chaogrep/
lib.rs

1use std::env;
2use std::error::Error;
3use std::fs;
4
5pub struct Config {
6    pub query: String,
7    pub file_path: String,
8    pub ignore_case: bool,
9}
10
11impl Config {
12    pub fn build(mut args: impl Iterator<Item = String>) -> Result<Config, &'static str> {
13        args.next();
14        let query = match args.next() {
15            Some(arg) => arg,
16            None => return Err("Didn't get a query string"),
17        };
18        let file_path = match args.next() {
19            Some(arg) => arg,
20            None => return Err("Didn't get a file path"),
21        };
22
23        let ignore_case = env::var("IGNORE_CASE").is_ok();
24        Ok(Config {
25            query,
26            file_path,
27            ignore_case: ignore_case,
28        })
29    }
30}
31
32pub fn run(config: Config) -> Result<(), Box<dyn Error>> {
33    println!(
34        "Searching for `{}` in file ``{}:",
35        config.query, config.file_path
36    );
37    let contents = fs::read_to_string(config.file_path)?;
38    let res;
39    if config.ignore_case {
40        res = search_case_insensitive(&config.query, &contents);
41    } else {
42        res = search(&config.query, &contents);
43    }
44    for line in res {
45        println!("{line}")
46    }
47    Ok(())
48}
49
50pub fn search<'a>(query: &str, contents: &'a str) -> Vec<&'a str> {
51    contents
52        .lines()
53        .filter(|line| line.contains(query))
54        .collect()
55}
56
57pub fn search_case_insensitive<'a>(query: &str, contents: &'a str) -> Vec<&'a str> {
58    let mut res = Vec::new();
59    let query = &query.to_lowercase();
60    for line in contents.lines() {
61        if line.to_lowercase().contains(query) {
62            res.push(line)
63        }
64    }
65
66    res
67}
68
69#[cfg(test)]
70mod tests {
71    use super::*;
72
73    #[test]
74    fn one_reault() {
75        let query = "duct";
76        let contents = "\
77Rust:
78safe, fast, productive.
79Pick three.";
80
81        assert_eq!(vec!["safe, fast, productive."], search(query, contents));
82    }
83
84    #[test]
85    fn case_sensitive() {
86        let query = "duct";
87        let contents = "\
88Rust:
89safe, fast, productive.
90Pick three.
91Duct tape.";
92
93        assert_eq!(vec!["safe, fast, productive."], search(query, contents));
94    }
95
96    #[test]
97    fn case_insensitive() {
98        let query = "ruSt";
99        let contents = "\
100Rust:
101safe, fast, productive.
102Pick three.
103Trust me.";
104
105        assert_eq!(
106            vec!["Rust:", "Trust me."],
107            search_case_insensitive(query, contents)
108        )
109    }
110}
chaogrep/lib.rs

chaogrep/
lib.rs
