如何检查字符串是否为有效整数？

Question

Let's say I have

val s = "123"
val r = "a123h"

How do I check if s can be resolved to a valid integer?

Answer 1

The signature of to-int in the package core is

public lostanza defn to-int (s:ref<String>) -> ref<False|Int>

So you need :

defn is-int? (s: String) -> True|False :
  to-int(s) is Int

NB: to-int accepts hexadecimal 0x... , octal 0o... and binary 0b... string representations in addition to decimal ones.