minigrep

the mini grep implementation from chapter 12 of "the rust programming language"
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commit 46ac7ea23a9614a85df30fcebacf3f10c7e1a060
Author: Chris Johns <chris@ter0.net>
Date:   Tue, 28 Apr 2020 15:37:00 +0100

Initial commit

Diffstat:
A.gitignore | 1+
ACargo.lock | 5+++++
ACargo.toml | 9+++++++++
Apoem.txt | 10++++++++++
Asrc/lib.rs | 101+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Asrc/main.rs | 16++++++++++++++++
6 files changed, 142 insertions(+), 0 deletions(-)

diff --git a/.gitignore b/.gitignore @@ -0,0 +1 @@ +/target diff --git a/Cargo.lock b/Cargo.lock @@ -0,0 +1,5 @@ +# This file is automatically @generated by Cargo. +# It is not intended for manual editing. +[[package]] +name = "minigrep" +version = "0.1.0" diff --git a/Cargo.toml b/Cargo.toml @@ -0,0 +1,9 @@ +[package] +name = "minigrep" +version = "0.1.0" +authors = ["Chris Johns <chris@ter0.net>"] +edition = "2018" + +# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html + +[dependencies] diff --git a/poem.txt b/poem.txt @@ -0,0 +1,10 @@ +I’m nobody! Who are you? +Are you nobody, too? +Then there’s a pair of us - don’t tell! +They’d banish us, you know. + +How dreary to be somebody! +How public, like a frog +To tell your name the livelong day +To an admiring bog! + diff --git a/src/lib.rs b/src/lib.rs @@ -0,0 +1,101 @@ +use std::env; +use std::error::Error; +use std::fs; + +pub struct Config { + pub query: String, + pub filename: String, + pub case_sensitive: bool, +} + +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(()) +} + +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 +} + +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 +} + +impl Config { + pub fn new(args: &[String]) -> Result<Config, &'static 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, + }) + } +} + +#[cfg(test)] +mod tests { + use super::*; + + #[test] + fn one_result() { + 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) + ); + } +} diff --git a/src/main.rs b/src/main.rs @@ -0,0 +1,16 @@ +use minigrep::Config; +use std::env; +use std::process; + +fn main() { + let args: Vec<String> = env::args().collect(); + let config = Config::new(&args).unwrap_or_else(|err| { + println!("Problem parsing arguments: {}", err); + process::exit(1); + }); + + if let Err(e) = minigrep::run(config) { + println!("Application error: {}", e); + process::exit(1); + } +}