ary) pattern to switch between the following
-- two patterns. The resulting structure comes from the source patterns, not the
-- binary pattern. See also @stitch@.
sew :: Pattern Bool -> Pattern a -> Pattern a -> Pattern a
sew pb a b = overlay (mask pb a) (mask (inv pb) b)

-- | Uses the first (b
sew :: Pattern Bool -> Pattern a -> Pattern a -> Pattern a
sew pb a b = overlay (mask pb a) (mask (inv pb) b)
sew pb a b = overlay (mask pb a) (mask (inv pb) b)