%%
%% This is file 'ifptex.sty'.
%% 
%% Copyright (c) 2017 Takayuki YATO (aka. "ZR")
%%   GitHub:   https://github.com/zr-tex8r
%%   Twitter:  @zr_tex8r
%%
%% This package is distributed under the MIT License.
%%
%
%% avoid multiple loading
\csname\if11bxipIfptexLoaded\fi\endcsname
%% code guards
\edef\x{%
\catcode32=\the\catcode32%
\catcode33=\the\catcode33%
\catcode35=\the\catcode35%
\catcode42=\the\catcode42%
\catcode60=\the\catcode60%
\catcode62=\the\catcode62%
\catcode64=\the\catcode64%
\catcode91=\the\catcode91%
\catcode93=\the\catcode93%
\relax}
\catcode32=10\relax
\catcode33=11 %<">
\catcode35=6  %<#>
\catcode42=12 %<*>
\catcode60=12 %<<>
\catcode62=12 %<>>
\catcode64=11 %<@>
\catcode91=12 %<[>
\catcode93=12 %<]>
\edef\bxip@restore@codes{\x
  \noexpand\let\noexpand\bxip@restore@codes\relax}
\def\bxipIfptexLoaded{\endinput}

%% check for LaTeX
\ifx\RequirePackage\@undefined %<*!LaTeX>
  \let\bxip@latex=f
  \long\def\x#1\ProvidesPackage#2[#3]{%
    \immediate\write-1{Package: #2 #3}}
  \expandafter\x
\else                          %<*LaTeX>
  \let\bxip@latex=t \let\x\relax
\fi                            %</LaTeX>

%% package declaration
\NeedsTeXFormat{LaTeX2e}
\ProvidesPackage{ifptex}[2017/09/09 v1.2 pTeX checker]

%% enter the big group
\begingroup

%--------------------------------------- helpers

%% \bxip@csletcs{<csnameA>}{<csnameB>}
\def\bxip@csletcs#1#2{%
  \expandafter\let\csname#1\expandafter\endcsname\csname#2\endcsname}
%% \bxip@true{<csname>}
\def\bxip@true#1{%
  \expandafter\let\csname#1\endcsname\iftrue}
%% \bxip@false{<csname>}
\def\bxip@false#1{%
  \expandafter\let\csname#1\endcsname\iffalse}

%% switches
\bxip@false{ifbxip@ok}

%% \bxip@test@primitive\CS
\def\bxip@test@primitive#1{%
  \edef\bxip@tmpa{\string#1}\edef\bxip@tmpb{\meaning#1}%
  \ifx\bxip@tmpa\bxip@tmpb \bxip@true{ifbxip@ok}%
  \else \bxip@false{ifbxip@ok}%
  \fi}

%% \bxip@with@default{<arg>}\CS
\gdef\bxip@with@default#1#2{%
  \def\bxip@tmpa{#2}\def\bxip@tmpb{#2[#1]}%
  \futurelet\bxip@tok\bxip@with@default@a}
\gdef\bxip@with@default@a{%
  \ifx[\bxip@tok\expandafter\bxip@tmpa%]
  \else \expandafter\bxip@tmpb
  \fi}

%% \bxip@check@version{<current>}{<required>}{<label>}
\global\countdef\bxip@cnta=255
\gdef\bxip@check@version#1#2#3{%
  \ifnum#1<#2\relax
    \begingroup
      \bxip@cnta=#2\relax \advance\bxip@cnta100000\relax
      \expandafter\bxip@check@version@a\the\bxip@cnta\relax{#3}%
    \endgroup
  \fi}
\gdef\bxip@check@version@a#1#2#3#4#5#6\relax#7{%
  \bxip@err@required{#7 v.>=\number#2#3#4.#5#6}}

%% \bxip@err@required{<string>}
% NB: Now the same style as in ifxetex is used.
\gdef\bxip@err@required#1{%
  \begingroup
    \errorcontextlines=-1\relax
    \newlinechar=10\relax
    \errmessage{^^J
    ********************************************^^J
    * #1 is required to compile this document.^^J
    * Sorry!^^J
    ********************************************}%
  \endgroup}

%--------------------------------------- guess version

%% \bxip@uptex@new@version
\global\mathchardef\bxip@uptex@new@version=19

%%<+> \upTeXguessedversion
\global\mathchardef\upTeXguessedversion=0
% if \ucs exists, then gv >= 1
\bxip@test@primitive\ucs\ifbxip@ok
  \global\mathchardef\upTeXguessedversion=1
  % if \enablecjktoken exists, then gv >= 6
  \bxip@test@primitive\enablecjktoken\ifbxip@ok
    \global\mathchardef\upTeXguessedversion=6
    % if \kchar exists, then gv >= 10
    \bxip@test@primitive\kchar\ifbxip@ok
      \global\mathchardef\upTeXguessedversion=10
      % if \forcecjktoken exists, then gv >= 19
      \bxip@test@primitive\forcecjktoken\ifbxip@ok
        \global\mathchardef\upTeXguessedversion=19
      \fi
    \fi
  \fi
\fi

%--------------------------------------- public stuffs
% Note:
% 1) Names '\ifFooTeX' are used in iftex.
% 2) Names '\iffootex' are used in ifxetex/ifluatex/....
% My preferences are:
% - '\ifwhateverFooTeX' and '\RequireWhateverFooTeX'.
% But I also provide aliases '\iffootex' and '\ifstrictfootex' for
% compatibility with 1) and the old ifuptex.

%%<+> \ifpTeX
\global\bxip@false{ifpTeX}
\bxip@test@primitive\kanjiskip\ifbxip@ok
  \global\bxip@true{ifpTeX}
\fi
%%<+> \ifptex == \ifpTeX
\global\bxip@csletcs{ifptex}{ifpTeX}

%%<+> \ifupTeX
\global\bxip@false{ifupTeX}
%%<+> \ifnativeupTeX
\global\bxip@false{ifnativeupTeX}
\ifnum\upTeXguessedversion>0
  \global\bxip@true{ifupTeX}
  % native-ness check
  \ifnum\ucs"3000="3000 \global\bxip@true{ifnativeupTeX}\fi
\fi
%%<+> \ifuptex == \ifupTeX
\global\bxip@csletcs{ifuptex}{ifupTeX}

%%<+> \ifpTeXng
\global\bxip@false{ifpTeXng}
\bxip@test@primitive\ngbanner\ifbxip@ok
  \global\bxip@true{ifpTeXng}
\fi
%%<+> \ifptexng == \ifpTeXng
\global\bxip@csletcs{ifptexng}{ifpTeXng}

%%<+> \ifstrictpTeX
\global\bxip@false{ifstrictpTeX}
\ifpTeX \ifupTeX\else
  \global\bxip@true{ifstrictpTeX}
\fi\fi
%%<+> \ifstrictptex == \ifstrictpTeX
\global\bxip@csletcs{ifstrictptex}{ifstrictpTeX}

%%<+> \ifstrictupTeX
\global\bxip@false{ifstrictupTeX}
\ifupTeX \ifpTeXng\else
  \global\bxip@true{ifstrictupTeX}
\fi\fi
%%<+> \ifstrictuptex == \ifstrictupTeX
\global\bxip@csletcs{ifstrictuptex}{ifstrictupTeX}

%%<+> \ifstrictpTeXng (== \ifpTeXng, for now)
\global\bxip@csletcs{ifstrictpTeXng}{ifpTeXng}
%%<+> \ifstrictptexng == \ifstrictpTeXng
\global\bxip@csletcs{ifstrictptexng}{ifstrictpTeXng}

%%<+> \RequirepTeX
\gdef\RequirepTeX{%
  \ifpTeX\else \bxip@err@required{(u)pTeX}\fi}
%%<+> \RequireStrictpTeX
\gdef\RequireStrictpTeX{%
  \ifstrictpTeX\else \bxip@err@required{pTeX (not upTeX)}\fi}
%%<+> \RequireupTeX
\gdef\RequireupTeX{%
  \ifupTeX\else \bxip@err@required{upTeX}\fi}
%%<+> \RequireStrictupTeX
\gdef\RequireStrictupTeX{%
  \ifstrictupTeX\else \bxip@err@required{upTeX (not pTeX-ng)}\fi}
%%<+> \RequireNativeupTeX
\gdef\RequireNativeupTeX{%
  \ifnativeupTeX\else \bxip@err@required{upTeX in Unicode}\fi}
%%<+> \RequirepTeXng
\gdef\RequirepTeXng{%
  \ifpTeXng\else \bxip@err@required{pTeX-ng}\fi}
%%<+> \RequireStrictpTeXng
\gdef\RequireStrictpTeXng{%
  \ifstrictpTeXng\else \bxip@err@required{pTeX-ng}\fi}

%--------------------------------------- deprecated stuffs

%%<+>D \ifNativeupTeX == \ifnativeupTeX
\global\bxip@csletcs{ifNativeupTeX}{ifnativeupTeX}
%%<+>D \RequirenativeupTeX == \RequireNativeupTeX
\gdef\RequirenativeupTeX{\RequireNativeupTeX}

%%<+>D \ifnewupTeX
\global\bxip@false{ifnewupTeX}
\ifnum\upTeXguessedversion<\bxip@uptex@new@version\else
  \global\bxip@true{ifnewupTeX}
\fi

%%<+>D \RequireNewupTeX
\gdef\RequireNewupTeX{%
  \bxip@with@default\bxip@uptex@new@version\bxip@require@new@uptex@a}
\gdef\bxip@require@new@uptex@a[#1]{%
  \ifupTeX
    \bxip@check@version\upTeXguessedversion{#1}{upTeX}%
  \else \bxip@err@required{upTeX}%
  \fi}

%%<+>D \RequireNativeNewupTeX
\gdef\RequireNativeNewupTeX{%
  \bxip@with@default\bxip@uptex@new@version\bxip@require@new@uptex@b}
\gdef\bxip@require@new@uptex@b[#1]{%
  \ifnativeupTeX
    \bxip@check@version\upTeXguessedversion{#1}{upTeX in Unicode}%
  \else \bxip@err@required{upTeX in Unicode}%
  \fi}

%--------------------------------------- all done
\endgroup
\bxip@restore@codes
\endinput
%% EOF