INSTANCE: virtual-sequence sequence
+! TUPLE: sequence-view { seq sequence read-only } ;
+TUPLE: sequence-view { seq read-only } ;
+INSTANCE: sequence-view virtual-sequence
+
+M: sequence-view virtual-exemplar seq>> ; inline
+M: sequence-view virtual@ seq>> ; inline
+M: sequence-view length seq>> length ; inline
+
! A reversal of an underlying sequence.
TUPLE: reversed { seq read-only } ;