src/doc/book/listings/ch12-an-io-project/listing-12-18/src/lib.rs

   1 use std::error::Error;
   2 use std::fs;
   3
   4 pub struct Config {
   5     pub query: String,
   6     pub file_path: String,
   7 }
   8
   9 impl Config {
  10     pub fn build(args: &[String]) -> Result<Config, &'static str> {
  11         if args.len() < 3 {
  12             return Err("not enough arguments");
  13         }
  14
  15         let query = args[1].clone();
  16         let file_path = args[2].clone();
  17
  18         Ok(Config { query, file_path })
  19     }
  20 }
  21
  22 pub fn run(config: Config) -> Result<(), Box<dyn Error>> {
  23     let contents = fs::read_to_string(config.file_path)?;
  24
  25     Ok(())
  26 }
  27
  28 // ANCHOR: here
  29 pub fn search<'a>(query: &str, contents: &'a str) -> Vec<&'a str> {
  30     for line in contents.lines() {
  31         if line.contains(query) {
  32             // do something with line
  33         }
  34     }
  35 }
  36 // ANCHOR_END: here
  37
  38 #[cfg(test)]
  39 mod tests {
  40     use super::*;
  41
  42     #[test]
  43     fn one_result() {
  44         let query = "duct";
  45         let contents = "\
  46 Rust:
  47 safe, fast, productive.
  48 Pick three.";
  49
  50         assert_eq!(vec!["safe, fast, productive."], search(query, contents));
  51     }
  52 }