   STRING
   ~~~~~~
      { { literal-1    } [ DELIMITED BY { SIZE         } ] }...
        { identifier-1 }   ~~~~~~~~~    { ~~~~         }
                                        { literal-2    }
                                        { identifier-2 }
        INTO identifier-3
        ~~~~
      [ WITH POINTER identifier-4 ]
             ~~~~~~~
      [ ON OVERFLOW imperative-statement-1 ]
           ~~~~~~~~
      [ NOT ON OVERFLOW imperative-statement-2 ]
        ~~~    ~~~~~~~~
 [ END-STRING ]
   ~~~~~~~~~~
