minigrep_dalingtao/
lib.rs

1//!
2//! This mod implement grep main logic
3//! 
4
5use std::fs;
6use std::error::Error;
7
8pub struct Config<'a> {
9    pattern: &'a String, 
10    filename: &'a String,
11}
12
13#[derive(Debug)]
14#[derive(PartialEq)]
15pub struct Row {
16    row: String,
17    row_num: usize
18}
19
20impl Row {
21    pub fn new(row: String, row_num: usize) -> Self {
22        Row{row, row_num}
23    }
24}
25impl ToString for Row {
26    fn to_string(&self) -> String {
27        format!("{} : {}", self.row_num, self.row)
28    }
29}
30
31impl<'a> Config<'a> {
32    pub fn new(pattern: &'a String, filename: &'a String) -> Self {
33        Config { pattern, filename }
34    }
35}
36
37pub fn run(config: Config) -> Result<(), Box<dyn Error>> {
38    let contents = dbg!(fs::read_to_string(config.filename)?);
39    let rows = filter(config.pattern, &contents);
40    for row in rows.iter() {
41        println!("{}", row.to_string());
42    }
43    Ok(())
44}
45
46///
47/// process content and filter out all the rows with specified pattern
48/// 
49/// # Examples
50/// 
51/// ```
52/// let ans = minigrep_dalingtao::filter(&"123".to_string(), &"123\r\n456".to_string());
53/// assert_eq!(vec![minigrep_dalingtao::Row::new("123".to_string(), 0)], ans);
54/// ```
55/// 
56pub fn filter(pattern: &String, content: &String) -> Vec<Row> {
57    let res: Vec<Row> = content.split("\r\n").enumerate().filter(|(index, row)| {
58        row.contains(pattern)
59    })
60    .map(|(index, row)| { Row::new(row.to_string(), index) })
61    .collect();
62    res
63}
64
65#[cfg(test)]
66mod tests {
67    use super::*;
68
69    #[test]
70    fn filter_test() {
71        let ret = filter(&"human".to_string(), &"I'm a human\r\nI will never die".to_string());
72        assert_eq!(ret, vec![Row{row_num: 0, row: "I'm a human".to_string()}]);
73    }
74}
minigrep_dalingtao/lib.rs

minigrep_dalingtao/
lib.rs
