minigrep.rs/src/lib.rs

101 行
1.9 KiB
Rust

use std::fs;
//use std::fs::File;
//use std::io::prelude::*;
use std::error::Error;
use std::env;
pub struct Config {
query: String,
filename: String,
insensitive: bool,
}
pub fn run(conf: Config) -> Result<(), Box<dyn Error>> {
let contents = fs::read_to_string(conf.filename)?;
let results = if conf.insensitive {
search(&conf.query, &contents)
} else {
search_insensitive(&conf.query, &contents)
};
for line in results {
println!("{}", line);
}
Ok(())
}
fn search<'a>(query: &str, contents: &'a str) -> Vec<&'a str> {
let mut results = Vec::new();
for line in contents.lines() {
if line.contains(query) {
results.push(line);
}
}
results
}
fn search_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
}
impl Config {
pub fn new(args: &[String]) -> Result<Config, &'static str> {
if args.len() < 3 {
return Err("too few arguments")
}
Ok(Config {
query: args[1].clone(),
filename: args[2].clone(),
insensitive: env::var("CASE_INSENSITIVE").is_err(),
})
}
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn case_sensitive() {
let query = "duct";
let contents = "\
Rust:
safe, fast, productive.
Pick three.";
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_insensitive(query, contents)
);
}
}