anchor.diff:  
   (define (images txt)
    (let ((alt-text {})
  -       (url {} )
  +       (url {})
          (title {})
          (ref-regex    {(!\[(.*?)\][ ]?(?:\n[ ]*)?\[(.*?)\])})
          (inline-regex {(!\[(.*?)\]\([ \t]*<?(\S+?)>?[ \t]*((['"])(.*?)\5[ \t]*)?\))})
  
positive.code:    (println (markdown (join *stdin* "\n")))
     (exit))
  [/text]
  ; eof
negative.code:   (replace "{"  s   (HashTable "{") 0)
    (replace {\[} s   (HashTable {[}) 0)
    (replace {\]} s   (HashTable {]}) 0)
    (replace {\\} s   (HashTable "\\") 0))
  
  (define (code-spans s)
    (replace  
  