anchor.diff:  
      PRETTY-PRINTER CONTROL
   
  -   %< and %> the formatting inside is wrapped into PPRINT-LOGICAL-BLOCK
  -   %> and %< opposite pair, *PPRINT-PRETTY* is unbound inside
  +   %< and %> the formatting inside is wrapped into
  +   PPRINT-LOGICAL-BLOCK, the value of *PRINT-PRETTY* is not changed.
  +
  +   The colon flag %:< %> in addition to wrapping whats inside in
  +   PPRINT-LOGICAL-BLOCK will also bind *PRINT-PRETTY* to T
  +
  +   %> and %< is the opposite pair, *PPRINT-PRETTY* is unbound inside
   
      %_ conditional newline, issues (PPRINT-NEWLINE :linear)
      %:_ conditional newline, issues (PPRINT-NEWLINE :fill)
  
positive.code:                          (compile-pattern-format pattern idx stopchar)
                         (setq idx newidx)
                         (add-formatter (lambda (stream fmt-info logger level log-func)
                                          (funcall formatter stream fmt-info logger level log-func wrap))))))
                 (setq state :normal
                       minlen 0
                       maxlen nil
  
negative.code: 
  (define-pattern-formatter (#\< #\>)
    "Wrap content inside into PPRINT-LOGICAL-BLOCK"
    (pprint-logical-block (stream nil)
      (if (format-empty-skip fmt-info) 
          (let ((*print-pretty* t)) 
            (funcall wrap stream logger log-level log-func))
          (funcall wrap stream logger log-level log-func))))
  
  (define-pattern-formatter (#\> #\<)
    "Wrap content inside with *PRINT-PRETTY* bound to NIL"
  