Added virtual-sequence sequence-view, which is a MVC view on the underlying sequence

For now untyped, but the intention is to use the typed version when all conflicts are resolvable.

diff --git a/core/sequences/sequences.factor b/core/sequences/sequences.factor
index 041a9354157dc5ed1309866d24dad5afaeb1eabe..c633f2e0cb207a2e1916548f9b040554accf383e 100644 (file)
--- a/core/sequences/sequences.factor
+++ b/core/sequences/sequences.factor
@@ -209,6 +209,14 @@ M: virtual-sequence new-sequence virtual-exemplar new-sequence ; inline
 
 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 } ;