pgfkeyslibraryconditionals.code.tex

\pgfkeys{
  /utils/ifname nTF/.code n args={3}{%
    \ifcsname if#1\endcsname
      \pgfkeys@lib@cond@gobble\if % paired \ifxxx ... (\else ...) \fi to cheat TeX
      \csname if#1\endcsname
        \expandafter\expandafter\expandafter\@firstoftwo
      \else
        \expandafter\expandafter\expandafter\@secondoftwo
      \fi
    \else
      \pgfkeys@error{Undefined \pgfkeys@lib@cond@backslashchar if#1 used by 
        ``\pgfkeyscurrentkey=\detokenize{{#1}{#2}{#3}}''.\pgfkeys@lib@cond@messagebreak%
        I'll use false branch}%
      \expandafter\@secondoftwo
    \fi
    {\pgfkeysalso{#2}}{\pgfkeysalso{#3}}%
  },
  /utils/ifxxx nTF/.code n args={3}{%
    #1%
      \expandafter\pgfkeys@firstoftwo
    \else
      \expandafter\pgfkeys@secondoftwo
    \fi
    {\pgfkeysalso{#2}}{\pgfkeysalso{#3}}%
  },
  /utils/ifnum nNnTF/.style n args={5}{
    /utils/ifxxx nTF={\ifnum\numexpr#1\relax#2\numexpr#3\relax}{#4}{#5}
  },
  /utils/ifdim nNnTF/.style n args= {5}{
    /utils/ifxxx nTF={\ifdim\dimexpr#1\relax#2\dimexpr#3\relax}{#4}{#5}
  },
  /utils/if NNTF/.style n args={4}{
    /utils/ifxxx nTF={\if\noexpand#1\noexpand#2}{#3}{#4}
  },
  /utils/ifcat NNTF/.style n args={4}{
    /utils/ifxxx nTF={\ifcat\noexpand#1\noexpand#2}{#3}{#4}
  },
  /utils/ifx NNTF/.style n args={4}{
    /utils/ifxxx nTF={\ifx#1#2}{#3}{#4}
  }
}

\ifdefined\PackageError
  \def\pgfkeys@lib@cond@messagebreak{\MessageBreak}
\else
  \def\pgfkeys@lib@cond@messagebreak{^^J}
\fi

\long\def\pgfkeys@lib@cond@gobble#1{}
\edef\pgfkeys@lib@cond@backslashchar{%
  \expandafter\pgfkeys@lib@cond@gobble\string\\}

% similar to \pgfsys@strcmp defined in pgfsys.code.tex
\ifdefined\pdfstrcmp
  \let\pgfkeys@lib@cond@strcmp=\pdfstrcmp
\else\ifdefined\strcmp
  \let\pgfkeys@lib@cond@strcmp=\strcmp
\else\ifdefined\directlua
  \directlua{
    local lft = lua.get_functions_table()
    lft[\string#lft+1] = function()
        local lhs = token.scan_string()
        local rhs = token.scan_string()
        if lhs < rhs then
            tex.sprint(-2, "-1")
        elseif lhs == rhs then
            tex.sprint(-2, "0")
        else
            tex.sprint(-2, "1")
        end
    end
    token.set_lua("pgfkeys@lib@cond@strcmp", \string#lft, "global")
  }
\fi\fi\fi

\ifdefined\pgfkeys@lib@cond@strcmp
  \long\def\pgfkeys@lib@cond@strcmp@do#1#2{%
    \pgfkeys@lib@cond@strcmp{\pgfkeys@unexpanded{#1}}{\pgfkeys@unexpanded{#2}}}
  \pgfkeys{
    /utils/if strcmp nNnTF/.style n args={5}{
      /utils/ifxxx nTF={\ifnum\pgfkeys@lib@cond@strcmp@do{#1}{#3}#20\relax}{#4}{#5}
    }
  }
  \pgfkeys@lib@cond@gobble\fi
\else
  \pgfkeys@error{%
    No primitive \pgfkeys@lib@cond@backslashchar(pdf)strcmp found and I'm not in LuaTeX.\pgfkeys@lib@cond@messagebreak
    ``/utils/if strcmp nNnTF'' is not provided}
\fi