extending "list" in S4: loss of element names

using R 2.3 of 1/31/06

new("list")

list()

new("list", list(a=1))

$a
[1] 1

setClass("listlike", contains="list")

[1] "listlike"

new("listlike", list(a=1))

An object of class "listlike"
[[1]]
[1] 1

Why does the list in the second construction lose
the element name?  A workaround is to endow the
listlike class with a names slot, but it would
be nice for the names to be propagated from the
data to the object.

Loss of names in a numeric construction does
not require extension:

new("numeric", c(a=1))

[1] 1

But coercion can allow names to persist.

as(c(a=1), "numeric")

a
1