In article <1037846576.443738.8662.nullmailer / picachu.netlab.jp>, Yukihiro
Matsumoto wrote:
>Hi,
>
>In message "O() notation for Arrays operations and why is there no List class"
>    on 02/11/21, MetalOne <jcb / iteris.com> writes:
>|Why is there no List class?
>
>Because it is easily defined by users.
[...]

Additionally, since the currently Ruby implementation is not properly
tail-recursive, generating lists with recursive functions is not efficient,
hence using << to add elements to an Array is more appropriate.