platex.cfg

%%% candidate 3 (rewrite in plexpl3): mostly compatible
\ExplSyntaxOn
%% File: plexpl3.dtx
\cs_if_exist:NT \__platex_expl_loaded:
  {
    \GenericInfo{}
      {Skipping:~ plexpl3~ code~ already~ part~ of~ the~ format}%
    \ExplSyntaxOff  %% platex.cfg specific
    \endinput
  }
\cs_new:Npn \__platex_expl_loaded: {  }
%% additions to l3box.dtx: writing directions (pTeX/upTeX-specific)
\cs_set_eq:NN \platex_direction_yoko: \tex_yoko:D
\cs_set_eq:NN \platex_direction_tate: \tex_tate:D
\cs_set_eq:NN \platex_direction_dtou: \tex_dtou:D
\prg_new_conditional:Npnn \platex_if_direction_yoko: { p, T, F, TF }
  { \tex_ifydir:D \prg_return_true: \else: \prg_return_false: \fi: }
\prg_new_conditional:Npnn \platex_if_direction_tate: { p, T, F, TF }
  { \tex_iftdir:D \prg_return_true: \else: \prg_return_false: \fi: }
\prg_new_conditional:Npnn \platex_if_direction_dtou: { p, T, F, TF }
  { \tex_ifddir:D \prg_return_true: \else: \prg_return_false: \fi: }
\prg_new_conditional:Npnn \platex_if_box_yoko:N #1 { p, T, F, TF }
  { \tex_ifybox:D #1 \prg_return_true: \else: \prg_return_false: \fi: }
\prg_new_conditional:Npnn \platex_if_box_tate:N #1 { p, T, F, TF }
  { \tex_iftbox:D #1 \prg_return_true: \else: \prg_return_false: \fi: }
\prg_new_conditional:Npnn \platex_if_box_dtou:N #1 { p, T, F, TF }
  { \tex_ifdbox:D #1 \prg_return_true: \else: \prg_return_false: \fi: }
%% File: plcore.dtx
\if_cs_exist:N \__shipout_execute_cont:
\cs_new_eq:NN \__platex_original_shipout_execute_cont: \__shipout_execute_cont:
\box_new:N \l__platex_shipout_dummy_box
\cs_set:Npn \__shipout_execute_cont:
  {
    % >>> \l_shipout_box が横組でない場合は事前に横組化する
    % if \l_shipout_box is not a \yoko-box (= horizontal writing),
    % then make it a \yoko-box behorehand.
    \platex_if_box_yoko:NF \l_shipout_box {
      \vbox_set:Nn \l_shipout_box
        {
            \platex_direction_yoko:
            \box_use:N \l_shipout_box
        }
    }
    % >>> 横組でない場合は \__shipout_execute_cont: を
    % >>> 横組ボックス \l__platex_shipout_dummy_box で括って実行する
    % if the current direction is not \yoko,
    % then enclose \__shipout_execute_cont: with
    % a dummy \yoko-box named \l__platex_shipout_dummy_box.
    \platex_if_direction_yoko:TF {
      \__platex_original_shipout_execute_cont:
    }{
      \vbox_set:Nn \l__platex_shipout_dummy_box
        {
          \platex_direction_yoko:
          \__platex_original_shipout_execute_cont:
        }
      % >>> 制限事項：処理終了時に \box\l__platex_shipout_dummy_box して
      % >>> メイン垂直リストに中身を戻したいが，無限ループするので不可。
      % [Limitation] the code above may discard some contents,
      % so we'd like to put it back by \box\l__platex_shipout_dummy_box.
      % however, an infinite loop occurs if we uncomment the line below
      % so we can't.
      %\box_use:N \l__platex_shipout_dummy_box
    }
  }
\fi:
%%
\ExplSyntaxOff
%%%