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