learning_fromdocs_minigrep/
lib.rs

1use std::{env, error::Error, fs};
2
3pub struct Config {
4    pub query: String,
5    pub file_name: String,
6    pub case_sensitive: bool,
7}
8impl Config {
9    pub fn new(mut args: std::env::Args) -> Result<Config, &'static str> {
10        args.next();
11
12        let query = match args.next() {
13            Some(arg) => arg,
14            None => return Err("There needs to be two arguments"),
15        };
16
17        let file_name = match args.next() {
18            Some(arg) => arg,
19            None => return Err("There needs to be two arguments"),
20        };
21        let case_sensitive = env::var("CASE_INSENSITIVE").is_err();
22
23        Ok(Config {
24            query,
25            file_name,
26            case_sensitive,
27        })
28    }
29}
30
31pub fn run(config: Config) -> Result<(), Box<dyn Error>> {
32    let contents = fs::read_to_string(&config.file_name)?; //.expect("The file cannot be opened or found.")
33
34    let results = if config.case_sensitive == true {
35        search(&config.query, &contents)
36    } else {
37        search_case_insensitive(&config.query, &contents)
38    };
39
40    for line in results {
41        println!("{}", line);
42    }
43
44    Ok(())
45}
46pub fn search<'a>(query: &str, contents: &'a str) -> Vec<&'a str> {
47    contents.lines().filter(|x| x.contains(query)).collect()
48}
49pub fn search_case_insensitive<'a>(query: &str, contents: &'a str) -> Vec<&'a str> {
50    let query: &str = &query.to_lowercase();
51    contents
52        .lines()
53        .filter(|x| x.to_lowercase().contains(query))
54        .collect()
55}
56
57#[cfg(test)]
58mod tests {
59    use super::*;
60    #[test]
61    fn case_sensitive() {
62        let query = "duct";
63        let contents = "\
64Rust:
65safe, fast, productive.
66Pick three.";
67        assert_eq!(vec!["safe, fast, productive."], search(query, contents));
68    }
69    #[test]
70    fn case_insensitive() {
71        let query = "rUsT";
72        let contents = "\
73Rust:
74safe, fast, productive.
75Pick three.
76Trust me.";
77        assert_eq!(
78            vec!["Rust:", "Trust me."],
79            search_case_insensitive(query, contents)
80        );
81    }
82}
learning_fromdocs_minigrep/lib.rs

learning_fromdocs_minigrep/
lib.rs
