Immutable List
The immutable list resides in the package @list
.
It is either:
Empty
: an empty listMore
: an element and the rest of the list.
You can construct @list.T
using @list.empty()
and @list.construct(..)
. You can also use xs.prepend(x)
to prepend element to the front of list.
fn[A] count(list : @list.T[A]) -> UInt {
match list {
Empty => 0
More(_, tail~) => count(tail) + 1
}
}
///|
fn main {
let empty_list = @list.empty()
let list_1 = @list.construct(1, empty_list)
let list_2 = list_1.prepend(2)
let list_3 = empty_list.prepend(3)
let reversed_1 = list_1.rev()
let n = count(reversed_1)
}