rust_sample_rtx 0.1.0

A sample for lifetimes


// lib.rs for mod reading_file_and_printing
use std::error::Error;
use std::fs;
use std::env;

pub struct Config {
    pub query: String,
    pub filename: String,
    pub case_sensitive: bool
}

impl Config {
    pub fn new(args: &[String]) -> Result<Config, &str> {
        if args.len() < 3 {
            return Err("not enough arguments");
        }

        let query = args[1].clone();
        let filename = args[2].clone();
        let case_sensitive = env::var("CASE_INSENSITIVE").is_err();

        Ok(Config { query, filename, case_sensitive })
    }
}

pub fn run(config: Config) -> Result<(), Box<dyn Error>> {
    let contents = fs::read_to_string(config.filename)?;

    let results = if config.case_sensitive {
        search(&config.query, &contents)
    } else {
        search_case_insensitive(&config.query, &contents)
    };

    for line in results {
        println!("{}", line);
    }

    Ok(())
}

/// This is a sample `struct`.
/// It has one field called `count`.
pub 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_case_insensitive<'a>(query: &str, contents: &'a str) -> Vec<&'a str> {

    let query = query.to_lowercase();
    let mut result = Vec::new();

    for line in contents.lines(){
        if line.to_lowercase().contains(&query){
            result.push(line)
        }

    }

    result
}

#[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)
        );
    }
}

/// Adds one to the number given.
///
/// # Examples
///
/// ```
/// let arg = 5;
/// let answer = rust_sample::add_one(arg);
///
/// assert_eq!(6, answer);
/// ```
pub fn add_one(x: i32) -> i32 {
    x + 1
}

// Add this to main.rs for running minigrep

// fn main() {
//     let args: Vec<String> = env::args().collect();
//
//     let config = Config::new(&args).unwrap_or_else(|err| {
//         eprintln!("Problem parsing arguments: {}", err);
//         process::exit(1);
//     });
//
//     // println!("Searching for {}", config.query);
//     // println!("In file {}", config.filename);
//
//     if let Err(e) = rust_sample::run(config) {
//         eprintln!("Application error: {}", e);
//
//         process::exit(1);
//     }
// }