Question

是否有更清洁的方法这样做? I m 试图做到配对模式

<代码>(备选案文*>)

the only way I found was doing this :

match a with
| _, l -> match !l with
  | (c, n)::t -> doSomething

Wouldn t there be a way to match a with something else like ...

match a with
| _, ref (c,n)::t -> doSomething

......或某种类似情况? 在这种例子中,它看上去做的是很强的,而实际上它可能有些是......。

Thanks for your answers.

Answer 1

www.un.org/Depts/DGACM/index_french.htm 类型的定义是具有变性领域的记录:

type  a ref = {
    mutable contents :  a;
}

This means that you can pattern match against it using record syntax like this:

match a with
| _, { contents = (c,n)::t } -> doSomething

Answer 2

In OCaml a ref is secretly a record with a mutable field named contents.

match a with
| _, { contents = (c, n) :: t } -> (* Do something *)