zzq_minigrep/

lib.rs

//! # Minigrep
//!
//! `minigrep` 是用来在文件中查找相关字符串的工具类

use std::{env, fs};
use std::error::Error;


/// 根据配置参数信息运行，查找文件里面的文本和query一致的信息
///
/// # Examples
///
/// ```
/// use std::process;
/// use std::env;
/// use zzq_minigrep::Config;
/// let config =Config::build(env::args()).unwrap_or_else(|err| {
///         // println!("参数解析错误：{err}");
///         eprintln!("参数解析错误：{err}");
///         process::exit(1);
///     });
/// if let Err(e) = zzq_minigrep::run(config) {
///         // println!("Application error: {e}");
///         eprintln!("Application error: {e}");
///         process::exit(1);
///     }
/// ```
pub fn run(config: Config) -> Result<(), Box<dyn Error>> {
    let contents = fs::read_to_string(config.file_path)?;
    // println!("\nWith text:\n{contents}");

    // for line in search(&config.query, &contents) {
    //     println!("{line}");
    // }
    let results = if config.ignore_case {
        search_case_insensitive(&config.query, &contents)
    } else {
        search(&config.query, &contents)
    };
    for line in results {
        println!("{line}");
    }
    Ok(())
}

fn parse_config2(args: &[String]) -> (&str, &str) {
    let query = &args[1];
    let file_path = &args[2];
    (query, file_path)
}

/// 输入配置实体类
///
pub struct Config {
    pub query: String,
    pub file_path: String,
    pub ignore_case: bool,
}

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

impl Config {
    //=======v1
    // fn new(args: &[String]) -> Config {
    //     if args.len() < 3 {
    //         panic!("参数不足，请输入查询关键词和文件名称，比如:\r\n minigrep test filename.txt")
    //     }
    //     let query = args[1].clone();
    //     let file_path = args[2].clone();
    //     Config { query, file_path }
    // }
    ////=======v2
    // pub fn build(args: &[String]) -> Result<Config, &'static str> {
    //     if args.len() < 3 {
    //         // panic!("")
    //         return Err("参数不足，请输入查询关键词和文件名称，比如:\r\n minigrep test filename.txt");
    //     }
    //     let query = args[1].clone();
    //     let file_path = args[2].clone();
    //     let ignore_case = env::var("IGNORE_CASE").is_ok();
    //     Ok(Config { query, file_path, ignore_case  })
    // }
    ////=======v3
    /// 根据输入参数来构造配置实体信息
    /// 第一个参数是查询的文本信息
    /// 第二个参数是文件信息
    /// 具体为：minigrep test test.txt
    pub fn build(mut args: impl Iterator<Item=String>) -> Result<Config, &'static str> {
        args.next();
        let query = match args.next() {
            Some(arg) => arg,
            None => return Err("没有查询参数，请输入查询字符串……")
        };
        let file_path = match args.next() {
            Some(arg) => arg,
            None => return Err("没有输入文件地址参数")
        };
        let ignore_case = env::var("IGNORE_CASE").is_ok();

        Ok(Config {
            query,
            file_path,
            ignore_case,
        })
    }
}

// fn parse_config(args: &[String]) -> Config {
//     Config::new(&args)
// }

/// Iterate through each line of the contents.
///Check whether the line contains our query string.
/// If it does, add it to the list of values we’re returning.
/// If it doesn’t, do nothing.
/// Return the list of results that match.
// pub fn search(query: &str, contents: &str) -> Vec<&str> {// expect a named lifetime parameter
pub fn search<'a>(query: &str, contents: &'a str) -> Vec<&'a str> {
    ////=======v1
    // let mut results = vec![];
    // for line in contents.lines() {
    //     if line.contains(query) {
    //         results.push(line);
    //     }
    // }
    // results

    ////=======v2
    // let mut results = Vec::new();
    contents.lines().filter(|line| line.contains(query)).collect()
    // results
}

///大小写敏感搜索
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 tests {
    use super::*;

    #[test]
    fn one_result() {
        let query = "我";
        let contents = "\
        这是一个我
s是一个还可以的rust学习者,
天下无双
        ";
        assert_eq!(vec!["这是一个我"], search(query, contents));
    }

    #[test]
    fn one_result_2() {
        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_case_insensitive(query, contents)
        );
    }
}