anchor.diff:  
   (define (images txt)
    (let ((alt-text {})
  -       (url {} )
  +       (url {})
          (title {})
          (ref-regex    {(!\[(.*?)\][ ]?(?:\n[ ]*)?\[(.*?)\])})
          (inline-regex {(!\[(.*?)\]\([ \t]*<?(\S+?)>?[ \t]*((['"])(.*?)\5[ \t]*)?\))})
  
positive.code:               (replace [text](?<=.)</?code>(?=.)[/text] new-text (HashTable {`}) 0)
                (replace {\*} new-text (HashTable {*}) 0)
                (replace {_} new-text (HashTable {_} ) 0))
                ; 'text
                (if  within-tag-attributes
                     (set 'new-text (last pair))
                     (set 'new-text (encode-backslash-escapes (last pair)))))
          (setf (temp $idx) (list (first pair) new-text)))
    ; return as text
    (join (map last temp))))
  
negative.code:   (replace "{"  s   (HashTable "{") 0)
    (replace {\[} s   (HashTable {[}) 0)
    (replace {\]} s   (HashTable {]}) 0)
    (replace {\\} s   (HashTable "\\") 0))
  
  (define (code-spans s)
    (replace  
  