#[macro_use]
extern crate bitflags;

bitflags! {
    struct Flags: u32 {
        const FLAG_A       = 0b00000001;
        const FLAG_B       = 0b00000010;
        const FLAG_C       = 0b00000100;
        const FLAG_ABC     = FLAG_A.bits
                           | FLAG_B.bits
                           | FLAG_C.bits;
    }
}

fn main() {
    let e1 = FLAG_A | FLAG_C;
    let e2 = FLAG_B | FLAG_C;
    assert_eq!((e1 | e2), FLAG_ABC);   // union
    assert_eq!((e1 & e2), FLAG_C);     // intersection
    assert_eq!((e1 - e2), FLAG_A);     // set difference
    assert_eq!(!e2, FLAG_A);           // set complement
}

extern crate byteorder;

use std::io::Cursor;
use byteorder::{BigEndian, ReadBytesExt};
use byteorder::{LittleEndian, WriteBytesExt};

fn main() {
    // Read unsigned 16 bit big-endian integers from a Read type:
    let mut rdr = Cursor::new(vec![2, 5, 3, 0]);
    // Note that we use type parameters to indicate which kind of byte
    // order we want!
    assert_eq!(517, rdr.read_u16::<BigEndian>().unwrap());
    assert_eq!(768, rdr.read_u16::<BigEndian>().unwrap());

    // Write unsigned 16 bit little-endian integers to a Write type:
    let mut wtr = vec![];
    wtr.write_u16::<LittleEndian>(517).unwrap();
    wtr.write_u16::<LittleEndian>(768).unwrap();
    assert_eq!(wtr, vec![5, 2, 0, 3]);
}

extern crate chrono;
use chrono::*;

fn main() {
    let local: DateTime<Local> = Local::now();
    let utc: DateTime<Utc> = Utc::now();

    let dt = Utc.ymd(2014, 11, 28).and_hms(12, 0, 9);

    assert_eq!((dt.year(), dt.month(), dt.day()), (2014, 11, 28));
    assert_eq!((dt.hour(), dt.minute(), dt.second()), (12, 0, 9));

    assert_eq!(dt.format("%Y-%m-%d %H:%M:%S").to_string(), "2014-11-28 12:00:09");
    assert_eq!(dt.format("%a %b %e %T %Y").to_string(), "Fri Nov 28 12:00:09 2014");

    assert_eq!(format!("{}", dt), "2014-11-28 12:00:09 UTC");
}

extern crate clap;
use clap::{Arg, App, SubCommand};

fn main() {
    let app = App::new("My Super Program")
        .version("1.0")
        .author("Kevin K. <kbknapp@gmail.com>")
        .about("Does awesome things")
        .arg(Arg::with_name("config")
             .short("c")
             .long("config")
             .value_name("FILE")
             .help("Sets a custom config file")
             .takes_value(true))
        .arg(Arg::with_name("INPUT")
             .help("Sets the input file to use")
             .required(true)
             .index(1))
        .subcommand(SubCommand::with_name("test")
                    .about("controls testing features")
                    .arg(Arg::with_name("debug")
                         .short("d")
                         .help("print debug information verbosely")));

    // Parse the command line arguments
    let matches = app.get_matches();

    let config = matches.value_of("config").unwrap_or("default.conf");
    let input = matches.value_of("INPUT").unwrap();

    // Handle subcommands
    match matches.subcommand() {
        ("clone",  Some(sub_matches)) => {
            if matches.is_present("d") {
                // ...
            }
        },
        ("push",   Some(sub_matches)) => {},
        ("commit", Some(sub_matches)) => {},
        _ => {},
    }
}

extern crate encoding_rs;
use encoding_rs::*;

fn main() {
    let expected = "\u{30CF}\u{30ED}\u{30FC}\u{30FB}\u{30EF}\u{30FC}\u{30EB}\u{30C9}";
    let encoded = b"\x83n\x83\x8D\x81[\x81E\x83\x8F\x81[\x83\x8B\x83h";

    let (decoded, encoding_used, had_errors) = SHIFT_JIS.decode(encoded);

    assert_eq!(&decoded[..], expected);
    assert_eq!(encoding_used, SHIFT_JIS);
    assert!(!had_errors);

    println!("Decoded result: {}", decoded);
}

// `error_chain!` can recurse deeply
#![recursion_limit = "1024"]

#[macro_use]
extern crate error_chain;

// We'll put our errors in an `errors` module, and other modules in
// this crate will `use errors::*;` to get access to everything
// `error_chain!` creates.
mod errors {
    // Create the Error, ErrorKind, ResultExt, and Result types
    error_chain! { }
}

use errors::*;

fn main() {
    if let Err(ref e) = run() {
        use ::std::io::Write;
        let stderr = &mut ::std::io::stderr();
        let errmsg = "Error writing to stderr";

        writeln!(stderr, "error: {}", e).expect(errmsg);

        for e in e.iter().skip(1) {
            writeln!(stderr, "caused by: {}", e).expect(errmsg);
        }

        // The backtrace is not always generated. Try to run this example
        // with `RUST_BACKTRACE=1`.
        if let Some(backtrace) = e.backtrace() {
            writeln!(stderr, "backtrace: {:?}", backtrace).expect(errmsg);
        }

        ::std::process::exit(1);
    }
}

// Most functions will return the `Result` type, imported from the
// `errors` module. It is a typedef of the standard `Result` type
// for which the error type is always our own `Error`.
fn run() -> Result<()> {
    use std::fs::File;

    // Use chain_err to attach your own context to errors
    File::open("my secret file")
        .chain_err(|| "unable to open my secret file")?;

    // Use the `bail!` macro to return an error Result, ala `println!`
    bail!("giving up");
}

extern crate flate2;
extern crate tar;

use flate2::read::GzDecoder;
use std::env;
use std::fs::File;
use std::io::{self, BufReader};
use tar::Archive;

fn run() -> Result<(), io::Error> {
    let mut args = env::args().skip(1);
    let tarball = args.next().expect("incorrect argument");
    let outdir = args.next().expect("incorrect argument");

    let archive = File::open(tarball)?;
    let archive = BufReader::new(archive);
    let archive = GzDecoder::new(archive)?;
    let mut archive = Archive::new(archive);

    archive.unpack(outdir)?;

    Ok(())
}

fn main() { run().unwrap() }

extern crate fnv;

use fnv::FnvHashMap;

fn main() {
    let mut map = FnvHashMap::default();
    map.insert(1, "one");
    map.insert(2, "two");
    map.insert(3, "three");

    for (number, word) in map.iter() {
        println!("Number {}: {}", number, word);
    }

    map.remove(&(2));
    println!("The length of HashMap is {}.", map.len());
    println!("The first element is {}.", map.get(&(1)).unwrap());
}

extern crate itertools;

use itertools::{join, max, sorted};

fn main(){
    let a = [3, 2, 5, 8, 7];

    // Combine all iterator elements into one String,
    // seperated by *.
    println!("{:?}", join(&a, "*"));
    // Return the maximum value of the iterable.
    println!("{:?}", max(a.iter()).unwrap());
    // Collect all the iterable's elements into a
    // sorted vector in ascending order.
    println!("{:?}", sorted(a.iter()));
}

#[macro_use]
extern crate lazy_static;

use std::collections::HashMap;

lazy_static! {
    static ref HASHMAP: HashMap<u32, &'static str> = {
        let mut m = HashMap::new();
        m.insert(0, "foo");
        m.insert(1, "bar");
        m.insert(2, "baz");
        m
    };
    static ref COUNT: usize = HASHMAP.len();
    static ref NUMBER: u32 = times_two(21);
}

fn times_two(n: u32) -> u32 { n * 2 }

fn main() {
    println!("The map has {} entries.", *COUNT);
    println!("The entry for `0` is \"{}\".", HASHMAP.get(&0).unwrap());
    println!("A expensive calculation on a static results in: {}.", *NUMBER);
}

extern crate libc;

fn main() {
    unsafe {
        libc::exit(0);
    }
}

#[macro_use]
extern crate log;
extern crate env_logger;

use log::LogLevel;

fn main() {
    env_logger::init().unwrap();

    debug!("this is a debug {}", "message");
    error!("this is printed by default");

    if log_enabled!(LogLevel::Info) {
        let x = 3 * 4; // expensive computation
        info!("the answer was: {}", x);
    }
}

extern crate memmap;

use memmap::{Mmap, Protection};
use std::env;
use std::io;
use std::str;

fn run() -> Result<(), io::Error> {
    let mut args = env::args().skip(1);
    let input = args.next().expect("incorrect argument");

    let map = Mmap::open_path(input, Protection::Read)?;
    unsafe {
        let all_bytes = map.as_slice();
        if let Ok(file_str) = str::from_utf8(all_bytes) {
            println!("{}", file_str);
        } else {
            println!("not utf8");
        }
    }
    Ok(())
}

fn main() { run().unwrap() }

#[macro_use(s)]
extern crate ndarray;

use ndarray::{Array3, arr3};

fn main() {
    // Create a three-dimensional f64 array, initialized with zeros
    let mut temperature = Array3::<f64>::zeros((3, 4, 5));

    // Increase the temperature in this location, notice the
    // double-brackets indexing `temperature`
    temperature[[2, 2, 2]] += 0.5;

    // Create a 3-dimensional matrix,
    // 2 submatrices of 2 rows with 3 elements per row, means a shape
    // of `[2, 2, 3]`.
    let a = arr3(&[[[ 1,  2,  3],     // -- 2 rows  \_
                    [ 4,  5,  6]],    // --         /
                   [[ 7,  8,  9],     //            \_ 2 submatrices
                    [10, 11, 12]]]);  //            /
    //  3 columns ..../.../.../

    // This is a 2 x 2 x 3 array
    assert_eq!(a.shape(), &[2, 2, 3]);

    // Let’s create a slice of `a` with
    //
    // - Both of the submatrices of the greatest dimension: `..`
    // - Only the first row in each submatrix: `0..1`
    // - Every element in each row: `..`
    let b = a.slice(s![.., 0..1, ..]);

    // This is the result of the above slice into `a`
    let c = arr3(&[[[ 1,  2,  3]],
                   [[ 7,  8,  9]]]);
    assert_eq!(b, c);
    assert_eq!(b.shape(), &[2, 1, 3]);
}

extern crate num;

use num::FromPrimitive;
use num::bigint::BigInt;
use num::rational::{Ratio, BigRational};

fn approx_sqrt(number: u64, iterations: usize) -> BigRational {
    let start: Ratio<BigInt>
        = Ratio::from_integer(FromPrimitive::from_u64(number).unwrap());

    let mut approx = start.clone();

    for _ in 0..iterations {
        approx = (&approx + (&start / &approx)) /
            Ratio::from_integer(FromPrimitive::from_u64(2).unwrap());
    }

    approx
}

fn main() {
    println!("{}", approx_sqrt(10, 4)); // prints 4057691201/1283082416
}

extern crate threadpool;
extern crate num_cpus;

use threadpool::ThreadPool;
use std::sync::mpsc::channel;

fn main() {
    // Get the number of cpus on current machine
    let n_workers = num_cpus::get();
    let n_jobs = 8;

    // Create the thread pool with amount of workers equal to cores
    let pool = ThreadPool::new(n_workers);

    // Create transmitter and receiver channel
    let (tx, rx) = channel();

    // For each job grab a free worker from the pool and execute
    for _ in 0..n_jobs {
        let tx = tx.clone();
        pool.execute(move || {
            tx.send(1).unwrap();
        });
    }

    assert_eq!(rx.iter().take(n_jobs).fold(0, |a, b| a + b), 8);
}

extern crate rand;

use rand::Rng;

fn main() {
    let mut rng = rand::thread_rng();
    if rng.gen() { // random bool
        println!("i32: {}, u32: {}", rng.gen::<i32>(), rng.gen::<u32>())
    }

    let tuple = rand::random::<(f64, char)>();
    println!("{:?}", tuple)
}

extern crate rayon;

use rayon::prelude::*;

fn main() {
    let mut input = (0..1000).collect::<Vec<_>>();

    // Calculate the sum of squares
    let sq_sum: i32 = input.par_iter()
                      .map(|&i| i * i)
                      .sum();

    // Increment each element in parallel
    input.par_iter_mut()
        .for_each(|p| *p += 1);

    // Parallel quicksort
    let mut input = (0..1000).rev().collect::<Vec<_>>();
    quick_sort(&mut input);
}

fn quick_sort<T: PartialOrd + Send>(v: &mut [T]) {
    if v.len() <= 1 {
        return;
    }

    let mid = partition(v);
    let (lo, hi) = v.split_at_mut(mid);
    rayon::join(|| quick_sort(lo), || quick_sort(hi));
}

fn partition<T: PartialOrd + Send>(v: &mut [T]) -> usize {
    let pivot = v.len() - 1;
    let mut i = 0;
    for j in 0..pivot {
        if v[j] <= v[pivot] {
            v.swap(i, j);
            i += 1;
        }
    }
    v.swap(i, pivot);
    i
}

extern crate regex;

use regex::Regex;

fn main() {
    // Find a date
    let re = Regex::new(r"^\d{4}-\d{2}-\d{2}$").unwrap();
    assert!(re.is_match("2014-01-01"));

    // Iterating over capture groups
    let re = Regex::new(r"(\d{4})-(\d{2})-(\d{2})").unwrap();
    let text = "2012-03-14, 2013-01-01 and 2014-07-05";
    for cap in re.captures_iter(text) {
        println!("Month: {} Day: {} Year: {}", &cap[2], &cap[3], &cap[1]);
    }
}

extern crate reqwest;

use std::collections::HashMap;
use std::io::{BufRead, BufReader};

fn main() {
    // Make a GET request
    let resp = reqwest::get("https://www.rust-lang.org").unwrap();
    assert!(resp.status().is_success());

    let lines = BufReader::new(resp)
                          .lines()
                          .filter_map(|l| l.ok())
                          .take(10);
    for line in lines {
        println!("{}", line);
    }

    // Make a POST request
    let client = reqwest::Client::new().unwrap();
    let res = client.post("http://httpbin.org/post").unwrap()
        .body("the exact body that is sent")
        .send();

    // Convert to/from JSON automatically
    let mut map = HashMap::new();
    map.insert("lang", "rust");
    map.insert("body", "json");

    // This will POST a body of `{"lang":"rust","body":"json"}`
    let client = reqwest::Client::new().unwrap();
    let res = client.post("http://httpbin.org/post").unwrap()
        .json(&map).unwrap()
        .send();
}

extern crate semver;

use semver::Version;

fn main() {
    // Construct Version objects
    assert!(Version::parse("1.2.3") == Ok(Version {
        major: 1,
        minor: 2,
        patch: 3,
        pre: vec!(),
        build: vec!(),
    }));

    // Compare Versions
    assert!(Version::parse("1.2.3-alpha") != Version::parse("1.2.3-beta"));
    assert!(Version::parse("1.2.3-alpha2") >  Version::parse("1.2.0"));

    // Increment patch number of mutable Version
    let mut bugfix_release = Version::parse("1.0.0").unwrap();
    bugfix_release.increment_patch();

    assert_eq!(Ok(bugfix_release), Version::parse("1.0.1"));
}

#[macro_use]
extern crate serde_derive;
extern crate serde_json;

use serde_json::Value;

#[derive(Serialize, Deserialize, Debug)]
struct Contact {
    name: String,
    age: u32,
}

fn main() {
    let contact = Contact {
        name: "Brian".to_string(),
        age: 21,
    };

    // Serialize data structures to strings in JSON format
    let contact: String = serde_json::to_string(&contact).unwrap();
    println!("{}", contact);

    // Deserialize data structures from JSON strings
    let contact: Contact = serde_json::from_str(&contact).unwrap();
    println!("{:?}", contact);

    // Convert to arbitrary JSON `Value` type
    let contact: Value = serde_json::to_value(&contact).unwrap();
    println!("{:?}", contact);
}

extern crate serde_json;

use serde_json::Value;

fn main() {
    // Some JSON input data as a &str. Maybe this comes from the user.
    let data = r#"{
                    "name": "John Doe",
                    "age": 43,
                    "phones": [
                      "+44 1234567",
                      "+44 2345678"
                    ]
                  }"#;

    // Parse the string of data into serde_json::Value.
    let v: Value = serde_json::from_str(data).unwrap();

    // Access parts of the data by indexing with square brackets.
    println!("Please call {} at the number {}", v["name"], v["phones"][0]);
}

extern crate flate2;
extern crate tar;

use flate2::read::GzDecoder;
use std::env;
use std::fs::File;
use std::io::{self, BufReader};
use tar::Archive;

fn run() -> Result<(), io::Error> {
    let mut args = env::args().skip(1);
    let tarball = args.next().expect("incorrect argument");
    let outdir = args.next().expect("incorrect argument");

    let archive = File::open(tarball)?;
    let archive = BufReader::new(archive);
    let archive = GzDecoder::new(archive)?;
    let mut archive = Archive::new(archive);

    archive.unpack(outdir)?;

    Ok(())
}

fn main() { run().unwrap() }

extern crate tempdir;

use std::fs::File;
use std::io::Write;
use tempdir::TempDir;

fn main() {
    // Create a directory inside of `std::env::temp_dir()`, named with
    // the prefix "example".
    let tmp_dir = TempDir::new("example").expect("create temp dir");
    let file_path = tmp_dir.path().join("my-temporary-note.txt");
    let mut tmp_file = File::create(file_path).expect("create temp file");
    writeln!(tmp_file, "Brian was here. Briefly.").expect("write temp file");

    // By closing the `TempDir` explicitly, we can check that it has
    // been deleted successfully. If we don't close it explicitly,
    // the directory will still be deleted when `tmp_dir` goes out
    // of scope, but we won't know whether deleting the directory
    // succeeded.
    drop(tmp_file);
    tmp_dir.close().expect("delete temp dir");
}

extern crate threadpool;
extern crate num_cpus;

use threadpool::ThreadPool;
use std::sync::mpsc::channel;

fn main() {
    // Get the number of cpus on current machine
    let n_workers = num_cpus::get();
    let n_jobs = 8;

    // Create the thread pool with amount of workers equal to cores
    let pool = ThreadPool::new(n_workers);

    // Create transmitter and receiver channel
    let (tx, rx) = channel();

    // For each job grab a free worker from the pool and execute
    for _ in 0..n_jobs {
        let tx = tx.clone();
        pool.execute(move || {
            tx.send(1).unwrap();
        });
    }

    assert_eq!(rx.iter().take(n_jobs).fold(0, |a, b| a + b), 8);
}

extern crate toml;

use toml::Value;

fn main() {
    let toml = r#"
    [test]
    foo = "bar"
"#;

    let value = toml.parse::<Value>().unwrap();
    println!("{:?}", value);
}

extern crate url;

use url::{Url, Host};

fn main() {
    let issue_list_url = Url::parse(
        "https://github.com/rust-lang/rust/issues?labels=E-easy&state=open"
    ).unwrap();

    assert!(issue_list_url.scheme() == "https");
    assert!(issue_list_url.username() == "");
    assert!(issue_list_url.password() == None);
    assert!(issue_list_url.host_str() == Some("github.com"));
    assert!(issue_list_url.host() == Some(Host::Domain("github.com")));
    assert!(issue_list_url.port() == None);
    assert!(issue_list_url.path() == "/rust-lang/rust/issues");
    assert!(issue_list_url.path_segments().map(|c| c.collect::<Vec<_>>()) ==
            Some(vec!["rust-lang", "rust", "issues"]));
    assert!(issue_list_url.query() == Some("labels=E-easy&state=open"));
    assert!(issue_list_url.fragment() == None);
    assert!(!issue_list_url.cannot_be_a_base());
}

extern crate walkdir;

use walkdir::{WalkDir, Error};

fn run() -> Result<(), Error> {
    let wd = WalkDir::new(".");

    for entry in wd {
        let entry = entry?;
        println!("{}", entry.path().display());
    }

    Ok(())
}

fn main() { run().unwrap(); }

#[macro_use]
extern crate bitflags;

bitflags! {
    struct Flags: u32 {
        const FLAG_A       = 0b00000001;
        const FLAG_B       = 0b00000010;
        const FLAG_C       = 0b00000100;
        const FLAG_ABC     = FLAG_A.bits
                           | FLAG_B.bits
                           | FLAG_C.bits;
    }
}

fn main() {
    let e1 = FLAG_A | FLAG_C;
    let e2 = FLAG_B | FLAG_C;
    assert_eq!((e1 | e2), FLAG_ABC);   // union
    assert_eq!((e1 & e2), FLAG_C);     // intersection
    assert_eq!((e1 - e2), FLAG_A);     // set difference
    assert_eq!(!e2, FLAG_A);           // set complement
}