trees

• The inner beauty of tree traversals (in Haskell) – January 26, 2012
• Directory-tree printing in Haskell, part three: lazy I/O – March 28, 2007
• Directory-tree printing in Haskell, part two: refactoring – March 7, 2007
• A simple directory-tree printer in Haskell – February 22, 2007