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use std::error::Error; use std::fs::File; use std::io::prelude::*; use std::env; pub struct Config { pub query: String, pub filename: String, pub case_sensitive: bool, } impl Config { pub fn new(mut args: std::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 = env::var("CASE_INSENSITIVE").is_err(); Ok(Config { query, filename, case_sensitive}) } } pub fn run(config: Config) -> Result<(), Box<Error>> { let mut f = File::open(config.filename)?; let mut s = String::new(); f.read_to_string(&mut s)?; let results = if config.case_sensitive { search(&config.query, &s) } else { search_case_insensitive(&config.query, &s) }; 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> { let query = query.to_lowercase(); let mut res = Vec::new(); for line in contents.lines() { if line.to_lowercase().contains(&query) { res.push(line); } } res } #[cfg(test)] mod test { use super::*; #[test] fn one_result() { let query = "duct"; let contents = "\ Rust: safe, fast, productive pick three. Duck 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) ) } }