NystromDungeon.xml

<sequence values="BPWRG" origin="True">
  <all in="PBB" out="**P" comment="draw a grid"/>
  <one in="PBPBPBPBP/BBBBBBBBB/PBPBPBPBP/BBBBBBBBB/PBPBPBPBP/BBBBBBBBB/PBPBPBPBP" out="WWWWWWWWW/WWWWWWWWW/WWWWWWWWW/WWWWWWWWW/WWWWWWWWW/WWWWWWWWW/WWWWWWWWW"/>
  <markov comment="generate corridors with MazeBacktracker">
    <one in="RBP" out="GGR"/>
    <one in="GGR" out="RWW"/>
    <one in="P" out="R"/>
  </markov>
  <one in="R" out="G" steps="1" comment="leave only one start"/>
  <all in="R" out="W" comment="forget other starts"/>
  <markov comment="connect components">
    <all in="GWW" out="**G"/>
    <one in="GBW" out="*WG"/>
  </markov>
  <one in="GBG" out="*W*" steps="5" comment="insert cycles"/>
  <!--<one in="WGBG/WW**" out="**W*/****" steps="5"/>-->
  <all in="G" out="W" comment="forget structure"/>
  <all in="BBB/BWB" out="BBB/BBB" comment="retract dead ends"/>
</sequence>

<!--
Generates a dungeon with rooms and corridors, containing a fixed amount of cycles.

Adaptation of http://journal.stuffwithstuff.com/2014/12/21/rooms-and-mazes/
Compare to implementations in conventional languages: https://github.com/munificent/rooms-and-mazes

For shorter versions that use connectivity patterns, see NystromKruskal and KruskalNystrom.
-->