anchor.diff:                  (delimit))
   
                  ((handle-extensible-syntax context readtable)
  -                (again))
  -
  -               ;; If the current character is backslash, single-quote,
  -               ;; or double-quote ( '\', '", or ' )' and it is not
  -               ;; quoted, it shall affect quoting for subsequent
  -               ;; characters up to the end of the quoted text. The rules
  -               ;; for quoting are as described in Quoting. During token
  -               ;; recognition no substitutions shall be actually
  -               ;; performed, and the result token shall contain exactly
  -               ;; the characters that appear in the input (except for
  -               ;; <newline> joining), unmodified, including any embedded
  -               ;; or enclosing quotes or substitution operators, between
  -               ;; the quote mark and the end of the quoted text. The
  -               ;; token shall not be delimited by the end of the quoted
  -               ;; field.
  -               ((equal (next-char) #\")
  -                (lexer-context-add-part context (read-double-quote stream))
                   (again))
   
                  ;; If the current character is an unquoted '$' or '`',
  
positive.code:   (lexer-context-consume-character context)
    t)
  
  (define-once-global +standard-shell-readtable+
      (as-> *empty-shell-readtable* x
        (with-handler x "'" 'handle-quote)
        (with-handler x "\\" 'handle-backslash)))
  
  (defun token-iterator (stream &key (readtable +standard-shell-readtable+))
    (make-iterator ()
  
negative.code:         (parts (make-extensible-vector :element-type 'token))
          (literal-string (make-extensible-vector :element-type 'character))
          (next-char (peek-char nil stream nil :eof)))
      (labels ((keep ()
                 (vector-push-extend next-char literal-string)
                 (skip))
  