tikzlibraryfunprog.code.tex

\usetikzlibrary {matrix}
\usetikzlibrary {positioning}
\usetikzlibrary {fit}
\usetikzlibrary {shapes.multipart}

\makeatletter

\pgfkeys{
  funprog/.is family,
  funprog/.search also=/tikz,
}

\let\funprog@datastructtype\empty
\let\funprog@datastructid\empty
\let\funprog@datastruct@element\empty
\def\funprog@datastruct@elementsize{1cm}
\def\funprog@datastruct@wrapperpadding{5mm}
\def\funprog@datastruct@wrapperlevel{0}
\let\funprog@placeholdersize\empty

\newcounter{placeholder}

\tikzset{
  element/.forward to={funprog, data struct element},
  element size/.forward to={funprog, data struct element size},
  wrapper/.forward to={funprog, data struct wrapper level},
  wrapper padding/.forward to={funprog, data struct wrapper padding},
  index/.forward to={funprog, \funprog@datastructtype/index},
  key value/.forward to={funprog, \funprog@datastructtype/key value},
  separator/.forward to={funprog, \funprog@datastructtype/separator},
  placeholder/.forward to={funprog, \funprog@datastructtype/placeholder},
  elements before/.forward to={funprog, \funprog@datastructtype/elements before},
  elements between/.forward to={funprog, \funprog@datastructtype/elements between},
  elements after/.forward to={funprog, \funprog@datastructtype/elements after},
  every elements before/.forward to={funprog, \funprog@datastructtype/every elements before},
  every elements between/.forward to={funprog, \funprog@datastructtype/every elements between},
  every elements after/.forward to={funprog, \funprog@datastructtype/every elements after},
}

\pgfkeys{
  funprog,
  data struct type/.store in=\funprog@datastructtype,
  data struct id/.store in=\funprog@datastructid,
  data struct element/.store in=\funprog@datastruct@element,
  data struct element size/.store in=\funprog@datastruct@elementsize,
  data struct wrapper level/.store in=\funprog@datastruct@wrapperlevel,
  data struct wrapper level/.default=1,
  data struct wrapper padding/.store in=\funprog@datastruct@wrapperpadding,
  data struct alias/.style={
    append after command={
      \pgfextra
      \node[name=#1, fit=(\tikzlastnode), inner sep=0pt] {};
      \endpgfextra
    },
  },
  reset placeholder counter/.code={
    \setcounter{placeholder}{0}
  },
  next placeholder counter/.code={
    \stepcounter{placeholder}
  },
}

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% tuple
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

\let\funprog@tuple@delimiter@left\empty
\let\funprog@tuple@delimiter@right\empty

\tikzset{
  every tuple/.style={},
  tuple/.forward to={funprog, tuple},
  tuple delimiter/.forward to={funprog, tuple/delimiter},
}

\pgfkeys{
  funprog,
  tuple/.style={
    data struct type=tuple,
    data struct id=#1,
    data struct element=#1,
    data struct alias=tuple #1,
    left delimiter=\funprog@tuple@delimiter@left,
    right delimiter=\funprog@tuple@delimiter@right,
    nodes={
      anchor=center,
      inner sep=0pt,
      outer sep=0pt,
    },
    column sep=-\pgflinewidth,
    row sep=-\pgflinewidth,
    outer sep=-.5\pgflinewidth,
    inner sep=0pt,
    every tuple,
    reset placeholder counter,
  },
  tuple/separator/.style={
    node contents={\,,\,\,},
  },
  tuple/placeholder/.style={
    next placeholder counter,
    alias={\funprog@datastructid placeholder\the\value{placeholder}},
    node contents={},
    minimum width=#1 * \funprog@datastruct@elementsize + 2 * \funprog@datastruct@wrapperlevel * \funprog@datastruct@wrapperpadding,
    minimum height=\funprog@datastruct@elementsize + 2 * \funprog@datastruct@wrapperpadding,
  },
  tuple/placeholder/.default=1,
  tuple/delimiter/left/.store in=\funprog@tuple@delimiter@left,
  tuple/delimiter/right/.store in=\funprog@tuple@delimiter@right,
  tuple/delimiter/.is choice,
  tuple/delimiter/parenthesis/.style={
    tuple/delimiter/left=(,
    tuple/delimiter/right=),
  },
  tuple/delimiter/braces/.style={
    tuple/delimiter/left=\{,
    tuple/delimiter/right=\},
  },
  tuple/delimiter/brackets/.style={
    tuple/delimiter/left=[,
    tuple/delimiter/right=],
  },
  tuple/delimiter=parenthesis,
  tuple/index/.style={
    alias=\funprog@datastructid#1,
    node contents={$\funprog@datastruct@element_{#1}$},
    minimum width=\funprog@datastruct@elementsize,
  },
  tuple/elements before/.style={
    node contents={\ldots},
  },
  tuple/elements between/.style={
    node contents={\ldots},
  },
  tuple/elements after/.style={
    node contents={\ldots},
  },
}

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% map
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

\tikzset{
  every map/.style={},
  map/.forward to={funprog, map},
}

\pgfkeys{
  funprog,
  map/.style={
    data struct type=map,
    data struct id=#1,
    data struct element=#1,
    data struct alias=map #1,
    nodes={
      draw,
      anchor=center,
      inner sep=0pt,
      outer sep=.5\pgflinewidth,
      minimum size=\funprog@datastruct@elementsize,
    },
    column sep=-\pgflinewidth,
    row sep=-\pgflinewidth,
    outer sep=-.5\pgflinewidth,
    inner sep=0pt,
    every list,
  },
  map/index/.style={
    alias=\funprog@datastructid#1,
    %node contents={$\funprog@datastruct@element_{#1}$},
    key value={$k_{#1}$}{$v_{#1}$}
  },
  map/key value/.style 2 args={
    node contents={},
    path picture={
        \coordinate (_funprog_n) at ($ (path picture bounding box.north) + (0, -.5\pgflinewidth) $);
        \coordinate (_funprog_s) at ($ (path picture bounding box.south) + (0, .5\pgflinewidth) $);
        \coordinate (_funprog_k) at ($ (_funprog_n)!.25!(_funprog_s) $);
        \coordinate (_funprog_v) at ($ (_funprog_n)!.75!(_funprog_s) $);
        \node (last key) [draw=none, fill=none, minimum size=0, anchor=base, yshift={height("x") / -2}] at (_funprog_k) {#1};
        \node (last value) [draw=none, fill=none, minimum size=0, anchor=base, yshift={height("x") / -2}] at (_funprog_v) {#2};
        \draw [line width=\pgflinewidth]
            (path picture bounding box.west) -- (path picture bounding box.east);
    },
    %append after command={
      %\pgfextra
      %\coordinate (_funprog_x)  ($ (\tikzlastnode.west)!.5!(\tikzlastnode.east) $);
      %\draw [line width=.75\pgflinewidth] 
        %($(\tikzlastnode.west) + (\pgflinewidth, 0) $) --
        %($(_funprog_x) + (-1mm, 0)$) --
        %($(_funprog_x) + (0, -1mm)$) --
        %($(_funprog_x) + (1mm, 0)$) --
        %($ (\tikzlastnode.east) + (-\pgflinewidth, 0) $);
      %\coordinate (_funprog_n) at ($ (\tikzlastnode.north) + (0, -.5\pgflinewidth) $);
      %\coordinate (_funprog_s) at ($ (\tikzlastnode.south) + (0, .5\pgflinewidth) $);
      %\coordinate (_funprog_k) at ($ (_funprog_n)!.25!(_funprog_s) $);
      %\coordinate (_funprog_v) at ($ (_funprog_n)!.75!(_funprog_s) $);
      %%\draw (n) circle [radius=1pt];
      %%\draw (s) circle [radius=1pt];
      %%\draw (k) circle [radius=1pt];
      %%\draw (v) circle [radius=1pt];
      %%\draw (\tikzlastnode.center) circle [radius=1pt];
      %%\coordinate (a) at ($ (\tikzlastnode.north)!.25!(\tikzlastnode.south) $);
      %%\draw [very thin, red] (\tikzlastnode.west |- k) -- (\tikzlastnode.east |- k);
      %%\draw [very thin, red] (\tikzlastnode.west |- v) -- (\tikzlastnode.east |- v);
      %%\node (k1) [anchor=base, yshift={height("x") / -2}] at (k) {x};
      %\node (last key) [draw=none, minimum size=0, anchor=base, yshift={height("x") / -2}] at (_funprog_k) {#1};
      %\node (last value) [draw=none, minimum size=0, anchor=base, yshift={height("x") / -2}] at (_funprog_v) {#2};
      %\endpgfextra
    %}
  },
  map/every elements before/.style={},
  map/elements before/.default=.5,
  map/elements before/.style={
    draw=none,
    fill=none,
    every elements before,
    node contents={},
    outer sep=0pt,
    minimum width=#1 * \funprog@datastruct@elementsize,
    minimum height=\funprog@datastruct@elementsize,
    path picture={
        \draw [dashed]
            (path picture bounding box.north west) -- (path picture bounding box.north east)
            (path picture bounding box.south east) -- (path picture bounding box.south west);
    },
    %append after command={
      %\pgfextra
      %\draw [dashed]
            %(\tikzlastnode.north west) -- (\tikzlastnode.north east)
            %(\tikzlastnode.south west) -- (\tikzlastnode.south east);
      %\endpgfextra
    %},
  },
  map/every elements between/.style={},
  map/elements between/.default=.5,
  map/elements between/.style={
    draw=none,
    fill=none,
    every elements between,
    node contents={},
    outer sep=0pt,
    minimum width=#1 * \funprog@datastruct@elementsize,
    minimum height=\funprog@datastruct@elementsize,
    path picture={
        \draw [dashed]
            (path picture bounding box.north west) -- (path picture bounding box.north east)
            (path picture bounding box.south east) -- (path picture bounding box.south west);
    },
    %append after command={
      %\pgfextra
      %\draw [dashed]
            %(\tikzlastnode.north west) -- (\tikzlastnode.north east)
            %(\tikzlastnode.south west) -- (\tikzlastnode.south east);
      %\endpgfextra
    %},
  },
  map/every elements after/.style={},
  map/elements after/.default=.5,
  map/elements after/.style={
    draw=none,
    fill=none,
    every elements after,
    node contents={},
    outer sep=0pt,
    minimum width=#1 * \funprog@datastruct@elementsize,
    minimum height=\funprog@datastruct@elementsize,
    path picture={
        \draw [dashed]
            (path picture bounding box.north west) -- (path picture bounding box.north east)
            (path picture bounding box.south east) -- (path picture bounding box.south west);
    },
    %append after command={
      %\pgfextra
      %\draw [dashed]
            %(\tikzlastnode.north west) -- (\tikzlastnode.north east)
            %(\tikzlastnode.south west) -- (\tikzlastnode.south east);
      %\endpgfextra
    %},
  },
}

% empty collection ------------------------------------------------------------

\tikzset{
  every empty collection/.style={},
  empty collection/.forward to={funprog, empty collection},
}

\pgfkeys{
  funprog,
  empty collection/.style={
    every empty collection,
    %data struct id=#1,
    %data struct element=#1,
    %data struct alias=list #1,
    alias=empty collection #1,
    draw,
    densely dashed,
    node contents={},
    inner sep=0pt,
    outer sep=.5\pgflinewidth,
    minimum height=\funprog@datastruct@elementsize,
    minimum width=.3 * \funprog@datastruct@elementsize,
  },
}

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% list
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

\tikzset{
  every list/.style={},
  list/.forward to={funprog, list},
}

\pgfkeys{
  funprog,
  list/.style={
    data struct type=list,
    data struct id=#1,
    data struct element=#1,
    data struct alias=list #1,
    nodes={
      draw,
      anchor=center,
      inner sep=0pt,
      outer sep=0pt,
      minimum size=\funprog@datastruct@elementsize + 2 * \funprog@datastruct@wrapperlevel * \funprog@datastruct@wrapperpadding,
    },
    column sep=-\pgflinewidth,
    row sep=-\pgflinewidth,
    outer sep=-.5\pgflinewidth,
    inner sep=0pt,
    every list,
    reset placeholder counter,
  },
  list/.default=a,
  list/placeholder/.style={
    next placeholder counter,
    alias={\funprog@datastructid placeholder\the\value{placeholder}},
    node contents={},
    minimum width=#1 * \funprog@datastruct@elementsize + 2 * \funprog@datastruct@wrapperlevel * \funprog@datastruct@wrapperpadding,
  },
  list/placeholder/.default=1,
  list/index/.style={
    alias=\funprog@datastructid#1,
    node contents={$\funprog@datastruct@element_{#1}$},
  },
  list/every elements before/.style={},
  list/elements before/.default=.5,
  list/elements before/.style={
    draw=none,
    fill=none,
    every elements before,
    node contents={},
    outer sep=0pt,
    minimum width=#1 * \funprog@datastruct@elementsize,
    path picture={
        \draw [dashed]
            (path picture bounding box.north west) -- (path picture bounding box.north east)
            (path picture bounding box.south east) -- (path picture bounding box.south west);
    },
    %append after command={
      %\pgfextra
      %\draw [dashed]
            %(\tikzlastnode.north west) -- (\tikzlastnode.north east)
            %(\tikzlastnode.south west) -- (\tikzlastnode.south east);
      %\endpgfextra
    %},
  },
  list/every elements between/.style={},
  list/elements between/.default=.5,
  list/elements between/.style={
      draw=none,
      fill=none,
      every elements between,
      outer sep=0pt,
      node contents={},
      minimum width=#1 * \funprog@datastruct@elementsize,
      path picture={
        \draw [dashed]
            (path picture bounding box.north west) -- (path picture bounding box.north east)
            (path picture bounding box.south east) -- (path picture bounding box.south west);
      },
    %append after command={
      %\pgfextra{
        %\draw [draw=\pgfkeysvalueof{/pgf/color}, dashed]
            %(\tikzlastnode.north west) -- (\tikzlastnode.north east)
            %(\tikzlastnode.south west) -- (\tikzlastnode.south east);
      %}
    %},
  },
  list/every elements after/.style={},
  list/elements after/.default=.5,
  list/elements after/.style={
    draw=none,
    fill=none,
    every elements after,
    node contents={},
    outer sep=0pt,
    minimum width=#1 * \funprog@datastruct@elementsize,
    path picture={
        \draw [dashed]
            (path picture bounding box.north west) -- (path picture bounding box.north east)
            (path picture bounding box.south east) -- (path picture bounding box.south west);
    },
    %append after command={
      %\pgfextra
      %\draw [dashed]
            %(\tikzlastnode.north west) -- (\tikzlastnode.north east)
            %(\tikzlastnode.south west) -- (\tikzlastnode.south east);
      %\endpgfextra
    %},
  },
}

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% interval
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

\tikzset{
  every interval/.style={},
  interval/.forward to={funprog, interval},
  interval amplitude/.forward to={funprog, interval/amplitude},
  interval segments/.forward to={funprog, interval/segments},
}

\pgfkeys{
  funprog,
  interval/.style={
    decorate,
    decoration={
      show path construction,
      lineto code={
        \path
        let
          \p1=(\tikzinputsegmentfirst),
          \p2=(\tikzinputsegmentlast),
          \n1={abs(\x2 - \x1)},
          \n2={abs(\y2 - \y1) + \funprog@interval@amplitude}
        in
            node at ($ (\p1) + (0, \n2) $) [name=interval #1, anchor=north west, minimum width=\n1, minimum height=2 * \n2, inner sep=0, outer sep=0] {};
        \foreach [remember=\pos as \lastpos (initially 0), count=\i] \pos/\style in \funprog@interval@segments{
          \draw
            [/tikz/every interval, /funprog/interval/style=\style]
          let
            \p1=(\tikzinputsegmentfirst),
            \p2=(\tikzinputsegmentlast),
            \n1={veclen(\x2 - \x1, \y2 - \y1)},
            \p{unit}=({(\x2 - \x1) / \n1}, {(\y2 - \y1) / \n1}),
            \n2={\pgf@x * sign(\x2 - \x1)},
            \n3={\pgf@y * sign(\y2 - \y1)},
            \p{start}=(\x1 + \lastpos * \n1 * \x{unit}, \y1 + \lastpos * \n1 * \y{unit}),
            \p{end}=(\x1 + \pos * \n1 * \x{unit}, \y1 + \pos * \n1 * \y{unit}),
            \n4={int(\i + 1)}
          in
            (\p{start})
               coordinate (interval #1 mark \i)
            -- +(-\y{unit} * \funprog@interval@amplitude, \x{unit} * \funprog@interval@amplitude)
               coordinate (interval #1 mark top \i)
            -- +(0, 0)
            -- +(\y{unit} * \funprog@interval@amplitude, -\x{unit} * \funprog@interval@amplitude)
               coordinate (interval #1 mark bottom \i)
            -- +(0, 0)
            -- (\p{end}) 
               coordinate (interval #1 mark \n4)
            -- +(-\y{unit} * \funprog@interval@amplitude, \x{unit} * \funprog@interval@amplitude)
               coordinate (interval #1 mark top \n4)
            -- +(0, 0)
            -- +(\y{unit} * \funprog@interval@amplitude, -\x{unit} * \funprog@interval@amplitude)
               coordinate (interval #1 mark bottom \n4)
            -- +(0, 0)
          ;
        }
      }
    }
  },
  interval/amplitude/.store in=\funprog@interval@amplitude,
  interval/amplitude=5mm,
  interval/segments/.store in=\funprog@interval@segments,
  interval/segments={1/solid},
  interval/style/.is choice,
  interval/style/solid/.style={solid},
  interval/style/dashed/.style={dashed},
}

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% iteration
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

\tikzset{
  iteration position/.forward to={funprog, iteration/position},
  iteration direction/.forward to={funprog, iteration/direction},
  enter iteration start angle/.forward to={funprog, iteration/enter start angle},
  enter iteration delta angle/.forward to={funprog, iteration/enter delta angle},
  exit iteration start angle/.forward to={funprog, iteration/exit start angle},
  exit iteration delta angle/.forward to={funprog, iteration/exit delta angle},
  every enter iteration/.style={},
  enter iteration/.forward to={
    funprog, iteration/enter/\pgfkeysvalueof{/funprog/iteration/position}/\pgfkeysvalueof{/funprog/iteration/direction}=#1
  },
  every iteration/.style={},
  iteration/.forward to={
    funprog, iteration/direct/\pgfkeysvalueof{/funprog/iteration/position}/\pgfkeysvalueof{/funprog/iteration/direction}=#1
  },
  every exit iteration/.style={},
  exit iteration/.forward to={
    funprog, iteration/exit/\pgfkeysvalueof{/funprog/iteration/position}/\pgfkeysvalueof{/funprog/iteration/direction}=#1
  },
}

\pgfkeys{
  funprog,
  iteration/position/.initial=above,
  iteration/direction/.initial=from left to right,
  iteration/enter start angle/.initial=30,
  iteration/enter delta angle/.initial=90,
  iteration/exit start angle/.initial=150,
  iteration/exit delta angle/.initial=90,
  iteration/enter/above/from left to right/.style={
    decorate,
    decoration={
      show path construction,
      moveto code={
        \draw [
          start angle=\pgfkeysvalueof{/funprog/iteration/enter start angle},
          delta angle=\pgfkeysvalueof{/funprog/iteration/enter delta angle},
          radius=1cm,
          every enter iteration,
          #1
        ] (\tikzinputsegmentfirst) arc coordinate (last iteration);
      },
    }
  },
  iteration/enter/above/from right to left/.style={
    decorate,
    decoration={
      show path construction,
      moveto code={
        \draw [
          start angle=180 - \pgfkeysvalueof{/funprog/iteration/enter start angle},
          delta angle=-\pgfkeysvalueof{/funprog/iteration/enter delta angle},
          radius=1cm,
          every enter iteration,
          #1
        ] (\tikzinputsegmentfirst) arc coordinate (last iteration);
      },
    }
  },
  iteration/direct/above/from left to right/.style={
    decorate,
    decoration={
      show path construction,
      lineto code={
        \draw [bend left=45, every iteration, #1] (\tikzinputsegmentfirst) to coordinate (last iteration) (\tikzinputsegmentlast);
      },
    }
  },
  iteration/direct/above/from right to left/.style={
    decorate,
    decoration={
      show path construction,
      lineto code={
        \draw [bend right=45, every iteration, #1] (\tikzinputsegmentfirst) to (\tikzinputsegmentlast);
      },
    }
  },
  iteration/exit/above/from left to right/.style={
    decorate,
    decoration={
      show path construction,
      moveto code={
        \draw [
          start angle=\pgfkeysvalueof{/funprog/iteration/exit start angle},
          delta angle=-\pgfkeysvalueof{/funprog/iteration/exit delta angle},
          radius=1cm,
          every exit iteration,
          #1
        ] (\tikzinputsegmentfirst) arc coordinate (last iteration);
      },
    }
  },
  iteration/exit/above/from right to left/.style={
    decorate,
    decoration={
      show path construction,
      moveto code={
        \draw [
          start angle=180 - \pgfkeysvalueof{/funprog/iteration/exit start angle},
          delta angle=\pgfkeysvalueof{/funprog/iteration/exit delta angle},
          radius=1cm,
          every exit iteration,
          #1
] (\tikzinputsegmentfirst) arc coordinate (last iteration);
      },
    }
  },
}

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% measure
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

\def\funprog@measure@position@above{1}
\def\funprog@measure@position@below{-1}
\let\funprog@measure@position\funprog@measure@position@above

\tikzset{
  measure/.forward to={funprog, measure},
  measure amplitude/.forward to={funprog, measure amplitude},
  measure overflow/.forward to={funprog, measure overflow},
  measure position/.forward to={funprog, measure position},
  every measure arrow/.style={
    -{Triangle[angle=30:1mm 2mm]},
  },
}

\pgfkeys{
  funprog,
  measure amplitude/.initial=5mm,
  measure overflow/.initial=1mm,
  measure position/.is choice,
  measure position/above/.code={
    \let\funprog@measure@position\funprog@measure@position@above
  },
  measure position/below/.code={
    \let\funprog@measure@position\funprog@measure@position@below
  },
  measure/.default={},
  measure/.style={
    decorate,
    decoration={
      show path construction,
      lineto code={
        \path let
          \p1=(\tikzinputsegmentfirst),
          \p2=(\tikzinputsegmentlast),
          \p3=(\x2 - \x1, \y2 - \y1),
          \n1={veclen(\x3, \y3)},
          \p4=(-\y3 / \n1, \x3 / \n1),
          \n2={\funprog@measure@position * \pgfkeysvalueof{/funprog/measure amplitude}},
          \n3={\pgfkeysvalueof{/funprog/measure overflow} * \funprog@measure@position * sign(\pgfkeysvalueof{/funprog/measure amplitude})}
        in
          coordinate (last measure point a) at ($ (\p1) + (\x4 * \n2, \y4 * \n2) $)
          coordinate (last measure point b) at ($ (\p2) + (\x4 * \n2, \y4 * \n2) $)
          coordinate (last measure point c) at ($ (last measure point a) + (\x4 * \n3, \y4 * \n3) $)
          coordinate (last measure point d) at ($ (last measure point b) + (\x4 * \n3, \y4 * \n3) $)
          coordinate (last measure label) at ($ (last measure point a)!.5!(last measure point b) $)
        ;
        \draw (\tikzinputsegmentfirst) -- (last measure point c);
        \draw (\tikzinputsegmentlast) -- (last measure point d);
        \path let
          \p1=(\tikzinputsegmentfirst),
          \p2=(\tikzinputsegmentlast),
          \p3=(\x2 - \x1, \y2 - \y1),
          \n1={atan2(\y3, \x3)}
        in
         node (last measure label) at (last measure label) [rotate=\n1] {#1};
        \draw [every measure arrow] (last measure label) -- (last measure point a);
        \draw [every measure arrow] (last measure label) -- (last measure point b);
      }
    }
  }
}


%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% brace
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

\tikzset{
  every brace/.style={},
  brace/.forward to={funprog, brace},
  brace amplitude/.forward to={funprog, brace amplitude},
  brace raise/.forward to={funprog, brace raise},
}

\pgfkeys{
  funprog,
  brace amplitude/.initial=1mm,
  brace raise/.initial=0,
  brace/.style={
    decorate,
    decoration={
      show path construction,
      lineto code={
        \draw
          [every brace, decorate, decoration={brace, amplitude=\pgfkeysvalueof{/funprog/brace amplitude}, raise=\pgfkeysvalueof{/funprog/brace raise}}] 
          (\tikzinputsegmentfirst) -- (\tikzinputsegmentlast);
        \draw let
          \p1=(\tikzinputsegmentfirst),
          \p2=(\tikzinputsegmentlast),
          \p3=($ (\p2) - (\p1) $),
          \n1={veclen(\x3, \y3)},
          \p4=(-\y3 / \n1, \x3 / \n1),
          \n2={\pgfkeysvalueof{/funprog/brace amplitude} + \pgfkeysvalueof{/funprog/brace raise}},
          \p5=(\x4 * \n2, \y4 * \n2)
        in
          coordinate (last brace) at ($ ($ (\p1)!.5!(\p2) $) + (\x5, \y5) $);
      }
    }
  }
}

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% function
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

\def\pgfutil@useanchor#1#2{\csname pgf@anchor@#1@#2\endcsname}

\def\funprog@function@north{1}
\def\funprog@function@south{2}
\def\funprog@function@east{3}
\def\funprog@function@west{4}

\let\funprog@function@in\funprog@function@north
\let\funprog@function@out\funprog@function@south
\def\funprog@function@arity{1}

\tikzset{
  every function/.style={},
  function/.forward to={funprog, function=#1},
  function arity/.forward to={funprog, function/arity=#1},
  function in/.forward to={funprog, function/in=#1},
  function out/.forward to={funprog, function/out=#1},
  function port width/.forward to={funprog, function/port width},
  function port height/.forward to={funprog, function/port height},
  function port funnel width/.forward to={funprog, function/port funnel width},
  function port separation/.forward to={funprog, function/port separation},
}

\pgfkeys{
  funprog,
  function/.style={
    alias=function #1,
    draw,
    shape=function,
    every function,
    node contents=#1,
  },
  %
  function/.cd,
  port width/.initial=2.5mm,
  port height/.initial=1mm,
  port funnel width/.initial=1.75mm,
  port separation/.initial=2.5mm,
  north ports/.initial=1,
  south ports/.initial=1,
  east ports/.initial=0,
  west ports/.initial=0,
}

\def\funprog@function@update{
  \pgfkeys{
    funprog,
    function/.cd,
    north ports=0,
    south ports=0,
    east ports=0,
    west ports=0,
  }
  %
  \ifnum\funprog@function@in=\funprog@function@north
  \pgfkeysalso{/funprog/function/north ports=\funprog@function@arity}
  \fi
  \ifnum\funprog@function@in=\funprog@function@south
  \pgfkeysalso{/funprog/function/south ports=\funprog@function@arity}
  \fi
  \ifnum\funprog@function@in=\funprog@function@west
  \pgfkeysalso{/funprog/function/west ports=\funprog@function@arity}
  \fi
  \ifnum\funprog@function@in=\funprog@function@east
  \pgfkeysalso{/funprog/function/east ports=\funprog@function@arity}
  \fi
  %
  \ifnum\funprog@function@out=\funprog@function@north
  \pgfkeysalso{/funprog/function/north ports=1}
  \fi
  \ifnum\funprog@function@out=\funprog@function@south
  \pgfkeysalso{/funprog/function/south ports=1}
  \fi
  \ifnum\funprog@function@out=\funprog@function@west
  \pgfkeysalso{/funprog/function/west ports=1}
  \fi
  \ifnum\funprog@function@out=\funprog@function@east
  \pgfkeysalso{/funprog/function/east ports=1}
  \fi
}

\pgfkeys{
  funprog,
  function/.cd,
  in/.is choice,
  in/north/.code={
    \let\funprog@function@in\funprog@function@north
    \funprog@function@update
  },
  in/south/.code={
    \let\funprog@function@in\funprog@function@south
    \funprog@function@update
  },
  in/east/.code={
    \let\funprog@function@in\funprog@function@east
    \funprog@function@update
  },
  in/west/.code={
    \let\funprog@function@in\funprog@function@west
    \funprog@function@update
  },
  %
  out/.is choice,
  out/north/.code={
    \let\funprog@function@out\funprog@function@north
    \funprog@function@update
  },
  out/south/.code={
    \let\funprog@function@out\funprog@function@south
    \funprog@function@update
  },
  out/east/.code={
    \let\funprog@function@out\funprog@function@east
    \funprog@function@update
  },
  out/west/.code={
    \let\funprog@function@out\funprog@function@west
    \funprog@function@update
  },
  %
  arity/.code={
    \def\funprog@function@arity{#1}
    \funprog@function@update
  },
  %
  in=north,
  out=south,
  arity=1
}

% sets \pgf@x and \pgf@y to the south west corner of the function box
\def\funprog@function@anchor@southwest{
  \pgfmathsetlength\@tempdima{\pgfkeysvalueof{/funprog/function/port width} + \pgfkeysvalueof{/funprog/function/port separation}}
  %
  % Calculate x
  %
  % First, is width < minimum width?
  \pgf@x=\wd\pgfnodeparttextbox%
  \pgfmathsetlength\pgf@xc{\pgfkeysvalueof{/pgf/inner xsep}}%
  \advance\pgf@x by 2\pgf@xc%
  \pgfmathsetlength\pgf@xb{\pgfkeysvalueof{/pgf/minimum width}}%
  \ifdim\pgf@x<\pgf@xb%
  % yes, too small. Enlarge...
  \pgf@x=\pgf@xb%
  \fi%
  \pgfmathsetlength\pgf@xa{\pgfkeysvalueof{/funprog/function/north ports} * \@tempdima}
  \ifdim\pgf@x<\pgf@xa%
  % yes, too small. Enlarge...
  \pgf@x=\pgf@xa%
  \fi%
  \pgfmathsetlength\pgf@xa{\pgfkeysvalueof{/funprog/function/south ports} * \@tempdima}
  \ifdim\pgf@x<\pgf@xa%
  % yes, too small. Enlarge...
  \pgf@x=\pgf@xa%
  \fi%
  % Now, calculate left border: .5\wd\pgfnodeparttextbox - .5 \pgf@x - outer sep
  \pgf@x=-.5\pgf@x%
  \advance\pgf@x by.5\wd\pgfnodeparttextbox%
  \pgfmathsetlength\pgf@xa{\pgfkeysvalueof{/pgf/outer xsep}}%
  \advance\pgf@x by-\pgf@xa%
  %
  % Calculate y
  %
  % First, is height+depth < minimum height?
  \pgf@y=\ht\pgfnodeparttextbox%
  \advance\pgf@y by\dp\pgfnodeparttextbox%
  \pgfmathsetlength\pgf@yc{\pgfkeysvalueof{/pgf/inner ysep}}%
  \advance\pgf@y by 2\pgf@yc%
  \pgfmathsetlength\pgf@yb{\pgfkeysvalueof{/pgf/minimum height}}%
  \ifdim\pgf@y<\pgf@yb%
  % yes, too small. Enlarge...
  \pgf@y=\pgf@yb%
  \fi%
  \pgfmathsetlength\pgf@ya{\pgfkeysvalueof{/funprog/function/east ports} * \@tempdima}
  \ifdim\pgf@y<\pgf@ya%
  % yes, too small. Enlarge...
  \pgf@y=\pgf@ya%
  \fi%
  \pgfmathsetlength\pgf@ya{\pgfkeysvalueof{/funprog/function/west ports} * \@tempdima}
  \ifdim\pgf@y<\pgf@ya%
  % yes, too small. Enlarge...
  \pgf@y=\pgf@ya%
  \fi%
  % Now, calculate upper border: .5\ht-.5\dp - .5 \pgf@y - outer sep
  \pgf@y=-.5\pgf@y%
  \advance\pgf@y by-.5\dp\pgfnodeparttextbox%
  \advance\pgf@y by.5\ht\pgfnodeparttextbox%
  \pgfmathsetlength\pgf@ya{\pgfkeysvalueof{/pgf/outer ysep}}%
  \advance\pgf@y by-\pgf@ya%
}

% sets \pgf@x and \pgf@y to the north east corner of the function box
\def\funprog@function@anchor@northeast{
  \pgfmathsetlength\@tempdima{\pgfkeysvalueof{/funprog/function/port width} + \pgfkeysvalueof{/funprog/function/port separation}}
  %
  % Calculate x
  %
  % First, is width < minimum width?
  \pgf@x=\the\wd\pgfnodeparttextbox%
  \pgfmathsetlength\pgf@xc{\pgfkeysvalueof{/pgf/inner xsep}}%
  \advance\pgf@x by 2\pgf@xc%
  \pgfmathsetlength\pgf@xb{\pgfkeysvalueof{/pgf/minimum width}}%
  \ifdim\pgf@x<\pgf@xb%
  % yes, too small. Enlarge...
  \pgf@x=\pgf@xb%
  \fi%
  \pgfmathsetlength\pgf@xa{\pgfkeysvalueof{/funprog/function/north ports} * \@tempdima}
  \ifdim\pgf@x<\pgf@xa%
  % yes, too small. Enlarge...
  \pgf@x=\pgf@xa%
  \fi%
  \pgfmathsetlength\pgf@xa{\pgfkeysvalueof{/funprog/function/south ports} * \@tempdima}
  \ifdim\pgf@x<\pgf@xa%
  % yes, too small. Enlarge...
  \pgf@x=\pgf@xa%
  \fi%
  % Now, calculate right border: .5\wd\pgfnodeparttextbox + .5 \pgf@x + outer sep
  \pgf@x=.5\pgf@x%
  \advance\pgf@x by.5\wd\pgfnodeparttextbox%
  \pgfmathsetlength\pgf@xa{\pgfkeysvalueof{/pgf/outer xsep}}%
  \advance\pgf@x by\pgf@xa%
  %
  % Calculate y
  %
  % First, is height+depth < minimum height?
  \pgf@y=\ht\pgfnodeparttextbox%
  \advance\pgf@y by\dp\pgfnodeparttextbox%
  \pgfmathsetlength\pgf@yc{\pgfkeysvalueof{/pgf/inner ysep}}%
  \advance\pgf@y by 2\pgf@yc%
  \pgfmathsetlength\pgf@yb{\pgfkeysvalueof{/pgf/minimum height}}%
  \ifdim\pgf@y<\pgf@yb%
  % yes, too small. Enlarge...
  \pgf@y=\pgf@yb%
  \fi%
  \pgfmathsetlength\pgf@ya{\pgfkeysvalueof{/funprog/function/east ports} * \@tempdima}
  \ifdim\pgf@y<\pgf@ya%
  % yes, too small. Enlarge...
  \pgf@y=\pgf@ya%
  \fi%
  \pgfmathsetlength\pgf@ya{\pgfkeysvalueof{/funprog/function/west ports} * \@tempdima}
  \ifdim\pgf@y<\pgf@ya%
  % yes, too small. Enlarge...
  \pgf@y=\pgf@ya%
  \fi%
  % Now, calculate upper border: .5\ht-.5\dp + .5 \pgf@y + outer sep
  \pgf@y=.5\pgf@y%
  \advance\pgf@y by-.5\dp\pgfnodeparttextbox%
  \advance\pgf@y by.5\ht\pgfnodeparttextbox%
  \pgfmathsetlength\pgf@ya{\pgfkeysvalueof{/pgf/outer ysep}}%
  \advance\pgf@y by\pgf@ya%
}

% draws a port
\def\funprog@function@portpath{
  \pgf@xa=0pt
  \pgf@ya=0pt
  \advance\pgf@xa by\halfportseparation
  \advance\pgf@xa by\halfportshadow
  \pgfpathlineto{\pgfqpoint{\pgf@xa}{\pgf@ya}}
  \pgf@xb=\pgf@xa \pgf@yb=\pgf@ya
  \advance\pgf@xa by-\halfportshadow
  \advance\pgf@ya by\portheight
  {
    \edef\funprog@xa{\the\pgf@xa}
    \edef\funprog@ya{\the\pgf@ya}
    \edef\funprog@xb{\the\pgf@xb}
    \edef\funprog@yb{\the\pgf@yb}
    \pgfcurveto
    {\pgfpoint{\funprog@xb}{\funprog@yb + \halfportheight}}
    {\pgfpoint{\funprog@xa}{\funprog@ya - \halfportheight}}
    {\pgfpoint{\funprog@xa}{\funprog@ya}}
  }
  \pgf@xb=\pgf@xa \pgf@yb=\pgf@ya
  \advance\pgf@xa by\portwidth
  \pgfpathlineto{\pgfqpoint{\pgf@xa}{\pgf@ya}}

  \pgf@xb=\pgf@xa \pgf@yb=\pgf@ya
  \advance\pgf@xa by-\halfportshadow
  \advance\pgf@ya by-\portheight
  {
    \edef\funprog@xa{\the\pgf@xa}
    \edef\funprog@ya{\the\pgf@ya}
    \edef\funprog@xb{\the\pgf@xb}
    \edef\funprog@yb{\the\pgf@yb}
    \pgfcurveto
    {\pgfpoint{\funprog@xb}{\funprog@yb - \halfportheight}}
    {\pgfpoint{\funprog@xa}{\funprog@ya + \halfportheight}}
    {\pgfpoint{\funprog@xa}{\funprog@ya}}
  }
% \pgfpathlineto{\pgfqpoint{\pgf@xa}{\pgf@ya}}
  \advance\pgf@xa by\halfportshadow
  \advance\pgf@xa by\halfportseparation
  \pgfpathlineto{\pgfqpoint{\pgf@xa}{\pgf@ya}}
}

\pgfdeclareshape{function}{%
  \inheritanchor[from=rectangle]{base}
  \inheritanchor[from=rectangle]{center}
  \inheritanchor[from=rectangle]{mid}
  \inheritanchor[from=rectangle]{north west}
  \inheritanchor[from=rectangle]{north east}
  \inheritanchor[from=rectangle]{south east}
  \inheritanchor[from=rectangle]{south west}

  \savedanchor\southwest{%
    \funprog@function@anchor@southwest
  }

  \savedanchor\northeast{%
    \funprog@function@anchor@northeast
  }

  \savedanchor\northeastincludingports{
    \pgf@process{\funprog@function@anchor@northeast}
    \ifnum\pgfkeysvalueof{/funprog/function/north ports}>0
    \advance\pgf@y by\pgfkeysvalueof{/funprog/function/port height}
    \fi
    \ifnum\pgfkeysvalueof{/funprog/function/east ports}>0
    \advance\pgf@x by\pgfkeysvalueof{/funprog/function/port height}
    \fi
  }

  \savedanchor\southwestincludingports{
    \funprog@function@anchor@southwest
    \ifnum\pgfkeysvalueof{/funprog/function/south ports}>0
    \advance\pgf@y by-\pgfkeysvalueof{/funprog/function/port height}
    \fi
    \ifnum\pgfkeysvalueof{/funprog/function/west ports}>0
    \advance\pgf@x by-\pgfkeysvalueof{/funprog/function/port height}
    \fi
  }

  \savedanchor\firstin{
    \ifnum\funprog@function@in=\funprog@function@north
      \pgf@process{\funprog@function@anchor@southwest} \pgf@xa=\pgf@x
      \pgf@process{\funprog@function@anchor@northeast}
      \pgfmathsetlength\pgf@x{.5*(\pgf@x + \pgf@xa)}
      \advance \pgf@y by\pgfkeysvalueof{/funprog/function/port height}
      \pgfkeysgetvalue{/funprog/function/port width}{\pgf@xa}
      \pgfkeysgetvalue{/funprog/function/port separation}{\pgf@xb}
      \pgfkeysgetvalue{/funprog/function/north ports}{\pgf@xc}
      \pgfmathsetlength\@tempdima{\pgf@xc * (\pgf@xa + \pgf@xb)}
      \advance \pgf@x by-.5\@tempdima
      \pgfmathsetlength\@tempdima{\pgf@xa / 2 + \pgf@xb / 2}
      \advance \pgf@x by\@tempdima
    \fi
    \ifnum\funprog@function@in=\funprog@function@south
      \pgf@process{\funprog@function@anchor@northeast} \pgf@xa=\pgf@x
      \pgf@process{\funprog@function@anchor@southwest}
      \pgfmathsetlength\pgf@x{.5*(\pgf@x + \pgf@xa)}
      \advance \pgf@y by-\pgfkeysvalueof{/funprog/function/port height}
      \pgfkeysgetvalue{/funprog/function/port width}{\pgf@xa}
      \pgfkeysgetvalue{/funprog/function/port separation}{\pgf@xb}
      \pgfkeysgetvalue{/funprog/function/south ports}{\pgf@xc}
      \pgfmathsetlength\@tempdima{\pgf@xc * (\pgf@xa + \pgf@xb)}
      \advance \pgf@x by-.5\@tempdima
      \pgfmathsetlength\@tempdima{\pgf@xa / 2 + \pgf@xb / 2}
      \advance \pgf@x by\@tempdima
    \fi
    \ifnum\funprog@function@in=\funprog@function@east
      \pgf@process{\funprog@function@anchor@southwest} \pgf@ya=\pgf@y
      \pgf@process{\funprog@function@anchor@northeast}
      \pgfmathsetlength\pgf@y{.5 * (\pgf@y + \pgf@ya)}
      \advance \pgf@x by\pgfkeysvalueof{/funprog/function/port height}
      \pgfkeysgetvalue{/funprog/function/port width}{\pgf@ya}
      \pgfkeysgetvalue{/funprog/function/port separation}{\pgf@yb}
      \pgfkeysgetvalue{/funprog/function/east ports}{\pgf@yc}
      \pgfmathsetlength\@tempdima{\pgf@yc * (\pgf@ya + \pgf@yb)}
      \advance \pgf@y by.5\@tempdima
      \pgfmathsetlength\@tempdima{\pgf@ya / 2 + \pgf@yb / 2}
      \advance \pgf@y by-\@tempdima
    \fi
    \ifnum\funprog@function@in=\funprog@function@west
      \pgf@process{\funprog@function@anchor@northeast} \pgf@ya=\pgf@y
      \pgf@process{\funprog@function@anchor@southwest}
      \pgfmathsetlength\pgf@y{.5 * (\pgf@y + \pgf@ya)}
      \advance \pgf@x by-\pgfkeysvalueof{/funprog/function/port height}
      \pgfkeysgetvalue{/funprog/function/port width}{\pgf@ya}
      \pgfkeysgetvalue{/funprog/function/port separation}{\pgf@yb}
      \pgfkeysgetvalue{/funprog/function/west ports}{\pgf@yc}
      \pgfmathsetlength\@tempdima{\pgf@yc * (\pgf@ya + \pgf@yb)}
      \advance \pgf@y by.5\@tempdima
      \pgfmathsetlength\@tempdima{\pgf@ya / 2 + \pgf@yb / 2}
      \advance \pgf@y by-\@tempdima
    \fi
  }

  \savedanchor\secondin{
    \ifnum\funprog@function@in=\funprog@function@north
      \pgf@process{\funprog@function@anchor@southwest} \pgf@xa=\pgf@x
      \pgf@process{\funprog@function@anchor@northeast}
      \pgfmathsetlength\pgf@x{.5*(\pgf@x + \pgf@xa)}
      \advance \pgf@y by\pgfkeysvalueof{/funprog/function/port height}
      \pgfkeysgetvalue{/funprog/function/port width}{\pgf@xa}
      \pgfkeysgetvalue{/funprog/function/port separation}{\pgf@xb}
      \pgfkeysgetvalue{/funprog/function/north ports}{\pgf@xc}
      \pgfmathsetlength\@tempdima{\pgf@xc * (\pgf@xa + \pgf@xb)}
      \advance \pgf@x by-.5\@tempdima
      \pgfmathsetlength\@tempdima{\pgf@xa / 2 + \pgf@xb / 2}
      \advance \pgf@x by\@tempdima
      \pgfmathsetlength\@tempdima{\pgf@xa + \pgf@xb}
      \advance \pgf@x by\@tempdima
    \fi
    \ifnum\funprog@function@in=\funprog@function@south
      \pgf@process{\funprog@function@anchor@northeast} \pgf@xa=\pgf@x
      \pgf@process{\funprog@function@anchor@southwest}
      \pgfmathsetlength\pgf@x{.5*(\pgf@x + \pgf@xa)}
      \advance \pgf@y by-\pgfkeysvalueof{/funprog/function/port height}
      \pgfkeysgetvalue{/funprog/function/port width}{\pgf@xa}
      \pgfkeysgetvalue{/funprog/function/port separation}{\pgf@xb}
      \pgfkeysgetvalue{/funprog/function/south ports}{\pgf@xc}
      \pgfmathsetlength\@tempdima{\pgf@xc * (\pgf@xa + \pgf@xb)}
      \advance \pgf@x by-.5\@tempdima
      \pgfmathsetlength\@tempdima{\pgf@xa / 2 + \pgf@xb / 2}
      \advance \pgf@x by\@tempdima
      \pgfmathsetlength\@tempdima{\pgf@xa + \pgf@xb}
      \advance \pgf@x by\@tempdima
    \fi
    \ifnum\funprog@function@in=\funprog@function@east
      \pgf@process{\funprog@function@anchor@southwest} \pgf@ya=\pgf@y
      \pgf@process{\funprog@function@anchor@northeast}
      \pgfmathsetlength\pgf@y{.5*(\pgf@y + \pgf@ya)}
      \advance \pgf@x by\pgfkeysvalueof{/funprog/function/port height}
      \pgfkeysgetvalue{/funprog/function/port width}{\pgf@ya}
      \pgfkeysgetvalue{/funprog/function/port separation}{\pgf@yb}
      \pgfkeysgetvalue{/funprog/function/east ports}{\pgf@yc}
      \pgfmathsetlength\@tempdima{\pgf@yc * (\pgf@ya + \pgf@yb)}
      \advance \pgf@y by.5\@tempdima
      \pgfmathsetlength\@tempdima{\pgf@ya / 2 + \pgf@yb / 2}
      \advance \pgf@y by-\@tempdima
      \pgfmathsetlength\@tempdima{\pgf@ya + \pgf@yb}
      \advance \pgf@y by-\@tempdima
    \fi
    \ifnum\funprog@function@in=\funprog@function@west
      \pgf@process{\funprog@function@anchor@northeast} \pgf@ya=\pgf@y
      \pgf@process{\funprog@function@anchor@southwest}
      \pgfmathsetlength\pgf@y{.5*(\pgf@y + \pgf@ya)}
      \advance \pgf@x by-\pgfkeysvalueof{/funprog/function/port height}
      \pgfkeysgetvalue{/funprog/function/port width}{\pgf@ya}
      \pgfkeysgetvalue{/funprog/function/port separation}{\pgf@yb}
      \pgfkeysgetvalue{/funprog/function/west ports}{\pgf@yc}
      \pgfmathsetlength\@tempdima{\pgf@yc * (\pgf@ya + \pgf@yb)}
      \advance \pgf@y by.5\@tempdima
      \pgfmathsetlength\@tempdima{\pgf@ya / 2 + \pgf@yb / 2}
      \advance \pgf@y by-\@tempdima
      \pgfmathsetlength\@tempdima{\pgf@ya + \pgf@yb}
      \advance \pgf@y by-\@tempdima
    \fi
  }

  \savedanchor\out{
    \ifnum\funprog@function@out=\funprog@function@north
      \pgf@process{\funprog@function@anchor@southwest} \pgf@xa=\pgf@x
      \pgf@process{\funprog@function@anchor@northeast}
      \pgfmathsetlength\pgf@x{.5*(\pgf@x + \pgf@xa)}
      \advance \pgf@y by\pgfkeysvalueof{/funprog/function/port height}
    \fi
    \ifnum\funprog@function@out=\funprog@function@south
      \pgf@process{\funprog@function@anchor@northeast} \pgf@xa=\pgf@x
      \pgf@process{\funprog@function@anchor@southwest}
      \pgfmathsetlength\pgf@x{.5*(\pgf@x + \pgf@xa)}
      \advance \pgf@y by-\pgfkeysvalueof{/funprog/function/port height}
    \fi
    \ifnum\funprog@function@out=\funprog@function@east
      \pgf@process{\funprog@function@anchor@southwest} \pgf@ya=\pgf@y
      \pgf@process{\funprog@function@anchor@northeast}
      \pgfmathsetlength\pgf@y{.5*(\pgf@y + \pgf@ya)}
      \advance \pgf@x by\pgfkeysvalueof{/funprog/function/port height}
    \fi
    \ifnum\funprog@function@out=\funprog@function@west
      \pgf@process{\funprog@function@anchor@northeast} \pgf@ya=\pgf@y
      \pgf@process{\funprog@function@anchor@southwest}
      \pgfmathsetlength\pgf@y{.5*(\pgf@y + \pgf@ya)}
      \advance \pgf@x by-\pgfkeysvalueof{/funprog/function/port height}
    \fi
  }

  \savedanchor\centerpoint{%
    \pgf@x = .5\wd\pgfnodeparttextbox
    \pgf@y = .5\ht\pgfnodeparttextbox
  }

  \saveddimen\northportswidth{
    \pgfmathsetlength\pgf@x{\pgfkeysvalueof{/funprog/function/north ports} * (\pgfkeysvalueof{/funprog/function/port width} + \pgfkeysvalueof{/funprog/function/port separation})}
  }

  \saveddimen\southportswidth{
    \pgfmathsetlength\pgf@x{\pgfkeysvalueof{/funprog/function/south ports} * (\pgfkeysvalueof{/funprog/function/port width} + \pgfkeysvalueof{/funprog/function/port separation})}
  }

  \saveddimen\eastportswidth{
    \pgfmathsetlength\pgf@x{\pgfkeysvalueof{/funprog/function/east ports} * (\pgfkeysvalueof{/funprog/function/port width} + \pgfkeysvalueof{/funprog/function/port separation})}
  }

  \saveddimen\westportswidth{
    \pgfmathsetlength\pgf@x{\pgfkeysvalueof{/funprog/function/west ports} * (\pgfkeysvalueof{/funprog/function/port width} + \pgfkeysvalueof{/funprog/function/port separation})}
  }

  \saveddimen\halfportseparation{
    \pgfmathsetlength\pgf@x{.5 * \pgfkeysvalueof{/funprog/function/port separation}}
  }

  \saveddimen\portseparation{
    \pgfmathsetlength\pgf@x{\pgfkeysvalueof{/funprog/function/port separation}}
  }

  \saveddimen\portheight{
    \pgfmathsetlength\pgf@x{\pgfkeysvalueof{/funprog/function/port height}}
  }

  \saveddimen\halfportheight{
    \pgfmathsetlength\pgf@x{.5 * \pgfkeysvalueof{/funprog/function/port height}}
  }

  \saveddimen\portwidth{
    \pgfmathsetlength\pgf@x{\pgfkeysvalueof{/funprog/function/port width}}
  }

  \saveddimen\halfportshadow{
    \pgfmathsetlength\pgf@x{.5 * (\pgfkeysvalueof{/funprog/function/port width} - \pgfkeysvalueof{/funprog/function/port funnel width})}
  }

  \anchor{north excluding ports}{
    \pgf@process{\southwest} \pgf@xa=\pgf@x
    \pgf@process{\northeast}
    \pgfmathsetlength\pgf@x{.5*(\pgf@x + \pgf@xa)}
  }

  \anchor{north}{
    \pgfutil@useanchor{function}{north excluding ports} \pgf@xa=\pgf@x
    \pgf@process{\northeastincludingports}
    \pgf@x=\pgf@xa
  }

  \anchor{south excluding ports}{
    \pgf@process{\northeast} \pgf@xa=\pgf@x
    \pgf@process{\southwest}
    \pgfmathsetlength\pgf@x{.5*(\pgf@x + \pgf@xa)}
  }

  \anchor{south}{
    \pgfutil@useanchor{function}{south excluding ports} \pgf@xa=\pgf@x
    \pgf@process{\southwestincludingports}
    \pgf@x=\pgf@xa
  }

  \anchor{east excluding ports}{
    \pgf@process{\southwest} \pgf@ya=\pgf@y
    \pgf@process{\northeast}
    \pgfmathsetlength\pgf@y{.5*(\pgf@y + \pgf@ya)}
  }

  \anchor{east}{
    \pgfutil@useanchor{function}{east excluding ports} \pgf@ya=\pgf@y
    \pgf@process{\northeastincludingports}
    \pgf@y=\pgf@ya
  }

  \anchor{west excluding ports}{
    \pgf@process{\northeast} \pgf@ya=\pgf@y
    \pgf@process{\southwest}
    \pgfmathsetlength\pgf@y{.5*(\pgf@y + \pgf@ya)}
  }

  \anchor{west}{
    \pgfutil@useanchor{function}{west excluding ports} \pgf@ya=\pgf@y
    \pgf@process{\southwestincludingports}
    \pgf@y=\pgf@ya
  }

  \anchor{in}{
    \firstin
  }

  \anchor{in 1}{
    \firstin
  }

  \anchor{in 2}{
    \secondin
  }

  \anchor{in 3}{
    \pgf@process{\secondin} \pgf@xa=\pgf@x \pgf@ya=\pgf@y
    \pgf@process{\firstin}
    \pgfmathsetlength\pgf@xa{\pgf@xa - \pgf@x}
    \pgfmathsetlength\pgf@ya{\pgf@ya - \pgf@y}
    \pgfmathsetlength\pgf@x{\pgf@x + \pgf@xa * 2}
    \pgfmathsetlength\pgf@y{\pgf@y + \pgf@ya * 2}
  }

  \anchor{in 4}{
    \pgf@process{\secondin} \pgf@xa=\pgf@x \pgf@ya=\pgf@y
    \pgf@process{\firstin}
    \pgfmathsetlength\pgf@xa{\pgf@xa - \pgf@x}
    \pgfmathsetlength\pgf@ya{\pgf@ya - \pgf@y}
    \pgfmathsetlength\pgf@x{\pgf@x + \pgf@xa * 3}
    \pgfmathsetlength\pgf@y{\pgf@y + \pgf@ya * 3}
  }

  \anchor{out}{
    \out
  }

  \backgroundpath{
    \pgf@process{\southwest} \pgf@xa=\pgf@x \pgf@ya=\pgf@y
    \pgf@process{\northeast} \pgf@xb=\pgf@x \pgf@yb=\pgf@y

    % go to the north west corner
    \pgf@xc=\pgf@xa
    \pgf@yc=\pgf@yb
    \pgfpathmoveto{\pgfpoint{\pgf@xc}{\pgf@yc}}

    % go to the beginning of north ports
    \pgfmathsetlength\@tempdima{((\pgf@xb - \pgf@xa) - \northportswidth) / 2}
    \advance\pgf@xc by\@tempdima
    \pgfpathlineto{\pgfpoint{\pgf@xc}{\pgf@yc}}

    % draw the north ports
    \ifnum\pgfkeysvalueof{/funprog/function/north ports}>0
      \foreach \i in {1,...,\pgfkeysvalueof{/funprog/function/north ports}} {
        \pgftransformshift{\pgfpoint{\pgf@xc}{\pgf@yc}}
        {\funprog@function@portpath}
        \pgftransformreset
        \global\advance\pgf@xc by\portseparation
        \global\advance\pgf@xc by\portwidth
      }
    \fi

    % go to the north east corner
    \pgf@xc=\pgf@xb
    \pgfpathlineto{\pgfpoint{\pgf@xc}{\pgf@yc}}

    %go to the beginning of east ports
    \pgfmathsetlength\@tempdima{((\pgf@yb - \pgf@ya) - \eastportswidth) / 2}
    \advance\pgf@yc by-\@tempdima
    \pgfpathlineto{\pgfpoint{\pgf@xc}{\pgf@yc}}

    % draw the east ports
    \ifnum\pgfkeysvalueof{/funprog/function/east ports}>0
      \foreach \i in {1,...,\pgfkeysvalueof{/funprog/function/east ports}} {
        \pgftransformshift{\pgfpoint{\pgf@xc}{\pgf@yc}}
        \pgftransformrotate{-90}
        {\funprog@function@portpath}
        \pgftransformreset
        \global\advance\pgf@yc by-\portseparation
        \global\advance\pgf@yc by-\portwidth
      }
    \fi

    % go to the south east corner
    \pgf@yc=\pgf@ya
    \pgfpathlineto{\pgfpoint{\pgf@xc}{\pgf@yc}}

    % go to the starting of south ports
    \pgfmathsetlength\@tempdima{((\pgf@xb - \pgf@xa) - \southportswidth) / 2}
    \advance\pgf@xc by-\@tempdima
    \pgfpathlineto{\pgfpoint{\pgf@xc}{\pgf@yc}}

    % draw the south ports
    \ifnum\pgfkeysvalueof{/funprog/function/south ports}>0
      \foreach \i in {1,...,\pgfkeysvalueof{/funprog/function/south ports}} {
        \pgftransformshift{\pgfpoint{\pgf@xc}{\pgf@yc}}
        \pgftransformscale{-1}
        {\funprog@function@portpath}
        \pgftransformreset
        \global\advance\pgf@xc by-\portseparation
        \global\advance\pgf@xc by-\portwidth
      }
    \fi

    % go to the south east corner
    \pgf@xc=\pgf@xa
    \pgfpathlineto{\pgfpoint{\pgf@xc}{\pgf@yc}}

    %go to the beginning of west ports
    \pgfmathsetlength\@tempdima{((\pgf@yb - \pgf@ya) - \westportswidth) / 2}
    \advance\pgf@yc by\@tempdima
    \pgfpathlineto{\pgfpoint{\pgf@xc}{\pgf@yc}}

    % draw the east ports
    \ifnum\pgfkeysvalueof{/funprog/function/west ports}>0
    \foreach \i in {1,...,\pgfkeysvalueof{/funprog/function/west ports}} {
      \pgftransformshift{\pgfpoint{\pgf@xc}{\pgf@yc}}
      \pgftransformrotate{90}
      {\funprog@function@portpath}
      \pgftransformreset
      \global\advance\pgf@yc by\portseparation
      \global\advance\pgf@yc by\portwidth
    }
    \fi

    \pgfpathclose
  }
}

\makeatother