[Haskell-cafe] Record updates

Haskell's record syntax is quite nice, for a number of reasons. However, suppose I have some record: data Foobar = Foobar {foo1, foo2, foo3...} Now suppose that foo3 :: [Int], and I want to prepend 5 to it. I end up having to write something like let v1 = v0 {foo3 = 5 : (foo3 v0)} If the field name isn't "foo" but something more descriptive, and the transformation to be applied to it is more intricate, you end up with quite a bit of code. In summary, record syntax gives you a nice way of replacing the value of one field with something else, but no easy way to *modify* the existing value somehow. Does anybody know of a way around this? Is there some trick I'm not seeing? Is there an extension or proposal that fixes this?