如何向hashmap值的向量追加?
use std::collections::HashMap;
fn main() {
let mut dict = HashMap::new();
let mut prefix = ["", ""];
let lorem = "Lorem ipsum dolor sit amet, consectetur adipisicing elit. Eum debitis earum quidem dolorem quos consequatur perspiciatis architecto! Reiciendis rem est blanditiis fugiat quidem similique suscipit soluta, ab veniam, laborum numquam. Lorem ipsum dolor sit amet, consectetur adipisicing elit. Eum debitis earum quidem dolorem quos consequatur perspiciatis architecto! Reiciendis rem est blanditiis fugiat quidem similique suscipit soluta, ab veniam, laborum numquam.";
for token in lorem.split_whitespace() {
if prefix[0] != "" {
let key = prefix.join(" ");
if !dict.contains_key(&key) {
dict.insert(key, vec![token]);
} else {
let v = dict.get(&key);
v.push(token); // does not actually return a vector
}
}
prefix[0] = prefix[1];
prefix[1] = token;
}
}
问题是行let v = dict.get(&key);
通常我希望能够推到向量上,但它似乎返回某种集合,我不确定如何附加到它.