mini_grep_rs/
lib.rs

1use std::{env, fs};
2use std::error::Error;
3
4pub fn run(config: Config) -> Result<(), Box<dyn Error>> {
5    let contents = fs::read_to_string(config.filename)?;
6    let results = if config.case_sensitive {
7        search(&config.query, &contents)
8    } else {
9        search_case_insensitive(&config.query, &contents)
10    };
11    for line in results {
12        println!("Find：{}", line);
13    }
14    Ok(())
15}
16
17pub struct Config {
18    pub query: String,
19    pub filename: String,
20    pub case_sensitive: bool,
21}
22
23impl Config {
24    pub fn new(args: &[String]) -> Result<Config, &'static str> {
25        if args.len() < 3 {
26            return Err("not enough arguments");
27        }
28        let query = args[1].clone();
29        let filename = args[2].clone();
30
31        let case_sensitive = env::var("CASE_INSENSITIVE").is_err();
32        Ok(Config { query, filename, case_sensitive })
33    }
34}
35
36pub fn search<'a>(query: &str, contents: &'a str) -> Vec<&'a str> {
37    let mut results = Vec::new();
38    for line in contents.lines() {
39        if line.contains(query) {
40            results.push(line);
41        }
42    }
43    results
44}
45
46pub fn search_case_insensitive<'a>(query: &str, contents: &'a str) -> Vec<&'a str> {
47    let mut results = Vec::new();
48    let query = query.to_lowercase();
49    for line in contents.lines() {
50        if line.to_lowercase().contains(&query) {
51            results.push(line);
52        }
53    }
54    results
55}
56
57#[cfg(test)]
58mod tests {
59    use crate::{search, search_case_insensitive};
60
61    #[test]
62    fn case_sensitive() {
63        let query = "duct";
64        let contents = "
65Rust:
66safe, fast, productive.
67Pick three.
68Duct tape.";
69        assert_eq!(vec!["safe, fast, productive."], search(query, contents));
70    }
71
72    #[test]
73    fn case_insensitive() {
74        let query = "rUsT";
75        let contents = "
76Rust:
77safe, fast, productive.
78Pick three.
79Trust me.";
80        assert_eq!(vec!["Rust:", "Trust me."], search_case_insensitive(query, contents));
81    }
82}
mini_grep_rs/lib.rs

mini_grep_rs/
lib.rs
