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use std::{env, error::Error, fs}; pub struct Config { pub query: String, pub filename: String, pub case_sensitive: bool, } impl Config { pub fn new(mut args: env::Args) -> Result<Config, &'static str> { args.next(); let query = match args.next() { Some(arg) => arg, None => return Err("Didn't get a query string"), }; let filename = match args.next() { Some(arg) => arg, None => return Err("Didn't get a file name"), }; let case_sensitive = match args.next() { Some(arg) => match arg.as_str() { "y" => true, _ => false, }, _ => false, }; Ok(Config { query, filename, case_sensitive, }) } } pub fn run(config: Config) -> Result<(), Box<dyn Error>> { let contents = fs::read_to_string(config.filename)?; let results = match config.case_sensitive { true => search(&config.query, &contents), false => search_case_insensitive(&config.query, &contents), }; for line in results { println!("{}", line); } Ok(()) } pub fn search<'a>(query: &str, contents: &'a str) -> Vec<&'a str> { contents .lines() .filter(|line| line.contains(query)) .collect() } pub fn search_case_insensitive<'a>(query: &str, contents: &'a str) -> Vec<&'a str> { contents .lines() .filter(|line| line.to_lowercase().contains(&query.to_lowercase())) .collect() } #[cfg(test)] mod tests { use super::*; #[test] fn case_sensitive() { let query = "duct"; let contents = "\ Rust: safe, fast, productive. Pick three. Duct tape."; assert_eq!(vec!["safe, fast, productive."], search(query, contents)); } #[test] fn case_insensitive() { let query = "rUsT"; let contents = "\ Rust: safe, fast, productive. Pick three. Trust me."; assert_eq!( vec!["Rust:", "Trust me."], search_case_insensitive(query, contents) ); } }