use std::fs::File;
use std::io::prelude::*;
use std::error::Error;
use std::env;
pub fn add_one(x: i32) -> i32 {
x + 1
}
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 contents = String::new();
f.read_to_string(&mut contents)?;
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(|x| x.contains(query)).collect()
}
pub fn search_case_insensitive<'a>(query:&str, contents:&'a str) -> Vec<&'a str> {
let query = query.to_lowercase();
let mut results = Vec::new();
for line in contents.lines() {
if line.to_lowercase().contains(&query) {
results.push(line);
}
}
results
}
#[cfg(test)]
mod test {
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)
)
}
}