anchor.diff:         if element = true. result = true. return. endif.
   
          case element->type.
  -         when lcl_lisp_element=>type_number.
  -           result = element.  "Number evaluates to itself
  +         when lcl_lisp_element=>type_number or lcl_lisp_element=>type_string.
  +           result = element.  "Number or string evaluates to itself
            when lcl_lisp_element=>type_symbol. "Symbol
              result = environment->find( element->value ). "Look up symbol in environment
   
  
positive.code:          data: pchar type char1.
           next_char( ). "Skip past opening quote
           while index < length.
             sval = |{ sval }{ char }|.
             if char = '"' and pchar ne '\'.
               exit.
             endif.
             pchar = char.
             next_char( ).
           endwhile.
  
negative.code:        case element->type.
           when lcl_lisp_element=>type_lambda.
             str = '<lambda>'.
  * TODO: Other Lisp REPLs give back the string as a quoted string
           when lcl_lisp_element=>type_symbol or lcl_lisp_element=>type_string.
             str = element->value.
           when lcl_lisp_element=>type_number.
             str = element->number.
  