在Rust中,您可以在迭代器上循环。例如:
fn main() {
for i in (1..4).cycle().take(5) {
print!("{} ", i);
}
}
输出继电器:
1 2 3 1 2
如何在F#中做同样的事情?
[<EntryPoint>]
let main argv =
seq { 1 .. 4 } |> (* Something *) |> Seq.take 5 |> Seq.iter (printf "%d ")
0
答案 0 :(得分:7)
我不知道任何内置函数,但您可以轻松创建自己的函数:
let cycle items = seq {
while true do
yield! items
}
或
let cycle' items =
Seq.initInfinite (fun _ -> items) |> Seq.concat
或
let rec cycle'' items = seq {
yield! items
yield! cycle'' items
}
然后
// 1 2 3 1 2
seq { 1 .. 3 } |> cycle |> Seq.take 5 |> Seq.iter (printf "%d ")