사용 종속성 주입입니다 : 여기
함수의 예입니다. 제네릭과 단사 사상과 커플 링하는 것은, 당신이 어떤 성능 손실되지 않습니다 : IO는 매우 그대로
use std::io::{self, BufRead, Write};
fn prompt<R, W>(mut reader: R, mut writer: W, question: &str) -> String
where
R: BufRead,
W: Write,
{
write!(&mut writer, "{}", question).expect("Unable to write");
let mut s = String::new();
reader.read_line(&mut s).expect("Unable to read");
s
}
#[test]
fn test_with_in_memory() {
let input = b"I'm George";
let mut output = Vec::new();
let answer = prompt(&input[..], &mut output, "Who goes there?");
let output = String::from_utf8(output).expect("Not UTF-8");
assert_eq!("Who goes there?", output);
assert_eq!("I'm George", answer);
}
fn main() {
let stdio = io::stdin();
let input = stdio.lock();
let output = io::stdout();
let answer = prompt(input, output, "Who goes there?");
println!("was: {}", answer);
}
많은 경우를, 당신은 실제로 expect
을 사용하는 대신 호출자까지 오류를 전파 할 것 실패 할 일반적인 장소.
use std::io::{self, BufRead, Write};
struct Quizzer<R, W> {
reader: R,
writer: W,
}
impl<R, W> Quizzer<R, W>
where
R: BufRead,
W: Write,
{
fn prompt(&mut self, question: &str) -> String {
write!(&mut self.writer, "{}", question).expect("Unable to write");
let mut s = String::new();
self.reader.read_line(&mut s).expect("Unable to read");
s
}
}
#[test]
fn test_with_in_memory() {
let input = b"I'm George";
let mut output = Vec::new();
let answer = {
let mut quizzer = Quizzer {
reader: &input[..],
writer: &mut output,
};
quizzer.prompt("Who goes there?")
};
let output = String::from_utf8(output).expect("Not UTF-8");
assert_eq!("Who goes there?", output);
assert_eq!("I'm George", answer);
}
fn main() {
let stdio = io::stdin();
let input = stdio.lock();
let output = io::stdout();
let mut quizzer = Quizzer {
reader: input,
writer: output,
};
let answer = quizzer.prompt("Who goes there?");
println!("was: {}", answer);
}
:
이 방법으로기능을 넘어 확장 될 수있다