如何在Rust中计算正则表达式匹配？

Question

I'd like to count the matches of a regex in a string with Rust. I managed to print all matches:

let re = Regex::new(r"(?i)foo").unwrap();
let result = re.find_iter("This is foo and FOO foo as well as FoO.");
for i in result {
    println!("{}", i.as_str())
}

But I fail to simply get the number of matches. I can't find any function that gives me the count. I also tried size_hint() , but that does not work as well. Any way I can do that?

Here is the Scala version of what I'm looking for.

Answer 1

你已经有了迭代器，所以只计算迭代器中的元素数量：

re.find_iter("This is foo and FOO foo as well as FoO.").count()