1
我不是真的在List.rev和空列表[]
None -> List.rev is
和None -> []
let try_parse parse x = try Some (parse x) with Error _ -> None;;
let parse_list parse =
let rec aux is = function
| [] -> List.rev is, []
| (hd :: tl) as xs ->
match try_parse parse hd with
| Some i -> aux (i::is) tl
| None -> List.rev is, xs
in aux [];;
和
let parse_list parse =
let rec aux is = function
| [] -> List.rev is, []
| (hd :: tl) as xs ->
match try_parse parse hd with
| Some i -> aux (i::is) tl
| None -> [], xs
in aux [];;
它们是不同的理解有关的函数(parse_list
)?如果他们不同,请给我一个例子吗?非常感谢