use std::env; use std::error::Error; use std::fs; pub struct Config { pub query: String, pub filename: String, pub case_sensitive: bool, } impl Config { pub fn new(mut args: std::env::Args) -> Result { 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 filename"), }; let case_sensitive = env::var("CASE_INSENSITIVE").is_err(); Ok(Config { query, filename, case_sensitive }) } } pub fn run(config: Config) -> Result<(), Box> { let contents = fs::read_to_string(config.filename)?; let results = if config.case_sensitive { search(&config.query, &contents) } else { search_case_insensitive(&config.query, &contents) }; for line in results { println!("{}", line); } Ok(()) } fn search<'a>(query: &str, contents: &'a str) -> Vec<&'a str> { contents.lines() .filter(|line| line.contains(query)) .collect() } 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) ); } }