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use std::error::Error;
use std::fs;
use std::env;
pub struct Config{
pub query:String,
pub file_name: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 file_name = 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,file_name,case_sensitive})
}
}
pub fn run(config:Config) -> Result<(),Box<dyn Error>>{
let contents = fs::read_to_string(config.file_name)?;
let results = if config.case_sensitive {
search(&config.query, &contents)
}else{
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(|a|a.contains(query)).collect()
}
pub fn search_case_insensitive<'a>(query:&str,contents:&'a str)
-> Vec<&'a str>{
contents.lines().filter(|a|a.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));
}
}