] >> -> List.flatten (List.map get_defined_ident pl)
  | <:patt< ($list:pl$) >> -> List.flatten (List.map get_defined_ident pl)
  | <:patt< $uid:_$ >> -> []
  | <:patt< ` $_$ >> -> []
  | <:patt< # $list:_$ >> -> []
  | <:patt< $p1$ $p2$ >> -> get_defined_ident p1 @ get_defined_ident p2
  | <:patt< { $list:lpl$ } >> ->
      List.flatten (List.map (fun (lab, p) -> get_defined_ident p) lpl)
  | <:patt< $p1$ | $p2$ >> -> get_defined_ident p1 @ get_defined_ident p2
  | <:patt< $p1$ .. $p2$ >> -> get_defined_ident p1 @ get_defined_ident p2
  | <:patt< ($p$ : $_$) >> -> get_defined_ident p
  | <:patt< ~ $_$ >> -> []
  | <:patt< ~ $_$ : $p$ >> -> get_defined_ident p
  | <:patt< ? $_$ >> -> []
  | <:patt< ? $_$ : ($p$) >> -> get_defined_ident p
  | <:patt< ? $_$ : ($p$ = $e$) >> -> get_defined_ident p
  | <:patt< $anti:p$ >> -> get_defined_ident p ]
;

value un_irrefut_patt p =
  match get_defined_ident p with
  [ [] -> (<:patt< _ >>, <:expr< () >>)
  | [i] -> (<:patt< $lid:i$ >>, <:expr< $lid:i$ >>)
  | il ->
      let (upl, uel) =
        List.fold_right
          (fun i (upl, uel) ->
             ([<:patt< $lid:i$ >> :: upl], [<:expr< $lid:i$ >> :: uel]))
          il ([], [])
      in
      (<:patt< ($list:upl$) >>, <:expr< ($list:uel$) >>) ]
;            

(* expressions *)

pr_expr_fun_args.val :=
  extfun Extfun.empty with
  [ <:expr< fun [$p$ -> $e$] >> as ge ->
      if is_irrefut_patt p then
        let (pl, e) = expr_fun_args e in
        ([p :: pl], e)
      else ([], ge)
  | ge -> ([], ge) ];

value rec bind_list b pel k =
  match pel with
  [ [pe] -> let_binding b pe k
  | pel ->
      Vbox [: `HVbox [: :]; listwbws let_binding b (S LR "and") pel k :] ]
and let_binding b (p, e) k =
  let (p, e) =
    if is_irrefut_patt p then (p, e)
    else
      let (up, ue) = un_irrefut_patt p in
      (up, <:expr< match $e$ with [ $p$ -> $ue$ ] >>)
  in
  let loc =
    let (bp1, ep1) = MLast.loc_of_patt p in
    let (bp2, ep2) = MLast.loc_of_expr e in
    (min bp1 bp2, max ep1 ep2)
  in
  LocInfo (intloc loc) (BEbox [: let_binding0 [: b; `patt p [: :] :] e [: :]; k :])
and let_binding0 b e k =
  let (pl, e) = expr_fun_args e in
  match e with
  [ <:expr< let $opt:r$ $lid:f$ = fun [ $list:pel$ ] in $e$ >>
    when
      let rec call_f =
        fun
        [ <:expr< $lid:f'$ >> -> f = f'
        | <:expr< $e$ $_$ >> -> call_f e
        | _ -> False ]
      in
      gen_where.val && call_f e ->
      let (pl1, e1) = expr_fun_args <:expr< fun [ $list:pel$ ] >> in
      [: `HVbox [: `HVbox b; `HOVbox (list patt pl [: `S LR "=" :]) :];
         `HVbox
            [: `HOVbox
                  [: `expr e [: :]; `S LR "where"; flag "rec" r; `S LR f;
                     `HVbox (list patt pl1 [: `S LR "=" :]) :];
               `expr e1 k :] :]
  | <:expr< ($e$ : $t$) >> ->
      [: `HVbox
            [: `HVbox b; `HOVbox (list patt pl [: `S LR ":" :]);
               `ctyp t [: `S LR "=" :] :];
         `expr e k :]
  | _ ->
      [: `HVbox [: `HVbox b; `HOVbox (list patt pl [: `S LR "=" :]) :];
         `expr e k :] ]
and match_assoc_list pwel k =
  match pwel with
  [ [pwe] -> match_assoc [: `S LR "[" :] pwe [: `S LR "]"; k :]
  | pel ->
      Vbox
        [: `HVbox [: :];
           listwbws match_assoc [: `S LR "[" :] (S LR "|") pel
             [: `S LR "]"; k :] :] ]
and match_assoc b (p, w, e) k =
  let s =
    let (p, k) =
      match p with
      [ <:patt< ($p$ as $p2$) >> -> (p, [: `S LR "as"; `patt p2 [: :] :])
      | _ -> (p, [: :]) ]
    in
    match w with
    [ Some e1 ->
        [: `HVbox
              [: `HVbox [: :]; `patt p k;
                 `HVbox [: `S LR "when"; `expr e1 [: `S LR "->" :] :] :] :]
    | _ -> [: `patt p [: k; `S LR "->" :] :] ]
  in
  HVbox [: b; `HVbox [: `HVbox s; `expr e k :] :]
;

value label lab = S LR (var_escaped lab);

value field_expr (lab, e) k = HVbox [: `label lab; `S LR "="; `expr e k :];

value rec sequence_loop =
  fun
  [ [<:expr< let $opt:r$ $list:pel$ in $e$ >>] ->
      let el =
        match e with
        [ <:expr< do { $list:el$ } >> -> el
        | _ -> [e] ]
      in
      let r = flag "rec" r in
      [: listwbws (fun b (p, e) k -> let_binding b (p, e) k)
           [: `S LR "let"; r :] (S LR "and") pel [: `S LR "in" :];
         sequence_loop el :]
  | [(<:expr< let $opt:_$ $list:_$ in $_$ >> as e) :: el] ->
      [: `simple_expr e [: `S RO ";" :]; sequence_loop el :]
  | [e] -> [: `expr e [: :] :]
  | [e :: el] -> [: `expr e [: `S RO ";" :]; sequence_loop el :]
  | [] -> [: :] ]
;

value sequence b1 b2 b3 el k =
  BEbox
    [: `BEbox [: b1; b2; `HVbox [: b3; `S LR "do {" :] :];
       `HVbox [: `HVbox [: :]; sequence_loop el :];
       `HVbox [: `S LR "}"; k :] :]
;

value rec let_sequence e =
  match e with
  [ <:expr< do { $list:el$ } >> -> Some el
  | <:expr< let $opt:_$ $list:_$ in $e1$ >> ->
      match let_sequence e1 with
      [ Some _ -> Some [e]
      | None -> None ]
  | _ -> None ]
;

value ifbox b1 b2 b3 e k =
  if old_sequences.val then HVbox [: `HOVbox [: b1; b2; b3 :]; `expr e k :]
  else
    match let_sequence e with
    [ Some el -> sequence b1 b2 b3 el k
    | None -> HVbox [: `BEbox [: b1; b2; b3 :]; `expr e k :] ]
;

value rec type_params sl k =
  list
    (fun (s, vari) k ->
       let b =
         match vari with
         [ (True, False) -> [: `S LO "+" :]
         | (False, True) -> [: `S LO "-" :]
         | _ -> [: :] ]
       in
       HVbox [: b; `S LO "'"; `S LR s; k :])
    sl k
;

value constrain (t1, t2) k =
  HVbox [: `S LR "constraint"; `ctyp t1 [: `S LR "=" :]; `ctyp t2 k :]
;

value type_list b tdl k =
  HVbox
    [: `HVbox [: :];
       listwbws
         (fun b ((_, tn), tp, te, cl) k ->
            let tn = var_escaped tn in
            HVbox
              [: `HVbox [: b; `S LR tn; type_params tp [: `S LR "=" :] :];
                 `ctyp te [: :]; list constrain cl k :])
         b (S LR "and") tdl [: :];
       k :]
;

value external_def s t pl k =
  let ls = list (fun s k -> HVbox [: `S LR ("\"" ^ s ^ "\""); k :]) pl k in
  HVbox
    [: `HVbox [: `S LR "external"; `S LR (var_escaped s); `S LR ":" :];
       `ctyp t [: `S LR "="; ls :] :]
;

value value_description s t k =
  HVbox
    [: `HVbox [: `S LR "value"; `S LR (var_escaped s); `S LR ":" :];
       `ctyp t k :]
;

value typevar s k = HVbox [: `S LR ("'" ^ s); k :];

value rec mod_ident sl k =
  match sl with
  [ [] -> k
  | [s] -> [: `S LR (var_escaped s); k :]
  | [s :: sl] -> [: `S LR s; `S NO "."; mod_ident sl k :] ]
;

value rec module_declaration b mt k =
  match mt with
  [ <:module_type< functor ( $i$ : $t$ ) -> $mt$ >> ->
      module_declaration
        [: `HVbox
              [: b;
                 `HVbox
                    [: `S LO "("; `S LR i; `S LR ":";
                       `module_type t [: `S RO ")" :] :] :] :]
        mt k
  | _ ->
      HVbox
        [: `HVbox [: :];
           `HVbox [: `HVbox [: b; `S LR ":" :]; `module_type mt [: :] :];
           k :] ]
and module_rec_declaration b (n,mt) k =
  HVbox
    [: `HVbox
          [: b; `S LR n; `S LR ":"; `module_type mt [: :] :];
          k :]
and modtype_declaration s mt k =
  HVbox
    [: `HVbox [: :];
       `HVbox
          [: `HVbox [: `S LR "module"; `S LR "type"; `S LR s; `S LR "=" :];
             `module_type mt [: :] :];
       k :]
and with_constraints b icl k =
  HVbox [: `HVbox [: :]; listwbws with_constraint b (S LR "and") icl k :]
and with_constraint b wc k =
  match wc with
  [ <:with_constr< type $p$ $list:al$ = $e$ >> ->
      let params =
        match al with
        [ [] -> [: :]
        | [s] -> [: `S LO "'"; `S LR (fst s) :]
        | sl -> [: `S LO "("; type_params sl [: `S RO ")" :] :] ]
      in
      HVbox
        [: `HVbox
              [: `HVbox b; `S LR "type"; params;
                 mod_ident p [: `S LR "=" :] :];
           `ctyp e k :]
  | <:with_constr< module $sl$ = $me$ >> ->
      HVbox
        [: b; `S LR "module"; mod_ident sl [: `S LR "=" :];
           `module_expr me k :] ]
and module_binding b me k =
  match me with
  [ <:module_expr< functor ($s$ : $mt$) -> $mb$ >> ->
      module_binding
        [: `HVbox
              [: b;
                 `HVbox
                    [: `HVbox [: `S LO "("; `S LR s; `S LR ":" :];
                       `module_type mt [: `S RO ")" :] :] :] :]
        mb k
  | <:module_expr< ( $me$ : $mt$ ) >> ->
      HVbox
        [: `HVbox [: :];
           `HVbox
              [: `HVbox
                    [: `HVbox [: b; `S LR ":" :];
                       `module_type mt [: `S LR "=" :] :];
                 `module_expr me [: :] :];
           k :]
  | _ ->
      HVbox
        [: `HVbox [: :];
           `HVbox [: `HVbox [: b; `S LR "=" :]; `module_expr me [: :] :];
           k :] ]
and module_rec_binding b (n, mt,me) k =
  HVbox
    [: `HVbox [: :];
       `HVbox
         [: `HVbox
            [: `HVbox [: b; `S LR n; `S LR ":" :];
               `module_type mt [: `S LR "=" :] :];
               `module_expr me [: :] :];
       k :]
and class_declaration b ci k =
  class_fun_binding
    [: b; flag "virtual" ci.MLast.ciVir; `S LR ci.MLast.ciNam;
       class_type_parameters ci.MLast.ciPrm :]
    ci.MLast.ciExp k
and class_fun_binding b ce k =
  match ce with
  [ <:class_expr< fun $p$ -> $cfb$ >> ->
      class_fun_binding [: b; `patt p [: :] :] cfb k
  | ce -> HVbox [: `HVbox [: b; `S LR "=" :]; `class_expr ce k :] ]
and class_type_parameters (loc, tpl) =
  match tpl with
  [ [] -> [: :]
  | tpl ->
      [: `S LO "["; listws type_parameter (S RO ",") tpl [: `S RO "]" :] :] ]
and type_parameter tp k = HVbox [: `S LO "'"; `S LR (fst tp); k :]
and simple_expr e k =
  match e with
  [ <:expr< $lid:_$ >> -> expr e k
  | _ -> HVbox [: `S LO "("; `expr e [: `S RO ")"; k :] :] ]
and class_self_patt_opt csp =
  match csp with
  [ Some p -> HVbox [: `S LO "("; `patt p [: `S RO ")" :] :]
  | None -> HVbox [: :] ]
and label lab = S LR (var_escaped lab)
and cvalue b (lab, mf, e) k =
  HVbox
    [: `HVbox [: b; flag "mutable" mf; `label lab; `S LR "=" :]; `expr e k :]
and fun_binding b fb k =
  match fb with
  [ <:expr< fun $p$ -> $e$ >> -> fun_binding [: b; `simple_patt p [: :] :] e k
  | e -> HVbox [: `HVbox [: b; `S LR "=" :]; `expr e k :] ]
and simple_patt p k =
  match p with
  [ <:patt< $lid:_$ >> | <:patt< ~ $_$ : $_$ >> |
    <:patt< ? $_$ : ($_$ $opt:_$) >> -> patt p k
  | _ -> HVbox [: `S LO "("; `patt p [: `S RO ")"; k :] :] ]
and class_signature cs k =
  match cs with
  [ <:class_type< $list:id$ >> -> clty_longident id k
  | <:class_type< $list:id$ [ $list:tl$ ] >> ->
      HVbox
        [: `clty_longident id [: :]; `S LO "[";
           listws ctyp (S RO ",") tl [: `S RO "]"; k :] :]
  | <:class_type< object $opt:cst$ $list:csf$ end >> ->
      let ep = snd (MLast.loc_of_class_type cs) in
      class_self_type [: `S LR "object" :] cst
        [: `HVbox
              [: `HVbox [: :]; list class_sig_item csf [: :];
                 `LocInfo (intloc(ep, ep)) (HVbox [: :]) :];
           `HVbox [: `S LR "end"; k :] :]
  | _ -> HVbox [: `not_impl "class_signature" cs; k :] ]
and class_self_type b cst k =
  BEbox
    [: `HVbox
          [: b;
             match cst with
             [ None -> [: :]
             | Some t -> [: `S LO "("; `ctyp t [: `S RO ")" :] :] ] :];
       k :]
and class_description b ci k =
  HVbox
    [: `HVbox
          [: b; flag "virtual" ci.MLast.ciVir; `S LR ci.MLast.ciNam;
             class_type_parameters ci.MLast.ciPrm; `S LR ":" :];
       `class_type ci.MLast.ciExp k :]
and class_type_declaration b ci k =
  HVbox
    [: `HVbox
          [: b; flag "virtual" ci.MLast.ciVir; `S LR ci.MLast.ciNam;
             class_type_parameters ci.MLast.ciPrm; `S LR "=" :];
       `class_signature ci.MLast.ciExp k :]
;

pr_module_type.pr_levels :=
  [{pr_label = "top"; pr_box s x = HVbox x;
    pr_rules =
      extfun Extfun.empty with
      [ <:module_type< functor ( $s$ : $mt1$ ) -> $mt2$ >> ->
          fun curr next _ k ->
            let head =
              HVbox
                [: `S LR "functor"; `S LO "("; `S LR s; `S LR ":";
                   `module_type mt1 [: `S RO ")" :]; `S LR "->" :]
            in
            [: `head; `module_type mt2 k :]
      | e -> fun curr next dg k -> [: `next e dg k :] ]};
   {pr_label = ""; pr_box s x = HVbox x;
    pr_rules =
      extfun Extfun.empty with
      [ <:module_type< $mt$ with $list:icl$ >> ->
          fun curr next _ k ->
            [: curr mt "" [: :]; `with_constraints [: `S LR "with" :] icl k :]
      | e -> fun curr next dg k -> [: `next e dg k :] ]};
   {pr_label = ""; pr_box s x = HVbox x;
    pr_rules =
      extfun Extfun.empty with
      [ <:module_type< sig $list:s$ end >> as mt ->
          fun curr next _ k ->
            let ep = snd (MLast.loc_of_module_type mt) in
            [: `BEbox
                  [: `S LR "sig";
                     `HVbox
                        [: `HVbox [: :]; list sig_item s [: :];
                           `LocInfo (intloc(ep, ep)) (HVbox [: :]) :];
                     `HVbox [: `S LR "end"; k :] :] :]
      | e -> fun curr next dg k -> [: `next e dg k :] ]};
   {pr_label = ""; pr_box s x = HVbox x;
    pr_rules =
      extfun Extfun.empty with
      [ <:module_type< $mt1$ $mt2$ >> ->
          fun curr next _ k -> [: curr mt1 "" [: :]; `next mt2 "" k :]
      | e -> fun curr next dg k -> [: `next e dg k :] ]};
   {pr_label = ""; pr_box s x = HVbox x;
    pr_rules =
      extfun Extfun.empty with
      [ <:module_type< $mt1$ . $mt2$ >> ->
          fun curr next _ k ->
            [: curr mt1 "" [: `S NO "." :]; `next mt2 "" k :]
      | e -> fun curr next dg k -> [: `next e dg k :] ]};
   {pr_label = ""; pr_box s x = HVbox x;
    pr_rules =
      extfun Extfun.empty with
      [ <:module_type< $lid:s$ >> -> fun curr next _ k -> [: `S LR s; k :]
      | <:module_type< $uid:s$ >> -> fun curr next _ k -> [: `S LR s; k :]
      | <:module_type< ' $s$ >> ->
          fun curr next _ k -> [: `S LR ("'" ^ s); k :]
      | mt ->
          fun curr next _ k ->
            [: `S LO "("; `module_type mt [: `S RO ")"; k :] :] ]}];

pr_module_expr.pr_levels :=
  [{pr_label = "top"; pr_box s x = HVbox x;
    pr_rules =
      extfun Extfun.empty with
      [ <:module_expr< struct $list:s$ end >> as me ->
          fun curr next _ k ->
            let ep = snd (MLast.loc_of_module_expr me) in
            [: `HVbox [: :];
               `HVbox
                  [: `S LR "struct"; list str_item s [: :];
                     `LocInfo (intloc(ep, ep)) (HVbox [: :]) :];
               `HVbox [: `S LR "end"; k :] :]
      | <:module_expr< functor ($s$ : $mt$) -> $me$ >> ->
          fun curr next _ k ->
            let head =
              HVbox
                [: `S LR "functor"; `S LO "("; `S LR s; `S LR ":";
                   `module_type mt [: `S RO ")" :]; `S LR "->" :]
            in
            [: `head; curr me "" k :]
      | e -> fun curr next dg k -> [: `next e dg k :] ]};
   {pr_label = ""; pr_box s x = HOVbox x;
    pr_rules =
      extfun Extfun.empty with
      [ <:module_expr< $me1$ $me2$ >> ->
          fun curr next _ k -> [: curr me1 "" [: :]; `next me2 "" k :]
      | e -> fun curr next dg k -> [: `next e dg k :] ]};
   {pr_label = ""; pr_box s x = HVbox x;
    pr_rules =
      extfun Extfun.empty with
      [ <:module_expr< $me1$ . $me2$ >> ->
          fun curr next _ k ->
            [: curr me1 "" [: `S NO "." :]; `next me2 "" k :]
      | e -> fun curr next dg k -> [: `next e dg k :] ]};
   {pr_label = ""; pr_box s x = HVbox x;
    pr_rules =
      extfun Extfun.empty with
      [ <:module_expr< $uid:s$ >> -> fun curr next _ k -> [: `S LR s; k :]
      | <:module_expr< ( $me$ : $mt$ ) >> ->
          fun curr next _ k ->
            [: `S LO "("; `module_expr me [: `S LR ":" :];
               `module_type mt [: `S RO ")"; k :] :]
      | <:module_expr< struct $list:_$ end >> |
        <:module_expr< functor ($_$ : $_$) -> $_$ >> |
        <:module_expr< $_$ $_$ >> | <:module_expr< $_$ . $_$ >> as me ->
          fun curr next _ k ->
            [: `S LO "("; `module_expr me [: `S RO ")"; k :] :] ]}];

pr_sig_item.pr_levels :=
  [{pr_label = "top";
    pr_box s x = LocInfo (intloc(MLast.loc_of_sig_item s)) (HVbox x);
    pr_rules =
      extfun Extfun.empty with
      [ <:sig_item< type $list:stl$ >> ->
          fun curr next _ k -> [: `type_list [: `S LR "type" :] stl k :]
      | <:sig_item< declare $list:s$ end >> ->
          fun curr next _ k ->
            if expand_declare.val then
              if s = [] then [: `S LR "(* *)" :]
              else [: `HVbox [: :]; list sig_item s [: :] :]
            else
              [: `BEbox
                    [: `S LR "declare";
                       `HVbox [: `HVbox [: :]; list sig_item s [: :] :];
                       `HVbox [: `S LR "end"; k :] :] :]
      | <:sig_item< # $_$ $opt:_$ >> as si ->
          fun curr next _ k -> [: `not_impl "sig_item1" si :]
      | <:sig_item< exception $c$ of $list:tl$ >> ->
          fun curr next _ k ->
            [: `variant [: `S LR "exception" :] (_loc, c, tl) k :]
      | <:sig_item< value $s$ : $t$ >> ->
          fun curr next _ k -> [: `value_description s t k :]
      | <:sig_item< include $mt$ >> ->
          fun curr next _ k -> [: `S LR "include"; `module_type mt k :]
      | <:sig_item< external $s$ : $t$ = $list:pl$ >> ->
          fun curr next _ k -> [: `external_def s t pl k :]
      | <:sig_item< module $s$ : $mt$ >> ->
          fun curr next _ k ->
            [: `module_declaration [: `S LR "module"; `S LR s :] mt k :]
      | <:sig_item< module rec $list:nmts$ >> ->
          fun curr next _ k ->
            [: `HVbox [: :];
               listwbws module_rec_declaration [: `S LR "module rec" :] (S LR "and") nmts
                 k :]
      | <:sig_item< module type $s$ = $mt$ >> ->
          fun curr next _ k -> [: `modtype_declaration s mt k :]
      | <:sig_item< open $sl$ >> ->
          fun curr next _ k -> [: `S LR "open"; mod_ident sl k :]
      | <:sig_item< class $list:cd$ >> ->
          fun curr next _ k ->
            [: `HVbox [: :];
               listwbws class_description [: `S LR "class" :] (S LR "and") cd
                 k :]
      | <:sig_item< class type $list:cd$ >> ->
          fun curr next _ k ->
            [: `HVbox [: :];
               listwbws class_type_declaration
                 [: `S LR "class"; `S LR "type" :] (S LR "and") cd k :]
      | MLast.SgUse _ _ _ ->
          fun curr next _ k -> [: :] ]}];

pr_str_item.pr_levels :=
  [{pr_label = "top";
    pr_box s x = LocInfo (intloc(MLast.loc_of_str_item s)) (HVbox x);
    pr_rules =
      extfun Extfun.empty with
      [ <:str_item< open $i$ >> ->
          fun curr next _ k -> [: `S LR "open"; mod_ident i k :]
      | <:str_item< $exp:e$ >> ->
          fun curr next _ k -> [: `HVbox [: :]; `expr e k :]
      | <:str_item< declare $list:s$ end >> ->
          fun curr next _ k ->
            if expand_declare.val then
              if s = [] then [: `S LR "(* *)" :]
              else [: `HVbox [: :]; list str_item s [: :] :]
            else
              [: `BEbox
                    [: `S LR "declare";
                       `HVbox [: `HVbox [: :]; list str_item s [: :] :];
                       `HVbox [: `S LR "end"; k :] :] :]
      | <:str_item< # $s$ $opt:x$ >> ->
          fun curr next _ k ->
            let s =
              "(* #" ^ s ^ " " ^
                (match x with
                 [ Some <:expr< $str:s$ >> -> "\"" ^ s ^ "\""
                 | _ -> "?" ]) ^
                " *)"
            in
            [: `S LR s :]
      | <:str_item< exception $c$ of $list:tl$ = $b$ >> ->
          fun curr next _ k ->
            match b with
            [ [] -> [: `variant [: `S LR "exception" :] (_loc, c, tl) k :]
            | _ ->
                [: `variant [: `S LR "exception" :] (_loc, c, tl)
                      [: `S LR "=" :];
                   mod_ident b k :] ]
      | <:str_item< include $me$ >> ->
          fun curr next _ k -> [: `S LR "include"; `module_expr me k :]
      | <:str_item< type $list:tdl$ >> ->
          fun curr next _ k -> [: `type_list [: `S LR "type" :] tdl k :]
      | <:str_item< value $opt:rf$ $list:pel$ >> ->
          fun curr next _ k ->
            [: `bind_list [: `S LR "value"; flag "rec" rf :] pel k :]
      | <:str_item< external $s$ : $t$ = $list:pl$ >> ->
          fun curr next _ k -> [: `external_def s t pl k :]
      | <:str_item< module $s$ = $me$ >> ->
          fun curr next _ k ->
            [: `module_binding [: `S LR "module"; `S LR s :] me k :]
      | <:str_item< module rec $list:nmtmes$ >> ->
          fun curr next _ k ->
            [: `HVbox [: :];
               listwbws module_rec_binding [: `S LR "module rec" :] (S LR "and") nmtmes
                 k :]
      | <:str_item< module type $s$ = $mt$ >> ->
          fun curr next _ k ->
            [: `HVbox [: :];
               `HVbox
                  [: `HVbox
                        [: `S LR "module"; `S LR "type"; `S LR s;
                           `S LR "=" :];
                     `module_type mt [: :] :];
               k :]
      | <:str_item< class $list:cd$ >> ->
          fun curr next _ k ->
            [: `HVbox [: :];
               listwbws class_declaration [: `S LR "class" :] (S LR "and") cd
                 k :]
      | <:str_item< class type $list:cd$ >> ->
          fun curr next _ k ->
            [: `HVbox [: :];
               listwbws class_type_declaration
                 [: `S LR "class"; `S LR "type" :] (S LR "and") cd k :]
      | MLast.StUse _ _ _ ->
          fun curr next _ k -> [: :] ]}];

(*
EXTEND_PRINTER
  pr_expr:
    [ "top" (fun e x -> LocInfo (MLast.loc_of_expr e) (HOVbox x))
      [ <:expr< let $rec:r$ $p1$ = $e1$ in $e$ >> ->
          let r = flag "rec" r in
          [: `Vbox
                [: `HVbox [: :];
                   `let_binding [: `S LR "let"; r :] (p1, e1)
                      [: `S LR "in" :];
                   `expr e k :] :]
      | <:expr< let $rec:r$ $list:pel$ in $e$ >> ->
          let r = flag "rec" r in
          [: `Vbox
                [: `HVbox [: :];
                   listwbws (fun b (p, e) k -> let_binding b (p, e) k)
                     [: `S LR "let"; r :] (S LR "and") pel [: `S LR "in" :];
                   `expr e k :] :] ] ]
  ;
END;
*)

pr_expr.pr_levels :=
  [{pr_label = "top"; pr_box e x = LocInfo (intloc(MLast.loc_of_expr e)) (HOVbox x);
    pr_rules =
      extfun Extfun.empty with
      [ <:expr< let $opt:r$ $p1$ = $e1$ in $e$ >> ->
          fun curr next _ k ->
            let r = flag "rec" r in
            [: `Vbox
                  [: `HVbox [: :];
                     `let_binding [: `S LR "let"; r :] (p1, e1)
                        [: `S LR "in" :];
                     `expr e k :] :]
      | <:expr< let $opt:r$ $list:pel$ in $e$ >> ->
          fun curr next _ k ->
            let r = flag "rec" r in
            [: `Vbox
                  [: `HVbox [: :];
                     listwbws (fun b (p, e) k -> let_binding b (p, e) k)
                       [: `S LR "let"; r :] (S LR "and") pel [: `S LR "in" :];
                     `expr e k :] :]
      | <:expr< let module $m$ = $mb$ in $e$ >> ->
          fun curr next _ k ->
            [: `HVbox
                  [: `HVbox [: :];
                     `module_binding
                        [: `S LR "let"; `S LR "module"; `S LR m :] mb
                        [: `S LR "in" :];
                     `expr e k :] :]
      | <:expr< fun [ $list:pel$ ] >> ->
          fun curr next _ k ->
            match pel with
            [ [] -> [: `S LR "fun"; `S LR "[]"; k :]
            | [(p, None, e)] ->
                if is_irrefut_patt p then
                  let (pl, e) = expr_fun_args e in
                  [: `BEbox
                        [: `HOVbox
                              [: `S LR "fun";
                                 list patt [p :: pl] [: `S LR "->" :] :];
                           `expr e k :] :]
                else
                  [: `HVbox [: `S LR "fun ["; `patt p [: `S LR "->" :] :];
                     `expr e [: `S LR "]"; k :] :]
            | _ ->
                [: `Vbox
                      [: `HVbox [: :]; `S LR "fun";
                         listwbws match_assoc [: `S LR "[" :] (S LR "|") pel
                           [: `S LR "]"; k :] :] :] ]
      | <:expr< match $e$ with $p1$ -> $e1$ >> when is_irrefut_patt p1 ->
          fun curr next _ k ->
            [: `BEbox
                  [: `S LR "match"; `expr e [: :];
                     `HVbox [: `S LR "with"; `patt p1 [: `S LR "->" :] :] :];
               `expr e1 k :]
      | <:expr< match $e$ with [ ] >> ->
          fun curr next _ k ->
            [: `HVbox [: :];
               `BEbox
                  [: `S LR "match"; `expr e [: :]; `S LR "with"; `S LR "[]";
                     k :] :]
      | <:expr< match $e$ with [ $list:pel$ ] >> ->
          fun curr next _ k ->
            [: `HVbox [: :];
               `BEbox [: `S LR "match"; `expr e [: :]; `S LR "with" :];
               `match_assoc_list pel k :]
      | <:expr< try $e$ with [ ] >> ->
          fun curr next _ k ->
            [: `HVbox [: :];
               `BEbox
                  [: `S LR "try"; `expr e [: :]; `S LR "with"; `S LR "[]";
                     k :] :]
      | <:expr< try $e$ with $p1$ -> $e1$ >> when is_irrefut_patt p1 ->
          fun curr next _ k ->
            [: `BEbox
                  [: `S LR "try"; `expr e [: :];
                     `HVbox [: `S LR "with"; `patt p1 [: `S LR "->" :] :] :];
               `expr e1 k :]
      | <:expr< try $e$ with [ $list:pel$ ] >> ->
          fun curr next _ k ->
            [: `HVbox [: :];
               `BEbox [: `S LR "try"; `expr e [: :]; `S LR "with" :];
               `match_assoc_list pel k :]
      | <:expr< if $e1$ then $e2$ else $e3$ >> ->
          fun curr next _ k ->
            let (eel, e) =
              elseif e3 where rec elseif e =
                match e with
                [ <:expr< if $e1$ then $e2$ else $e3$ >> ->
                    let (eel, e) = elseif e3 in
                    ([(e1, e2) :: eel], e)
                | _ -> ([], e) ]
            in
            [: `HVbox
                  [: `HVbox [: :];
                     `ifbox [: `S LR "if" :] [: `expr e1 [: :] :]
                        [: `S LR "then" :] e2 [: :];
                     list
                       (fun (e1, e2) k ->
                          ifbox [: `HVbox [: `S LR "else"; `S LR "if" :] :]
                            [: `expr e1 [: :] :] [: `S LR "then" :] e2 k)
                       eel [: :];
                     `ifbox [: `S LR "else" :] [: :] [: :] e k :] :]
      | <:expr< do { $list:el$ } >> when old_sequences.val ->
          fun curr next _ k ->
            let (el, e) =
              match List.rev el with
              [ [e :: el] -> (List.rev el, e)
              | [] -> ([], <:expr< () >>) ]
            in
            [: `HOVCbox
                  [: `HVbox [: :];
                     `BEbox
                        [: `S LR "do";
                           `HVbox
                              [: `HVbox [: :];
                                 list (fun e k -> expr e [: `S RO ";"; k :])
                                   el [: :] :];
                           `S LR "return" :];
                     `expr e k :] :]
      | <:expr< do { $list:el$ } >> ->
          fun curr next _ k -> [: `sequence [: :] [: :] [: :] el k :]
      | <:expr< for $i$ = $e1$ $to:d$ $e2$ do { $list:el$ } >>
        when old_sequences.val ->
          fun curr next _ k ->
            let d = if d then "to" else "downto" in
            [: `BEbox
                  [: `HOVbox
                        [: `S LR "for"; `S LR i; `S LR "=";
                           `expr e1 [: `S LR d :];
                           `expr e2 [: `S LR "do" :] :];
                     `HVbox
                        [: `HVbox [: :];
                           list (fun e k -> expr e [: `S RO ";"; k :]) el
                             [: :] :];
                     `HVbox [: `S LR "done"; k :] :] :]
      | <:expr< for $i$ = $e1$ $to:d$ $e2$ do { $list:el$ } >> ->
          fun curr next _ k ->
            let d = if d then "to" else "downto" in
            [: `sequence
                  [: `HOVbox
                        [: `S LR "for"; `S LR i; `S LR "=";
                           `expr e1 [: `S LR d :]; `expr e2 [: :] :] :]
                  [: :] [: :] el k :]
      | <:expr< while $e1$ do { $list:el$ } >> when old_sequences.val ->
          fun curr next _ k ->
            [: `BEbox
                  [: `BEbox [: `S LR "while"; `expr e1 [: :]; `S LR "do" :];
                     `HVbox
                        [: `HVbox [: :];
                           list (fun e k -> expr e [: `S RO ";"; k :]) el
                             [: :] :];
                     `HVbox [: `S LR "done"; k :] :] :]
      | <:expr< while $e1$ do { $list:el$ } >> ->
          fun curr next _ k ->
            [: `sequence [: `S LR "while"; `expr e1 [: :] :] [: :] [: :] el
                  k :]
      | e -> fun curr next _ k -> [: `next e "" k :] ]};
   {pr_label = ""; pr_box _ x = HOVbox x;
    pr_rules =
      extfun Extfun.empty with
      [ <:expr< $x$ := $y$ >> ->
          fun curr next _ k -> [: `next x "" [: `S LR ":=" :]; `expr y k :]
      | e -> fun curr next _ k -> [: `next e "" k :] ]};
   {pr_label = ""; pr_box _ x = HOVbox [: `HVbox [: :]; x :];
    pr_rules =
      extfun Extfun.empty with
      [ <:expr< $lid:"||"$ $x$ $y$ >> ->
          fun curr next _ k -> [: `next x "" [: `S LR "||" :]; curr y "" k :]
      | <:expr< $lid:"or"$ $x$ $y$ >> ->
          fun curr next _ k -> [: `next x "" [: `S LR "||" :]; curr y "" k :]
      | e -> fun curr next _ k -> [: `next e "" k :] ]};
   {pr_label = ""; pr_box _ x = HOVbox [: `HVbox [: :]; x :];
    pr_rules =
      extfun Extfun.empty with
      [ <:expr< $lid:"&&"$ $x$ $y$ >> ->
          fun curr next _ k -> [: `next x "" [: `S LR "&&" :]; curr y "" k :]
      | <:expr< $lid:"&"$ $x$ $y$ >> ->
          fun curr next _ k -> [: `next x "" [: `S LR "&&" :]; curr y "" k :]
      | e -> fun curr next _ k -> [: `next e "" k :] ]};
   {pr_label = ""; pr_box _ x = HOVbox x;
    pr_rules =
      extfun Extfun.empty with
      [ <:expr< $lid:op$ $x$ $y$ >> as e ->
          fun curr next _ k ->
            match op with
            [ "<" | ">" | "<=" | ">=" | ">=." | "=" | "<>" | "==" | "!=" ->
                [: curr x "" [: `S LR op :]; `next y "" k :]
            | _ -> [: `next e "" k :] ]
      | e -> fun curr next _ k -> [: `next e "" k :] ]};
   {pr_label = ""; pr_box _ x = HOVbox x;
    pr_rules =
      extfun Extfun.empty with
      [ <:expr< $lid:op$ $x$ $y$ >> as e ->
          fun curr next _ k ->
            match op with
            [ "^" | "@" -> [: `next x "" [: `S LR op :]; curr y "" k :]
            | _ -> [: `next e "" k :] ]
      | e -> fun curr next _ k -> [: `next e "" k :] ]};
   {pr_label = ""; pr_box _ x = HOVbox x;
    pr_rules =
      extfun Extfun.empty with
      [ <:expr< $lid:op$ $x$ $y$ >> as e ->
          fun curr next _ k ->
            match op with
            [ "+" | "+." | "-" | "-." ->
                [: curr x "" [: `S LR op :]; `next y "" k :]
            | _ -> [: `next e "" k :] ]
      | e -> fun curr next _ k -> [: `next e "" k :] ]};
   {pr_label = ""; pr_box _ x = HOVbox x;
    pr_rules =
      extfun Extfun.empty with
      [ <:expr< $lid:op$ $x$ $y$ >> as e ->
          fun curr next _ k ->
            match op with
            [ "*" | "/" | "*." | "/." | "land" | "lor" | "lxor" | "mod" ->
                [: curr x "" [: `S LR op :]; `next y "" k :]
            | _ -> [: `next e "" k :] ]
      | e -> fun curr next _ k -> [: `next e "" k :] ]};
   {pr_label = ""; pr_box _ x = HOVbox x;
    pr_rules =
      extfun Extfun.empty with
      [ <:expr< $lid:op$ $x$ $y$ >> as e ->
          fun curr next _ k ->
            match op with
            [ "**" | "asr" | "lsl" | "lsr" ->
                [: `next x "" [: `S LR op :]; curr y "" k :]
            | _ -> [: `next e "" k :] ]
      | e -> fun curr next _ k -> [: `next e "" k :] ]};
   {pr_label = ""; pr_box _ x = HOVbox x;
    pr_rules =
      extfun Extfun.empty with
      [ <:expr< $lid:"~-"$ $x$ >> ->
          fun curr next _ k -> [: `S LR "-"; curr x "" k :]
      | <:expr< $lid:"~-."$ $x$ >> ->
          fun curr next _ k -> [: `S LR "-."; curr x "" k :]
      | e -> fun curr next _ k -> [: `next e "" k :] ]};
   {pr_label = ""; pr_box _ x = HOVbox x;
    pr_rules =
      extfun Extfun.empty with
      [ <:expr< $int:x$ >> -> fun curr next _ k -> [: `S LR x; k :]
      | MLast.ExInt32 _ x -> fun curr next _ k -> [: `S LR (x^"l"); k :]
      | MLast.ExInt64 _ x -> fun curr next _ k -> [: `S LR (x^"L"); k :]
      | MLast.ExNativeInt _ x -> fun curr next _ k -> [: `S LR (x^"n"); k :]
      | e -> fun curr next _ k -> [: `next e "" k :] ]};
   {pr_label = "apply"; pr_box _ x = HOVbox x;
    pr_rules =
      extfun Extfun.empty with
      [ <:expr< [$_$ :: $_$] >> as e ->
          fun curr next _ k -> [: `next e "" k :]
      | <:expr< lazy ($x$) >> ->
          fun curr next _ k -> [: `S LR "lazy"; `next x "" k :]
      | <:expr< assert False >> ->
          fun curr next _ k -> [: `S LR "assert"; `S LR "False"; k :]
      | <:expr< assert ($e$) >> ->
          fun curr next _ k -> [: `S LR "assert"; `next e "" k :]
      | <:expr< $lid:n$ $x$ $y$ >> as e ->
          fun curr next _ k ->
            if is_infix n then [: `next e "" k :]
            else [: curr <:expr< $lid:n$ $x$ >> "" [: :]; `next y "" k :]
      | <:expr< $x$ $y$ >> ->
          if constructors_are_curried() || (not(data_constructor_app x)) then
            fun curr next _ k -> [: curr x "" [: :]; `next y "" k :]
          else
            match uncurry_expr x y with
            [ (f, ( [_;_::_] as args )) ->
                fun curr next _ k ->
                  [: curr f "" [: :];
                     `HOVCbox
                        [: `S LO "(";
                           listws expr (S RO ",") args [: `S RO ")"; k :] :] :]
            | (f, [ arg ]) ->
                fun curr next _ k -> [: curr f "" [: :]; `next arg "" k :]
            | (f, []) -> failwith "patt@pr_r" ]
      | <:expr< new $list:sl$ >> ->
          fun curr next _ k -> [: `S LR "new"; `class_longident sl k :]
      | e -> fun curr next _ k -> [: `next e "" k :] ]};
   {pr_label = "dot"; pr_box _ x = HOVbox x;
    pr_rules =
      extfun Extfun.empty with
      [ <:expr< $x$ . ( $y$ ) >> ->
          fun curr next _ k ->
            [: curr x "" [: :]; `S NO ".("; `expr y [: `S RO ")"; k :] :]
      | <:expr< $x$ . [ $y$ ] >> ->
          fun curr next _ k ->
            [: curr x "" [: :]; `S NO ".["; `expr y [: `S RO "]"; k :] :]
      | <:expr< $e1$ . $e2$ >> ->
          fun curr next _ k -> [: curr e1 "" [: :]; `S NO "."; curr e2 "" k :]
      | <:expr< $e$ # $lab$ >> ->
          fun curr next _ k -> [: curr e "" [: :]; `S NO "#"; `label lab; k :]
      | e -> fun curr next _ k -> [: `next e "" k :] ]};
   {pr_label = "simple";
    pr_box e x = LocInfo (intloc(MLast.loc_of_expr e)) (HOVbox x);
    pr_rules =
      extfun Extfun.empty with
      [ ( <:expr< $int:x$ >> | <:expr< $flo:x$ >> ) ->
          fun curr next _ k ->
            if x.[0] = '-' then [: `S LO "("; `S LR x; `S RO ")"; k :]
            else [: `S LR x; k :]
      | MLast. ExInt32 _ x ->
          fun curr next _ k ->
            let x = x^"l" in
            if x.[0] = '-' then [: `S LO "("; `S LR x; `S RO ")"; k :]
            else [: `S LR x; k :]
      | MLast.ExInt64 _ x ->
          fun curr next _ k ->
            let x = x^"L" in
            if x.[0] = '-' then [: `S LO "("; `S LR x; `S RO ")"; k :]
            else [: `S LR x; k :]
      | MLast.ExNativeInt _ x ->
          fun curr next _ k ->
            let x = x^"n" in
            if x.[0] = '-' then [: `S LO "("; `S LR x; `S RO ")"; k :]
            else [: `S LR x; k :]
      | <:expr< $str:s$ >> ->
          fun curr next _ k -> [: `S LR ("\"" ^ s ^ "\""); k :]
      | <:expr< $chr:c$ >> ->
          fun curr next _ k -> [: `S LR ("'" ^ c ^ "'"); k :]
      | <:expr< $uid:s$ >> -> fun curr next _ k -> [: `S LR s; k :]
      | <:expr< $lid:s$ >> ->
          fun curr next _ k -> [: `S LR (var_escaped s); k :]
      | <:expr< ` $i$ >> -> fun curr next _ k -> [: `S LR ("`" ^ i); k :]
      | <:expr< ~ $i$ >> ->
          fun curr next _ k -> [: `S LR ("~" ^ i); k :]
      | <:expr< ~ $i$ : $e$ >> ->
          fun curr next _ k -> [: `S LO ("~" ^ i ^ ":"); curr e "" k :]
      | <:expr< ? $i$ >> ->
          fun curr next _ k -> [: `S LR ("?" ^ i); k :]
      | <:expr< ? $i$ : $e$ >> ->
          fun curr next _ k -> [: `S LO ("?" ^ i ^ ":"); curr e "" k :]
      | <:expr< [$_$ :: $_$] >> as e ->
          fun curr next _ k ->
            let (el, c) =
              make_list e where rec make_list e =
                match e with
                [ <:expr< [$e$ :: $y$] >> ->
                    let (el, c) = make_list y in
                    ([e :: el], c)
                | <:expr< [] >> -> ([], None)
                | x -> ([], Some e) ]
            in
            match c with
            [ None ->
                [: `S LO "["; listws expr (S RO ";") el [: `S RO "]"; k :] :]
            | Some x ->
                [: `S LO "["; listws expr (S RO ";") el [: `S LR "::" :];
                   `expr x [: `S RO "]"; k :] :] ]
      | <:expr< [| $list:el$ |] >> ->
          fun curr next _ k ->
            [: `S LR "[|"; listws expr (S RO ";") el [: `S LR "|]"; k :] :]
      | <:expr< { $list:fel$ } >> ->
          fun curr next _ k ->
            [: `S LO "{";
               listws
                 (fun (lab, e) k ->
                    HVbox [: let_binding0 [: `patt lab [: :] :] e k :])
                 (S RO ";") fel [: `S RO "}"; k :] :]
      | <:expr< { ($e$) with $list:fel$ } >> ->
          fun curr next _ k ->
            [: `HVbox
                  [: `S LO "{"; `S LO "(";
                     `expr e [: `S RO ")"; `S LR "with" :] :];
               listws
                 (fun (lab, e) k ->
                    HVbox [: `patt lab [: `S LR "=" :]; `expr e k :])
                 (S RO ";") fel [: `S RO "}"; k :] :]
      | <:expr< ($e$ : $t$) >> ->
          fun curr next _ k ->
            [: `S LO "("; `expr e [: `S LR ":" :];
               `ctyp t [: `S RO ")"; k :] :]
      | <:expr< ($e$ : $t1$ :> $t2$) >> ->
          fun curr next _ k ->
            [: `S LO "("; `expr e [: `S LR ":" :]; `ctyp t1 [: `S LR ":>" :];
               `ctyp t2 [: `S RO ")"; k :] :]
      | <:expr< ($e$ :> $t2$) >> ->
          fun curr next _ k ->
            [: `S LO "("; `expr e [: `S LR ":>" :];
               `ctyp t2 [: `S RO ")"; k :] :]
      | <:expr< {< >} >> -> fun curr next _ k -> [: `S LR "{< >}"; k :]
      | <:expr< {< $list:fel$ >} >> ->
          fun curr next _ k ->
            [: `S LR "{<";
               listws field_expr (S RO ";") fel [: `S LR ">}"; k :] :]
      | <:expr< ($list:el$) >> ->
          fun curr next _ k ->
            [: `S LO "("; listws expr (S RO ",") el [: `S RO ")"; k :] :]
      | <:expr< $_$ $_$ >> | <:expr< $_$ . $_$ >> | <:expr< $_$ . ( $_$ ) >> |
        <:expr< $_$ . [ $_$ ] >> | <:expr< $_$ := $_$ >> |
        <:expr< $_$ # $_$ >> |
        <:expr< fun [ $list:_$ ] >> | <:expr< match $_$ with [ $list:_$ ] >> |
        <:expr< try $_$ with [ $list:_$ ] >> |
        <:expr< if $_$ then $_$ else $_$ >> | <:expr< do { $list:_$ } >> |
        <:expr< for $_$ = $_$ $to:_$ $_$ do { $list:_$ } >> |
        <:expr< while $_$ do { $list:_$ } >> |
        <:expr< let $opt:_$ $list:_$ in $_$ >> |
        <:expr< let module $_$ = $_$ in $_$ >> |
        <:expr< new $list:_$ >> as e ->
          fun curr next _ k ->
            [: `S LO "("; `expr e [: `HVbox [: `S RO ")"; k :] :] :]
      | e -> fun curr next _ k -> [: `not_impl "expr" e :] ]}];

pr_patt.pr_levels :=
  [{pr_label = "top";
    pr_box p x = LocInfo (intloc(MLast.loc_of_patt p)) (HOVbox [: `HVbox [: :]; x :]);
    pr_rules =
      extfun Extfun.empty with
      [ <:patt< $x$ | $y$ >> ->
          fun curr next _ k -> [: curr x "" [: `S LR "|" :]; `next y "" k :]
      | p -> fun curr next _ k -> [: `next p "" k :] ]};
   {pr_label = ""; pr_box _ x = HOVbox [: `HVbox [: :]; x :];
    pr_rules =
      extfun Extfun.empty with
      [ <:patt< $x$ .. $y$ >> ->
          fun curr next _ k -> [: curr x "" [: `S NO ".." :]; `next y "" k :]
      | p -> fun curr next _ k -> [: `next p "" k :] ]};
   {pr_label = ""; pr_box _ x = HOVbox x;
    pr_rules =
      extfun Extfun.empty with
      [ <:patt< [$_$ :: $_$] >> as p ->
          fun curr next _ k -> [: `next p "" k :]
      | <:patt< $x$ $y$ >> ->
          if constructors_are_curried() then
            fun curr next _ k -> [: curr x "" [: :]; `next y "" k :]
          else
            match uncurry_patt x y with
            [ (constr, ( [_;_::_] as args )) ->
                fun curr next _ k -> 
                  [: curr constr "" [: :];
                     `HOVCbox
                        [: `S LO "(";
                           listws patt (S RO ",") args [: `S RO ")"; k :] :] :]
            | (constr, [ arg ]) ->
                fun curr next _ k -> [: curr constr "" [: :]; `next arg "" k :]
            | (constr, []) -> failwith "patt@pr_r" ]
      | p -> fun curr next _ k -> [: `next p "" k :] ]};
   {pr_label = ""; pr_box _ x = HOVbox x;
    pr_rules =
      extfun Extfun.empty with
      [ <:patt< $x$ . $y$ >> ->
          fun curr next _ k -> [: curr x "" [: `S NO "." :]; `next y "" k :]
      | p -> fun curr next _ k -> [: `next p "" k :] ]};
   {pr_label = "simple";
    pr_box p x = LocInfo (intloc(MLast.loc_of_patt p)) (HOVbox x);
    pr_rules =
      extfun Extfun.empty with
      [ <:patt< [$_$ :: $_$] >> as p ->
          fun curr next _ k ->
            let (pl, c) =
              make_list p where rec make_list p =
                match p with
                [ <:patt< [$p$ :: $y$] >> ->
                    let (pl, c) = make_list y in
                    ([p :: pl], c)
                | <:patt< [] >> -> ([], None)
                | x -> ([], Some p) ]
            in
            [: `HOVCbox
                  [: `S LO "[";
                     let rec glop pl k =
                       match pl with
                       [ [] -> failwith "simple_patt"
                       | [p] ->
                           match c with
                           [ None -> [: `patt p k :]
                           | Some x ->
                               [: `patt p [: `S LR "::" :]; `patt x k :] ]
                       | [p :: pl] ->
                           [: `patt p [: `S RO ";" :]; glop pl k :] ]
                     in
                     glop pl [: `S RO "]"; k :] :] :]
      | <:patt< [| $list:pl$ |] >> ->
          fun curr next _ k ->
            [: `S LR "[|"; listws patt (S RO ";") pl [: `S LR "|]"; k :] :]
      | <:patt< { $list:fpl$ } >> ->
          fun curr next _ k ->
            [: `HVbox
                  [: `S LO "{";
                     listws
                       (fun (lab, p) k ->
                          HVbox [: `patt lab [: `S LR "=" :]; `patt p k :])
                       (S RO ";") fpl [: `S RO "}"; k :] :] :]
      | <:patt< ($list:[p::pl]$) >> ->
          fun curr next _ k ->
            [: `HOVCbox
                  [: `S LO "(";
                     listws patt (S RO ",") [p :: pl] [: `S RO ")"; k :] :] :]
      | <:patt< ($p$ : $ct$) >> ->
          fun curr next _ k ->
            [: `S LO "("; `patt p [: `S LR ":" :];
               `ctyp ct [: `S RO ")"; k :] :]
      | <:patt< ($x$ as $y$) >> ->
          fun curr next _ k ->
            [: `S LO "("; `patt x [: `S LR "as" :];
               `patt y [: `S RO ")"; k :] :]
      | ( <:patt< $int:s$ >> | <:patt< $flo:s$ >> ) ->
          fun curr next _ k -> [: `S LR s; k :]
      | MLast.PaInt32 _ s -> fun curr next _ k -> [: `S LR (s^"l"); k :]
      | MLast.PaInt64 _ s -> fun curr next _ k -> [: `S LR (s^"L"); k :]
      | MLast.PaNativeInt _ s -> fun curr next _ k -> [: `S LR (s^"n"); k :]
      | <:patt< $str:s$ >> ->
          fun curr next _ k -> [: `S LR ("\"" ^ s ^ "\""); k :]
      | <:patt< $chr:c$ >> ->
          fun curr next _ k -> [: `S LR ("'" ^ c ^ "'"); k :]
      | <:patt< $lid:s$ >> ->
          fun curr next _ k -> [: `S LR (var_escaped s); k :]
      | <:patt< $uid:s$ >> -> fun curr next _ k -> [: `S LR s; k :]
      | <:patt< ` $i$ >> -> fun curr next _ k -> [: `S LR ("`" ^ i); k :]
      | <:patt< # $list:sl$ >> ->
          fun curr next _ k -> [: `S LO "#"; mod_ident sl k :]
      | <:patt< ~ $i$ >> ->
          fun curr next _ k -> [: `S LR ("~" ^ i); k :]
      | <:patt< ~ $i$ : $p$ >> ->
          fun curr next _ k -> [: `S LO ("~" ^ i ^ ":"); curr p "" k :]
      | <:patt< ? $i$ >> ->
          fun curr next _ k -> [: `S LR ("?" ^ i); k :]
      | <:patt< ? $i$ : ($p$ : $t$) >> ->
          fun curr next _ k ->
            [: `S LO ("?" ^ i ^ ":"); `S LO "("; `patt p [: `S LR ":" :];
               `ctyp t [: `S RO ")"; k :] :]
      | <:patt< ? $i$ : ($p$) >> ->
          fun curr next _ k ->
            if i = "" then [: `S LO "?"; curr p "" k :]
            else
              [: `S LO ("?" ^ i ^ ":"); `S LO "(";
                 `patt p [: `S RO ")"; k :] :]
      | <:patt< ? $i$ : ($p$ : $t$ = $e$) >> ->
          fun curr next _ k ->
            if i = "" then
              [: `S LO "?"; `S LO "("; `patt p [: `S LR ":" :];
                 `ctyp t [: `S LR "=" :]; `expr e [: `S RO ")"; k :] :]
            else
              [: `S LO ("?" ^ i ^ ":"); `S LO "("; `patt p [: `S LR ":" :];
                 `ctyp t [: `S LR "=" :]; `expr e [: `S RO ")"; k :] :]
      | <:patt< ? $i$ : ($p$ = $e$) >> ->
          fun curr next _ k ->
            if i = "" then
              [: `S LO "?"; `S LO "("; `patt p [: `S LR "=" :];
                 `expr e [: `S RO ")"; k :] :]
            else
              [: `S LO ("?" ^ i ^ ":"); `S LO "("; `patt p [: `S LR "=" :];
                 `expr e [: `S RO ")"; k :] :]
      | <:patt< _ >> -> fun curr next _ k -> [: `S LR "_"; k :]
      | <:patt< $_$ $_$ >> | <:patt< $_$ .. $_$ >> |
        <:patt< $_$ | $_$ >> as p ->
          fun curr next _ k ->
            [: `S LO "("; `patt p [: `HVbox [: `S RO ")"; k :] :] :]
      | p -> fun curr next _ k -> [: `next p "" k :] ]}];

pr_ctyp.pr_levels :=
  [{pr_label = "top"; pr_box t x = LocInfo (intloc(MLast.loc_of_ctyp t)) (HOVbox x);
    pr_rules =
      extfun Extfun.empty with
      [ <:ctyp< $t1$ == $t2$ >> ->
          fun curr next _ k ->
            [: curr t1 "" [: `S LR "==" :]; `next t2 "" k :]
      | t -> fun curr next _ k -> [: `next t "" k :] ]};
   {pr_label = ""; pr_box _ x = HOVbox x;
    pr_rules =
      extfun Extfun.empty with
      [ <:ctyp< $x$ as $y$ >> ->
          fun curr next _ k -> [: curr x "" [: `S LR "as" :]; `next y "" k :]
      | t -> fun curr next _ k -> [: `next t "" k :] ]};
   {pr_label = ""; pr_box _ x = HOVbox x;
    pr_rules =
      extfun Extfun.empty with
      [ <:ctyp< ! $list:pl$ . $t$ >> ->
          fun curr next dg k ->
            if pl = [] then [: `ctyp t k :]
            else
              [: `HVbox [: `S LR "!"; list typevar pl [: `S LR "." :] :];
                 `ctyp t k :]
      | t -> fun curr next _ k -> [: `next t "" k :] ]};
   {pr_label = ""; pr_box _ x = HOVbox x;
    pr_rules =
      extfun Extfun.empty with
      [ <:ctyp< $x$ -> $y$ >> ->
          fun curr next _ k -> [: `next x "" [: `S LR "->" :]; curr y "" k :]
      | t -> fun curr next _ k -> [: `next t "" k :] ]};
   {pr_label = ""; pr_box _ x = HOVbox x;
    pr_rules =
      extfun Extfun.empty with
      [ <:ctyp< $t1$ $t2$ >> ->
          fun curr next _ k -> [: curr t1 "" [: :]; `next t2 "" k :]
      | t -> fun curr next _ k -> [: `next t "" k :] ]};
   {pr_label = ""; pr_box _ x = HOVbox x;
    pr_rules =
      extfun Extfun.empty with
      [ <:ctyp< ? $lab$ : $t$ >> ->
          fun curr next _ k ->
            [: `S LO "?"; `S LR lab; `S RO ":"; `next t "" k :]
      | <:ctyp< ~ $lab$ : $t$ >> ->
          fun curr next _ k -> [: `S LO ("~" ^ lab ^ ":"); `next t "" k :]
      | t -> fun curr next _ k -> [: `next t "" k :] ]};
   {pr_label = ""; pr_box _ x = HOVbox x;
    pr_rules =
      extfun Extfun.empty with
      [ <:ctyp< $t1$ . $t2$ >> ->
          fun curr next _ k ->
            [: curr t1 "" [: :]; `S NO "."; `next t2 "" k :]
      | t -> fun curr next _ k -> [: `next t "" k :] ]};
   {pr_label = "simple";
    pr_box t x = LocInfo (intloc(MLast.loc_of_ctyp t)) (HOVbox x);
    pr_rules =
      extfun Extfun.empty with
      [ <:ctyp< ($list:tl$) >> ->
          fun curr next _ k ->
            [: `S LO "("; listws ctyp (S LR "*") tl [: `S RO ")"; k :] :]
      | <:ctyp< '$s$ >> ->
          fun curr next _ k -> [: `S LO "'"; `S LR (var_escaped s); k :]
      | <:ctyp< $lid:s$ >> ->
          fun curr next _ k -> [: `S LR (var_escaped s); k :]
      | <:ctyp< $uid:s$ >> -> fun curr next _ k -> [: `S LR s; k :]
      | <:ctyp< _ >> -> fun curr next _ k -> [: `S LR "_"; k :]
      | <:ctyp< private $ty$ >> ->
          fun curr next dg k ->
            [: `HVbox
               [: `HVbox [:`S LR "private" :];
                  `ctyp ty k :] :]
      | <:ctyp< { $list: ftl$ } >> as t ->
          fun curr next _ k ->
            let loc = MLast.loc_of_ctyp t in
            [: `HVbox
                  [: labels loc [: `S LR "{" :] ftl [: `S LR "}" :]; k :] :]
      | <:ctyp< [ $list:ctl$ ] >> as t ->
          fun curr next _ k ->
            let loc = MLast.loc_of_ctyp t in
            [: `Vbox
                  [: `HVbox [: :];
                     variants loc [: `S LR "[" :] ctl [: `S LR "]" :]; k :] :]
      | <:ctyp< [ = $list:rfl$ ] >> ->
          fun curr next _ k ->
            [: `HVbox
                  [: `HVbox [: :];
                     row_fields [: `S LR "[ =" :] rfl [: `S LR "]" :]; k :] :]
      | <:ctyp< [ > $list:rfl$ ] >> ->
          fun curr next _ k ->
            [: `HVbox
                  [: `HVbox [: :];
                     row_fields [: `S LR "[ >" :] rfl [: `S LR "]" :]; k :] :]
      | <:ctyp< [ < $list:rfl$ > $list:sl$ ] >> ->
          fun curr next _ k ->
            let k1 = [: `S LR "]" :] in
            let k1 =
              match sl with
              [ [] -> k1
              | l ->
                  [: `S LR ">";
                     list (fun x k -> HVbox [: `S LR x; k :]) l k1 :] ]
            in
            [: `HVbox
                  [: `HVbox [: :]; row_fields [: `S LR "[ <" :] rfl k1;
                     k :] :]
      | <:ctyp< # $list:id$ >> ->
          fun curr next _ k -> [: `S LO "#"; `class_longident id k :]
      | <:ctyp< < > >> -> fun curr next _ k -> [: `S LR "<>"; k :]
      | <:ctyp< < $list:ml$ $opt:v$ > >> ->
          fun curr next _ k ->
            [: `S LR "<"; meth_list (ml, v) [: `S LR ">"; k :] :]
      | <:ctyp< $_$ -> $_$ >> | <:ctyp< $_$ $_$ >> | <:ctyp< $_$ == $_$ >> |
        <:ctyp< $_$ . $_$ >> | <:ctyp< $_$ as $_$ >> |
        <:ctyp< ? $_$ : $_$ >> | <:ctyp< ~ $_$ : $_$ >> |
        <:ctyp< ! $list:_$ . $_$ >> as t ->
          fun curr next _ k ->
            [: `S LO "("; `ctyp t [: `HVbox [: `S RO ")"; k :] :] :]
      | t -> fun curr next _ k -> [: `next t "" k :] ]}];

pr_class_sig_item.pr_levels :=
  [{pr_label = "top";
    pr_box s x = LocInfo (intloc(MLast.loc_of_class_sig_item s)) (HVbox x);
    pr_rules =
      extfun Extfun.empty with
      [ <:class_sig_item< type $t1$ = $t2$ >> ->
          fun curr next _ k ->
            [: `S LR "type"; `ctyp t1 [: `S LR "=" :]; `ctyp t2 k :]
      | <:class_sig_item< declare $list:s$ end >> ->
          fun curr next _ k -> [: `HVbox [: :]; list class_sig_item s k :]
      | <:class_sig_item< inherit $ce$ >> ->
          fun curr next _ k -> [: `S LR "inherit"; `class_type ce k :]
      | <:class_sig_item< method $lab$ : $t$ >> ->
          fun curr next _ k ->
            [: `HVbox
                  [: `S LR "method"; `label lab; `S LR ":" :];
               `ctyp t k :]
      | <:class_sig_item< method private $lab$ : $t$ >> ->
          fun curr next _ k ->
            [: `HVbox
                  [: `S LR "method"; `S LR "private"; `label lab;
                     `S LR ":" :];
               `ctyp t k :]
      | <:class_sig_item< value $opt:mf$ $lab$ : $t$ >> ->
          fun curr next _ k ->
            [: `HVbox
                  [: `S LR "value"; flag "mutable" mf; `label lab;
                     `S LR ":" :];
               `ctyp t k :]
      | <:class_sig_item< method virtual $lab$ : $t$ >> ->
          fun curr next _ k ->
            [: `HVbox
                  [: `S LR "method"; `S LR "virtual"; `label lab;
                     `S LR ":" :];
               `ctyp t k :]
      | <:class_sig_item< method virtual private $lab$ : $t$ >> ->
          fun curr next _ k ->
            [: `HVbox
                  [: `S LR "method"; `S LR "virtual"; `S LR "private";
                     `label lab; `S LR ":" :];
               `ctyp t k :]
      | csi -> fun curr next dg k -> [: `next csi "" k :] ]}];

pr_class_str_item.pr_levels :=
  [{pr_label = "top";
    pr_box s x = LocInfo (intloc(MLast.loc_of_class_str_item s)) (HVbox x);
    pr_rules =
      extfun Extfun.empty with
      [ MLast.CrDcl _ s ->
          fun curr next _ k -> [: `HVbox [: :]; list class_str_item s [: :] :]
      | MLast.CrInh _ ce pb ->
          fun curr next _ k ->
            [: `S LR "inherit"; `class_expr ce [: :];
               match pb with
               [ Some i -> [: `S LR "as"; `S LR i :]
               | _ -> [: :] ];
               k :]
      | MLast.CrVal _ lab mf e ->
          fun curr next _ k ->
            [: `cvalue [: `S LR "value" :] (lab, mf, e) k :]
      | MLast.CrVir _ lab pf t ->
          fun curr next _ k ->
            [: `S LR "method"; `S LR "virtual"; flag "private" pf; `label lab;
               `S LR ":"; `ctyp t k :]
      | MLast.CrMth _ lab pf fb None ->
          fun curr next _ k ->
            [: `fun_binding
                  [: `S LR "method"; flag "private" pf; `label lab :] fb k :]
      | MLast.CrMth _ lab pf fb (Some t) ->
          fun curr next dg k ->
            [: `HOVbox
                  [: `S LR "method"; flag "private" pf; `label lab; `S LR ":";
                     `ctyp t [: `S LR "=" :] :];
               `expr fb k :]
      | MLast.CrCtr _ t1 t2 ->
          fun curr next _ k ->
            [: `HVbox [: `S LR "type"; `ctyp t1 [: `S LR "=" :] :];
               `ctyp t2 k :]
      | MLast.CrIni _ se ->
          fun curr next _ k -> [: `S LR "initializer"; `expr se k :]
      | csi -> fun curr next dg k -> [: `next csi "" k :] ]}];

pr_class_type.pr_levels :=
  [{pr_label = "top"; pr_box s x = HVbox x;
    pr_rules =
      extfun Extfun.empty with
      [ MLast.CtFun _ t ct ->
          fun curr next _ k ->
            [: `S LR "["; `ctyp t [: `S LR "]"; `S LR "->" :];
               `class_type ct k :]
      | ct -> fun curr next _ k -> [: `class_signature ct k :] ]}];

pr_class_expr.pr_levels :=
  [{pr_label = "top"; pr_box s x = HVbox x;
    pr_rules =
      extfun Extfun.empty with
      [ MLast.CeFun _ p ce ->
          fun curr next _ k ->
            [: `S LR "fun"; `simple_patt p [: `S LR "->" :];
               `class_expr ce k :]
      | MLast.CeLet _ rf lb ce ->
          fun curr next _ k ->
            [: `Vbox
                  [: `HVbox [: :];
                     `bind_list [: `S LR "let"; flag "rec" rf :] lb
                        [: `S LR "in" :];
                     `class_expr ce k :] :]
      | x -> fun curr next dg k -> [: `next x "" k :] ]};
   {pr_label = ""; pr_box s x = HVbox x;
    pr_rules =
      extfun Extfun.empty with
      [ MLast.CeApp _ ce e ->
          fun curr next _ k -> [: curr ce "" [: :]; `simple_expr e k :]
      | x -> fun curr next dg k -> [: `next x "" k :] ]};
   {pr_label = ""; pr_box s x = HVbox x;
    pr_rules =
      extfun Extfun.empty with
      [ MLast.CeCon _ ci [] ->
          fun curr next _ k -> [: `class_longident ci k :]
      | MLast.CeCon _ ci ctcl ->
          fun curr next _ k ->
            [: `class_longident ci [: :]; `S LO "[";
               listws ctyp (S RO ",") ctcl [: `S RO "]"; k :] :]
      | MLast.CeStr _ csp cf as ce ->
          fun curr next _ k ->
            let ep = snd (MLast.loc_of_class_expr ce) in
            [: `BEbox
                  [: `HVbox [: `S LR "object"; `class_self_patt_opt csp :];
                     `HVbox
                        [: `HVbox [: :]; list class_str_item cf [: :];
                           `LocInfo (intloc(ep, ep)) (HVbox [: :]) :];
                     `HVbox [: `S LR "end"; k :] :] :]
      | MLast.CeTyc _ ce ct ->
          fun curr next _ k ->
            [: `S LO "("; `class_expr ce [: `S LR ":" :];
               `class_type ct [: `S RO ")"; k :] :]
      | MLast.CeFun _ _ _ as ce ->
          fun curr next _ k ->
            [: `S LO "("; `class_expr ce [: `S RO ")"; k :] :]
      | ce -> fun curr next _ k -> [: `not_impl "class_expr" ce; k :] ]}];

value output_string_eval oc s =
  loop 0 where rec loop i =
    if i == String.length s then ()
    else if i == String.length s - 1 then output_char oc s.[i]
    else
      match (s.[i], s.[i + 1]) with
      [ ('\\', 'n') -> do { output_char oc '\n'; loop (i + 2) }
      | (c, _) -> do { output_char oc c; loop (i + 1) } ]
;

value maxl = ref 78;
value sep = Pcaml.inter_phrases;
value ncip = ref True;

value input_source ic len =
  let buff = Buffer.create 20 in
  try
    let rec loop i =
      if i >= len then Buffer.contents buff
      else do { let c = input_char ic in Buffer.add_char buff c; loop (i + 1) }
    in
    loop 0
  with
  [ End_of_file ->
      let s = Buffer.contents buff in
      if s = "" then
        match sep.val with
        [ Some s -> s
        | None -> "\n" ]
      else s ]
;

value copy_source ic oc first bp ep =
  match sep.val with
  [ Some str ->
      if first then ()
      else if ep == in_channel_length ic then output_string oc "\n"
      else output_string_eval oc str
  | None ->
      do {
        seek_in ic bp;
        let s = input_source ic (ep - bp) in
        output_string oc s
      } ]
;

value copy_to_end ic oc first bp =
  let ilen = in_channel_length ic in
  if bp < ilen then copy_source ic oc first bp ilen else output_string oc "\n"
;

module Buff =
  struct
    value buff = ref (String.create 80);
    value store len x =
      do {
        if len >= String.length buff.val then
          buff.val := buff.val ^ String.create (String.length buff.val)
        else ();
        buff.val.[len] := x;
        succ len
      }
    ;
    value mstore len s =
      add_rec len 0 where rec add_rec len i =
        if i == String.length s then len
        else add_rec (store len s.[i]) (succ i)
    ;
    value get len = String.sub buff.val 0 len;
  end
;

value extract_comment strm =
  let rec find_comm nl_bef tab_bef =
    parser
    [ [: `'('; a = find_star nl_bef tab_bef :] -> a
    | [: `' '; s :] -> find_comm nl_bef (tab_bef + 1) s
    | [: `'\t'; s :] -> find_comm nl_bef (tab_bef + 8) s
    | [: `'\n'; s :] -> find_comm (nl_bef + 1) 0 s
    | [: `_; s :] -> find_comm 0 0 s
    | [: :] -> ("", nl_bef, tab_bef) ]
  and find_star nl_bef tab_bef =
    parser
    [ [: `'*'; a = insert (Buff.mstore 0 "(*") :] -> (a, nl_bef, tab_bef)
    | [: a = find_comm 0 0 :] -> a ]
  and insert len =
    parser
    [ [: `'*'; a = rparen (Buff.store len '*') :] -> a
    | [: `'('; len = find_star2 (Buff.store len '('); s :] -> insert len s
    | [: `'\t'; s :] -> insert (Buff.mstore len (String.make 8 ' ')) s
    | [: `x; s :] -> insert (Buff.store len x) s
    | [: :] -> "" ]
  and rparen len =
    parser
    [ [: `')'; s :] -> while_space (Buff.store len ')') s
    | [: a = insert len :] -> a ]
  and while_space len =
    parser
    [ [: `' '; a = while_space (Buff.store len ' ') :] -> a
    | [: `'\t'; a = while_space (Buff.mstore len (String.make 8 ' ')) :] -> a
    | [: `'\n'; a = while_space (Buff.store len '\n') :] -> a
    | [: `'('; a = find_star_again len :] -> a
    | [: :] -> Buff.get len ]
  and find_star_again len =
    parser
    [ [: `'*'; a = insert (Buff.mstore len "(*") :] -> a
    | [: :] -> Buff.get len ]
  and find_star2 len =
    parser
    [ [: `'*'; a = insert2 (Buff.store len '*') :] -> a
    | [: :] -> len ]
  and insert2 len =
    parser
    [ [: `'*'; a = rparen2 (Buff.store len '*') :] -> a
    | [: `'('; len = find_star2 (Buff.store len '('); s :] -> insert2 len s
    | [: `x; s :] -> insert2 (Buff.store len x) s
    | [: :] -> 0 ]
  and rparen2 len =
    parser
    [ [: `')' :] -> Buff.store len ')'
    | [: a = insert2 len :] -> a ]
  in
  find_comm 0 0 strm
;

value get_no_comment _ _ = ("", 0, 0, 0);

value get_comment ic beg len =
  do {
    seek_in ic beg;
    let strm =
      Stream.from (fun i -> if i >= len then None else Some (input_char ic))
    in
    let (s, nl_bef, tab_bef) = extract_comment strm in
    (s, nl_bef, tab_bef, Stream.count strm)
  }
;

value apply_printer printer ast =
  let oc =
    match Pcaml.output_file.val with
    [ Some f -> open_out_bin f
    | None -> stdout ]
  in
  let cleanup () =
    match Pcaml.output_file.val with
    [ Some _ -> close_out oc
    | None -> () ]
  in
  let pr_ch = output_char oc in
  let pr_str = output_string oc in
  let pr_nl () = output_char oc '\n' in
  if Pcaml.input_file.val <> "-" && Pcaml.input_file.val <> "" then do {
    let ic = open_in_bin Pcaml.input_file.val in
    let getcom =
      if not ncip.val && sep.val = None then get_comment ic
      else get_no_comment
    in
    try
      let (first, last_pos) =
        List.fold_left
          (fun (first, last_pos) (si, (bp, ep)) ->
             do {
               copy_source ic oc first last_pos.Lexing.pos_cnum bp.Lexing.pos_cnum;
               flush oc;
               print_pretty pr_ch pr_str pr_nl "" "" maxl.val getcom bp.Lexing.pos_cnum
                 (printer si [: :]);
               flush oc;
               (False, ep)
             })
          (True, Token.nowhere) ast
      in
      do { copy_to_end ic oc first last_pos.Lexing.pos_cnum; flush oc }
    with x ->
      do { close_in ic; cleanup (); raise x };
    close_in ic;
    cleanup ()
  }
  else do {
    List.iter
      (fun (si, _) ->
         do {
           print_pretty pr_ch pr_str pr_nl "" "" maxl.val get_no_comment 0
             (printer si [: :]);
           match sep.val with
           [ Some str -> output_string_eval oc str
           | None -> output_char oc '\n' ];
           flush oc
         })
      ast;
    cleanup ()
  }
;

Pcaml.print_interf.val := apply_printer sig_item;
Pcaml.print_implem.val := apply_printer str_item;

Pcaml.add_option "-l" (Arg.Int (fun x -> maxl.val := x))
  "<length> Maximum line length for pretty printing.";

Pcaml.add_option "-sep_src" (Arg.Unit (fun () -> sep.val := None))
  "Read source file for text between phrases (default).";

Pcaml.add_option "-sep" (Arg.String (fun x -> sep.val := Some x))
  "<string> Use this string between phrases instead of reading source.";

Pcaml.add_option "-no_where" (Arg.Clear gen_where)
  "Dont generate \"where\" statements";

Pcaml.add_option "-cip" (Arg.Clear ncip) "Add comments in phrases.";

Pcaml.add_option "-ncip" (Arg.Set ncip) "No comments in phrases (default).";

Pcaml.add_option "-old_seq" (Arg.Set old_sequences)
  "Pretty print with old syntax for sequences.";

Pcaml.add_option "-exp_dcl" (Arg.Set expand_declare)
  "Expand the \"declare\" items.";

Pcaml.add_option "-tc" (Arg.Clear ncip)
  "Deprecated since version 3.05; equivalent to -cip.";

Pcaml.add_option "-no_curried_constructors" (Arg.Set no_curried_constructors)
  "Considers all non constant data constructors as unary.";