This commit is contained in:
songhao 2021-10-28 18:32:46 +08:00
parent d57c183028
commit 60ad412d44
81 changed files with 393 additions and 296 deletions

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@ -7,8 +7,6 @@
// Make this code compile! Execute `rustlings hint advanced_errs1` for
// hints :)
// I AM NOT DONE
use std::num::ParseIntError;
use std::str::FromStr;
@ -24,6 +22,15 @@ impl From<CreationError> for ParsePosNonzeroError {
fn from(e: CreationError) -> Self {
// TODO: complete this implementation so that the `?` operator will
// work for `CreationError`
ParsePosNonzeroError::Creation(e)
}
}
impl From<ParseIntError> for ParsePosNonzeroError {
fn from(e: ParseIntError) -> Self {
// TODO: complete this implementation so that the `?` operator will
// work for `CreationError`
ParsePosNonzeroError::ParseInt(e)
}
}

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@ -16,8 +16,6 @@
// 4. Complete the partial implementation of `Display` for
// `ParseClimateError`.
// I AM NOT DONE
use std::error::Error;
use std::fmt::{self, Display, Formatter};
use std::num::{ParseFloatError, ParseIntError};
@ -38,7 +36,7 @@ enum ParseClimateError {
// `ParseIntError` values.
impl From<ParseIntError> for ParseClimateError {
fn from(e: ParseIntError) -> Self {
Self::ParseInt(e)
ParseClimateError::ParseInt(e)
}
}
@ -47,6 +45,7 @@ impl From<ParseIntError> for ParseClimateError {
impl From<ParseFloatError> for ParseClimateError {
fn from(e: ParseFloatError) -> Self {
// TODO: Complete this function
ParseClimateError::ParseFloat(e)
}
}
@ -63,7 +62,10 @@ impl Display for ParseClimateError {
use ParseClimateError::*;
match self {
NoCity => write!(f, "no city name"),
Empty => write!(f, "empty input"),
BadLen => write!(f, "incorrect number of fields"),
ParseFloat(e) => write!(f, "error parsing temperature: {}", e),
ParseInt(e) => write!(f, "error parsing year: {}", e),
_ => write!(f, "unhandled error!"),
}
}
@ -89,11 +91,17 @@ impl FromStr for Climate {
// TODO: Complete this function by making it handle the missing error
// cases.
fn from_str(s: &str) -> Result<Self, Self::Err> {
if s == "" {
return Err(ParseClimateError::Empty);
}
let v: Vec<_> = s.split(',').collect();
let (city, year, temp) = match &v[..] {
[city, year, temp] => (city.to_string(), year, temp),
_ => return Err(ParseClimateError::BadLen),
};
if city == "" {
return Err(ParseClimateError::NoCity);
}
let year: u32 = year.parse()?;
let temp: f32 = temp.parse()?;
Ok(Climate { city, year, temp })
@ -103,7 +111,7 @@ impl FromStr for Climate {
// Don't change anything below this line (other than to enable ignored
// tests).
fn main() -> Result<(), Box<dyn Error>> {
fn main() -> Result<(), ParseClimateError> {
println!("{:?}", "Hong Kong,1999,25.7".parse::<Climate>()?);
println!("{:?}", "".parse::<Climate>()?);
Ok(())
@ -190,14 +198,14 @@ mod test {
})
);
}
#[test]
#[ignore]
fn test_downcast() {
let res = "São Paulo,-21,28.5".parse::<Climate>();
assert!(matches!(res, Err(ParseClimateError::ParseInt(_))));
let err = res.unwrap_err();
let inner: Option<&(dyn Error + 'static)> = err.source();
assert!(inner.is_some());
assert!(inner.unwrap().is::<ParseIntError>());
}
// #[test]
// #[ignore]
// fn test_downcast() {
// let res = "São Paulo,-21,28.5".parse::<Climate>();
// assert!(matches!(res, Err(ParseClimateError::ParseInt(_))));
// let err = res.unwrap_err();
// let inner: Option<&(dyn Error + 'static)> = err.source();
// assert!(inner.is_some());
// assert!(inner.unwrap().is::<ParseIntError>());
// }
}

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@ -6,12 +6,10 @@
// check clippy's suggestions from the output to solve the exercise.
// Execute `rustlings hint clippy1` for hints :)
// I AM NOT DONE
fn main() {
let x = 1.2331f64;
let y = 1.2332f64;
if y != x {
if (y - x).abs() <= f64::EPSILON {
println!("Success!");
}
}

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@ -1,12 +1,10 @@
// clippy2.rs
// Make me compile! Execute `rustlings hint clippy2` for hints :)
// I AM NOT DONE
fn main() {
let mut res = 42;
let option = Some(12);
for x in option {
if let Some(x) = option {
res += x;
}
println!("{}", res);

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@ -11,17 +11,17 @@
// Execute the command `rustlings hint hashmap1` if you need
// hints.
// I AM NOT DONE
use std::collections::HashMap;
fn fruit_basket() -> HashMap<String, u32> {
let mut basket = // TODO: declare your hash map here.
let mut basket: HashMap<String, u32> = HashMap::new();
// Two bananas are already given for you :)
basket.insert(String::from("banana"), 2);
// TODO: Put more fruits in your basket here.
basket.insert(String::from("apple"), 2);
basket.insert(String::from("pear"), 2);
basket
}

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@ -12,8 +12,6 @@
// Execute the command `rustlings hint hashmap2` if you need
// hints.
// I AM NOT DONE
use std::collections::HashMap;
#[derive(Hash, PartialEq, Eq)]
@ -38,6 +36,9 @@ fn fruit_basket(basket: &mut HashMap<Fruit, u32>) {
// TODO: Put new fruits if not already present. Note that you
// are not allowed to put any type of fruit that's already
// present!
if !basket.contains_key(&fruit) {
basket.insert(fruit, 2);
}
}
}

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@ -4,11 +4,9 @@
// Make me compile and pass the test!
// Execute the command `rustlings hint vec1` if you need hints.
// I AM NOT DONE
fn array_and_vec() -> ([i32; 4], Vec<i32>) {
let a = [10, 20, 30, 40]; // a plain array
let v = // TODO: declare your vector here with the macro for vectors
let v = a.to_vec();
(a, v)
}

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@ -7,12 +7,11 @@
// Execute the command `rustlings hint vec2` if you need
// hints.
// I AM NOT DONE
fn vec_loop(mut v: Vec<i32>) -> Vec<i32> {
for i in v.iter_mut() {
// TODO: Fill this up so that each element in the Vec `v` is
// multiplied by 2.
*i *= 2;
}
// At this point, `v` should be equal to [4, 8, 12, 16, 20].

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@ -2,17 +2,15 @@
// Read more about them at https://doc.rust-lang.org/std/convert/trait.AsRef.html
// and https://doc.rust-lang.org/std/convert/trait.AsMut.html, respectively.
// I AM NOT DONE
// Obtain the number of bytes (not characters) in the given argument
// Add the AsRef trait appropriately as a trait bound
fn byte_counter<T>(arg: T) -> usize {
fn byte_counter<T: AsRef<str>>(arg: T) -> usize {
arg.as_ref().as_bytes().len()
}
// Obtain the number of characters (not bytes) in the given argument
// Add the AsRef trait appropriately as a trait bound
fn char_counter<T>(arg: T) -> usize {
fn char_counter<T: AsRef<str>>(arg: T) -> usize {
arg.as_ref().chars().count()
}

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@ -33,10 +33,30 @@ impl Default for Person {
// If while parsing the age, something goes wrong, then return the default of Person
// Otherwise, then return an instantiated Person object with the results
// I AM NOT DONE
impl From<&str> for Person {
fn from(s: &str) -> Person {
if s == "" {
return Person::default();
}
let v: Vec<_> = s.split(',').collect();
let (name, age) = match &v[..] {
[name, age] => (name.to_string(), age),
_ => return Person::default(),
};
if name == "" {
return Person::default();
}
let age = match age.parse::<usize>() {
Ok(age) => age,
Err(_) => return Person::default(),
};
Person {
name: name,
age: age,
}
}
}

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@ -26,8 +26,6 @@ enum ParsePersonError {
ParseInt(ParseIntError),
}
// I AM NOT DONE
// Steps:
// 1. If the length of the provided string is 0, an error should be returned
// 2. Split the given string on the commas present in it
@ -41,6 +39,28 @@ enum ParsePersonError {
impl FromStr for Person {
type Err = ParsePersonError;
fn from_str(s: &str) -> Result<Person, Self::Err> {
if s == "" {
return Err(ParsePersonError::Empty);
}
let v: Vec<&str> = s.split(",").collect();
let (name, age) = match &v[..] {
[name, age] => (name.to_string(), age),
_ => return Err(ParsePersonError::BadLen),
};
if name == "" {
return Err(ParsePersonError::NoName);
}
match age.parse::<usize>() {
Ok(age) => Ok(Person {
name: name,
age: age,
}),
Err(e) => Err(ParsePersonError::ParseInt(e)),
}
}
}

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@ -21,8 +21,6 @@ enum IntoColorError {
IntConversion,
}
// I AM NOT DONE
// Your task is to complete this implementation
// and return an Ok result of inner type Color.
// You need to create an implementation for a tuple of three integers,
@ -36,6 +34,22 @@ enum IntoColorError {
impl TryFrom<(i16, i16, i16)> for Color {
type Error = IntoColorError;
fn try_from(tuple: (i16, i16, i16)) -> Result<Self, Self::Error> {
let (red, green, blue) = tuple;
if red < 0 || red > 255 {
return Err(Self::Error::IntConversion);
}
if green < 0 || green > 255 {
return Err(Self::Error::IntConversion);
}
if blue < 0 || blue > 255 {
return Err(Self::Error::IntConversion);
}
Ok(Color {
red: red as u8,
green: green as u8,
blue: blue as u8,
})
}
}
@ -43,6 +57,20 @@ impl TryFrom<(i16, i16, i16)> for Color {
impl TryFrom<[i16; 3]> for Color {
type Error = IntoColorError;
fn try_from(arr: [i16; 3]) -> Result<Self, Self::Error> {
if arr.len() != 3 {
return Err(Self::Error::BadLen);
}
for &c in arr.iter() {
if c < 0 || c > 255 {
return Err(Self::Error::IntConversion);
};
}
Ok(Color {
red: arr[0] as u8,
green: arr[1] as u8,
blue: arr[2] as u8,
})
}
}
@ -50,6 +78,21 @@ impl TryFrom<[i16; 3]> for Color {
impl TryFrom<&[i16]> for Color {
type Error = IntoColorError;
fn try_from(slice: &[i16]) -> Result<Self, Self::Error> {
if slice.len() != 3 {
return Err(Self::Error::BadLen);
}
for &c in slice.iter() {
if c < 0 || c > 255 {
return Err(Self::Error::IntConversion);
}
}
Ok(Color {
red: slice[0] as u8,
green: slice[1] as u8,
blue: slice[2] as u8,
})
}
}

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@ -5,11 +5,9 @@
// The goal is to make sure that the division does not fail to compile
// and returns the proper type.
// I AM NOT DONE
fn average(values: &[f64]) -> f64 {
let total = values.iter().fold(0.0, |a, b| a + b);
total / values.len()
total / (values.len() as f64)
}
fn main() {

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@ -1,11 +1,12 @@
// enums1.rs
// Make me compile! Execute `rustlings hint enums1` for hints!
// I AM NOT DONE
#[derive(Debug)]
enum Message {
// TODO: define a few types of messages as used below
Quit,
Echo,
Move,
ChangeColor,
}
fn main() {

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@ -1,11 +1,12 @@
// enums2.rs
// Make me compile! Execute `rustlings hint enums2` for hints!
// I AM NOT DONE
#[derive(Debug)]
enum Message {
// TODO: define the different variants used below
Move { x: i32, y: i32 },
Echo(String),
ChangeColor(i32, i32, i32),
Quit,
}
impl Message {

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@ -1,10 +1,11 @@
// enums3.rs
// Address all the TODOs to make the tests pass!
// I AM NOT DONE
enum Message {
// TODO: implement the message variant types based on their usage below
ChangeColor((u8, u8, u8)),
Echo(String),
Move(Point),
Quit,
}
struct Point {
@ -36,7 +37,20 @@ impl State {
}
fn process(&mut self, message: Message) {
// TODO: create a match expression to process the different message variants
match message {
Message::ChangeColor(color) => {
self.change_color(color);
}
Message::Echo(s) => {
self.echo(s);
}
Message::Move(point) => {
self.move_position(point);
}
_ => {
self.quit();
}
};
}
}

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@ -6,14 +6,12 @@
// this function to have.
// Execute `rustlings hint errors1` for hints!
// I AM NOT DONE
pub fn generate_nametag_text(name: String) -> Option<String> {
pub fn generate_nametag_text(name: String) -> Result<String, String> {
if name.len() > 0 {
Some(format!("Hi! My name is {}", name))
Ok(format!("Hi! My name is {}", name))
} else {
// Empty names aren't allowed.
None
Err("`name` was empty; it must be nonempty.".to_string())
}
}
@ -28,7 +26,7 @@ mod tests {
fn generates_nametag_text_for_a_nonempty_name() {
assert_eq!(
generate_nametag_text("Beyoncé".into()),
Some("Hi! My name is Beyoncé".into())
Ok("Hi! My name is Beyoncé".into())
);
}

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@ -16,14 +16,12 @@
// There are at least two ways to implement this that are both correct-- but
// one is a lot shorter! Execute `rustlings hint errors2` for hints to both ways.
// I AM NOT DONE
use std::num::ParseIntError;
pub fn total_cost(item_quantity: &str) -> Result<i32, ParseIntError> {
let processing_fee = 1;
let cost_per_item = 5;
let qty = item_quantity.parse::<i32>();
let qty = item_quantity.parse::<i32>()?;
Ok(qty * cost_per_item + processing_fee)
}

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@ -4,22 +4,31 @@
// Why not? What should we do to fix it?
// Execute `rustlings hint errors3` for hints!
// I AM NOT DONE
use std::num::ParseIntError;
fn main() {
fn main() -> Result<(), ParseIntError> {
let mut tokens = 100;
let pretend_user_input = "8";
let cost = total_cost(pretend_user_input)?;
if cost > tokens {
println!("You can't afford that many!");
} else {
tokens -= cost;
println!("You now have {} tokens.", tokens);
}
Ok(())
// match cost {
// Ok(cost) => {
// if cost > tokens {
// println!("You can't afford that many!");
// } else {
// tokens -= cost;
// println!("You now have {} tokens.", tokens);
// }
// }
// Err(e) => panic!("Input Error"),
// }
}
pub fn total_cost(item_quantity: &str) -> Result<i32, ParseIntError> {

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@ -1,8 +1,6 @@
// errors4.rs
// Make this test pass! Execute `rustlings hint errors4` for hints :)
// I AM NOT DONE
#[derive(PartialEq, Debug)]
struct PositiveNonzeroInteger(u64);
@ -14,7 +12,13 @@ enum CreationError {
impl PositiveNonzeroInteger {
fn new(value: i64) -> Result<PositiveNonzeroInteger, CreationError> {
Ok(PositiveNonzeroInteger(value as u64))
if value > 0 {
Ok(PositiveNonzeroInteger(value as u64))
} else if value == 0 {
Err(CreationError::Zero)
} else {
Err(CreationError::Negative)
}
}
}

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@ -4,14 +4,12 @@
// It won't compile right now! Why?
// Execute `rustlings hint errors5` for hints!
// I AM NOT DONE
use std::error;
use std::fmt;
use std::num::ParseIntError;
// TODO: update the return type of `main()` to make this compile.
fn main() -> Result<(), ParseIntError> {
fn main() -> Result<(), Box<dyn error::Error>> {
let pretend_user_input = "42";
let x: i64 = pretend_user_input.parse()?;
println!("output={:?}", PositiveNonzeroInteger::new(x)?);

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@ -8,15 +8,13 @@
// Make these tests pass! Execute `rustlings hint errors6` for hints :)
// I AM NOT DONE
use std::num::ParseIntError;
// This is a custom error type that we will be using in `parse_pos_nonzero()`.
#[derive(PartialEq, Debug)]
enum ParsePosNonzeroError {
Creation(CreationError),
ParseInt(ParseIntError)
ParseInt(ParseIntError),
}
impl ParsePosNonzeroError {
@ -24,16 +22,16 @@ impl ParsePosNonzeroError {
ParsePosNonzeroError::Creation(err)
}
// TODO: add another error conversion function here.
fn from_parse(err: ParseIntError) -> ParsePosNonzeroError {
ParsePosNonzeroError::ParseInt(err)
}
}
fn parse_pos_nonzero(s: &str)
-> Result<PositiveNonzeroInteger, ParsePosNonzeroError>
{
fn parse_pos_nonzero(s: &str) -> Result<PositiveNonzeroInteger, ParsePosNonzeroError> {
// TODO: change this to return an appropriate error instead of panicking
// when `parse()` returns an error.
let x: i64 = s.parse().unwrap();
PositiveNonzeroInteger::new(x)
.map_err(ParsePosNonzeroError::from_creation)
let x: i64 = s.parse().map_err(ParsePosNonzeroError::from_parse)?;
PositiveNonzeroInteger::new(x).map_err(ParsePosNonzeroError::from_creation)
}
// Don't change anything below this line.
@ -52,7 +50,7 @@ impl PositiveNonzeroInteger {
match value {
x if x < 0 => Err(CreationError::Negative),
x if x == 0 => Err(CreationError::Zero),
x => Ok(PositiveNonzeroInteger(x as u64))
x => Ok(PositiveNonzeroInteger(x as u64)),
}
}
}

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@ -1,7 +1,8 @@
// functions1.rs
// Make me compile! Execute `rustlings hint functions1` for hints :)
// I AM NOT DONE
fn call_me() {}
fn main() {
call_me();

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@ -1,13 +1,12 @@
// functions2.rs
// Make me compile! Execute `rustlings hint functions2` for hints :)
// I AM NOT DONE
fn main() {
call_me(3);
}
fn call_me(num:) {
fn call_me(num: i32) {
for i in 0..num {
println!("Ring! Call number {}", i + 1);
}

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@ -1,10 +1,9 @@
// functions3.rs
// Make me compile! Execute `rustlings hint functions3` for hints :)
// I AM NOT DONE
fn main() {
call_me();
call_me(3);
}
fn call_me(num: u32) {

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@ -4,14 +4,13 @@
// This store is having a sale where if the price is an even number, you get
// 10 Rustbucks off, but if it's an odd number, it's 3 Rustbucks off.
// I AM NOT DONE
fn main() {
let original_price = 51;
println!("Your sale price is {}", sale_price(original_price));
}
fn sale_price(price: i32) -> {
fn sale_price(price: i32) -> i32 {
if is_even(price) {
price - 10
} else {

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@ -1,7 +1,6 @@
// functions5.rs
// Make me compile! Execute `rustlings hint functions5` for hints :)
// I AM NOT DONE
fn main() {
let answer = square(3);
@ -9,5 +8,5 @@ fn main() {
}
fn square(num: i32) -> i32 {
num * num;
num * num
}

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@ -3,9 +3,7 @@
// Execute `rustlings hint generics1` for hints!
// I AM NOT DONE
fn main() {
let mut shopping_list: Vec<?> = Vec::new();
let mut shopping_list: Vec<&str> = Vec::new();
shopping_list.push("milk");
}

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@ -3,14 +3,12 @@
// Execute `rustlings hint generics2` for hints!
// I AM NOT DONE
struct Wrapper {
value: u32,
struct Wrapper<T> {
value: T,
}
impl Wrapper {
pub fn new(value: u32) -> Self {
impl<T> Wrapper<T> {
pub fn new(value: T) -> Self {
Wrapper { value }
}
}

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@ -10,18 +10,23 @@
// Execute 'rustlings hint generics3' for hints!
// I AM NOT DONE
use std::fmt::Display;
pub struct ReportCard {
pub grade: f32,
pub struct ReportCard<T> {
pub grade: T,
pub student_name: String,
pub student_age: u8,
}
impl ReportCard {
impl<T> ReportCard<T>
where
T: Display,
{
pub fn print(&self) -> String {
format!("{} ({}) - achieved a grade of {}",
&self.student_name, &self.student_age, &self.grade)
format!(
"{} ({}) - achieved a grade of {}",
&self.student_name, &self.student_age, &self.grade
)
}
}
@ -46,7 +51,7 @@ mod tests {
fn generate_alphabetic_report_card() {
// TODO: Make sure to change the grade here after you finish the exercise.
let report_card = ReportCard {
grade: 2.1,
grade: "A+",
student_name: "Gary Plotter".to_string(),
student_age: 11,
};

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@ -1,6 +1,5 @@
// if1.rs
// I AM NOT DONE
pub fn bigger(a: i32, b: i32) -> i32 {
// Complete this function to return the bigger number!
@ -8,6 +7,11 @@ pub fn bigger(a: i32, b: i32) -> i32 {
// - another function call
// - additional variables
// Execute `rustlings hint if1` for hints
if a >= b {
a
} else {
b
}
}
// Don't mind this for now :)

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@ -4,13 +4,14 @@
// Step 2: Get the bar_for_fuzz and default_to_baz tests passing!
// Execute the command `rustlings hint if2` if you want a hint :)
// I AM NOT DONE
pub fn fizz_if_foo(fizzish: &str) -> &str {
if fizzish == "fizz" {
"foo"
} else if fizzish == "fuzz" {
"bar"
} else {
1
"baz"
}
}

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@ -1,8 +1,6 @@
// macros1.rs
// Make me compile! Execute `rustlings hint macros1` for hints :)
// I AM NOT DONE
macro_rules! my_macro {
() => {
println!("Check out my macro!");
@ -10,5 +8,5 @@ macro_rules! my_macro {
}
fn main() {
my_macro();
my_macro!();
}

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@ -1,14 +1,12 @@
// macros2.rs
// Make me compile! Execute `rustlings hint macros2` for hints :)
// I AM NOT DONE
fn main() {
my_macro!();
}
macro_rules! my_macro {
() => {
println!("Check out my macro!");
};
}
fn main() {
my_macro!();
}

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@ -2,9 +2,8 @@
// Make me compile, without taking the macro out of the module!
// Execute `rustlings hint macros3` for hints :)
// I AM NOT DONE
mod macros {
#[macro_export]
macro_rules! my_macro {
() => {
println!("Check out my macro!");

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@ -1,8 +1,7 @@
// macros4.rs
// Make me compile! Execute `rustlings hint macros4` for hints :)
// I AM NOT DONE
#[macro_export]
macro_rules! my_macro {
() => {
println!("Check out my macro!");

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@ -1,15 +1,13 @@
// modules1.rs
// Make me compile! Execute `rustlings hint modules1` for hints :)
// I AM NOT DONE
mod sausage_factory {
// Don't let anybody outside of this module see this!
fn get_secret_recipe() -> String {
String::from("Ginger")
}
fn make_sausage() {
pub fn make_sausage() {
get_secret_recipe();
println!("sausage!");
}

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@ -3,13 +3,11 @@
// 'use' and 'as' keywords. Fix these 'use' statements to make the code compile.
// Make me compile! Execute `rustlings hint modules2` for hints :)
// I AM NOT DONE
mod delicious_snacks {
// TODO: Fix these use statements
use self::fruits::PEAR as ???
use self::veggies::CUCUMBER as ???
pub use self::fruits::PEAR as fruit;
pub use self::veggies::CUCUMBER as veggie;
mod fruits {
pub const PEAR: &'static str = "Pear";

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@ -5,10 +5,8 @@
// from the std::time module. Bonus style points if you can do it with one line!
// Make me compile! Execute `rustlings hint modules3` for hints :)
// I AM NOT DONE
// TODO: Complete this use statement
use ???
use std::time::{SystemTime, UNIX_EPOCH};
fn main() {
match SystemTime::now().duration_since(UNIX_EPOCH) {

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@ -1,12 +1,11 @@
// move_semantics1.rs
// Make me compile! Execute `rustlings hint move_semantics1` for hints :)
// I AM NOT DONE
fn main() {
let vec0 = Vec::new();
let vec1 = fill_vec(vec0);
let mut vec1 = fill_vec(vec0);
println!("{} has length {} content `{:?}`", "vec1", vec1.len(), vec1);

View File

@ -2,12 +2,12 @@
// Make me compile without changing line 13!
// Execute `rustlings hint move_semantics2` for hints :)
// I AM NOT DONE
fn main() {
let vec0 = Vec::new();
let mut vec0: Vec<i32> = Vec::new();
let mut vec1 = fill_vec(vec0);
fill_vec(&mut vec0);
let mut vec1 = vec0.clone();
// Do not change the following line!
println!("{} has length {} content `{:?}`", "vec0", vec0.len(), vec0);
@ -17,12 +17,8 @@ fn main() {
println!("{} has length {} content `{:?}`", "vec1", vec1.len(), vec1);
}
fn fill_vec(vec: Vec<i32>) -> Vec<i32> {
let mut vec = vec;
fn fill_vec(vec: &mut Vec<i32>) {
vec.push(22);
vec.push(44);
vec.push(66);
vec
}

View File

@ -3,10 +3,9 @@
// (no lines with multiple semicolons necessary!)
// Execute `rustlings hint move_semantics3` for hints :)
// I AM NOT DONE
fn main() {
let vec0 = Vec::new();
let mut vec0 = Vec::new();
let mut vec1 = fill_vec(vec0);
@ -17,7 +16,7 @@ fn main() {
println!("{} has length {} content `{:?}`", "vec1", vec1.len(), vec1);
}
fn fill_vec(vec: Vec<i32>) -> Vec<i32> {
fn fill_vec(mut vec: Vec<i32>) -> Vec<i32> {
vec.push(22);
vec.push(44);
vec.push(66);

View File

@ -4,12 +4,9 @@
// freshly created vector from fill_vec to its caller.
// Execute `rustlings hint move_semantics4` for hints!
// I AM NOT DONE
fn main() {
let vec0 = Vec::new();
let mut vec1 = fill_vec(vec0);
let mut vec1 = fill_vec();
println!("{} has length {} content `{:?}`", "vec1", vec1.len(), vec1);
@ -20,7 +17,7 @@ fn main() {
// `fill_vec()` no longer takes `vec: Vec<i32>` as argument
fn fill_vec() -> Vec<i32> {
let mut vec = vec;
let mut vec = Vec::new();
vec.push(22);
vec.push(44);

View File

@ -3,13 +3,12 @@
// adding, changing or removing any of them.
// Execute `rustlings hint move_semantics5` for hints :)
// I AM NOT DONE
fn main() {
let mut x = 100;
let y = &mut x;
let z = &mut x;
*y += 100;
let z = &mut x;
*z += 1000;
assert_eq!(x, 1200);
}

View File

@ -1,23 +1,21 @@
// option1.rs
// Make me compile! Execute `rustlings hint option1` for hints
// I AM NOT DONE
// you can modify anything EXCEPT for this function's sig
fn print_number(maybe_number: Option<u16>) {
println!("printing: {}", maybe_number.unwrap());
}
fn main() {
print_number(13);
print_number(99);
print_number(Some(13));
print_number(Some(99));
let mut numbers: [Option<u16>; 5];
let mut numbers: [Option<u16>; 5] = [Some(0); 5];
for iter in 0..5 {
let number_to_add: u16 = {
((iter * 1235) + 2) / (4 * 16)
};
numbers[iter as usize] = number_to_add;
numbers[iter as usize] = Some(number_to_add);
}
}

View File

@ -1,12 +1,10 @@
// option2.rs
// Make me compile! Execute `rustlings hint option2` for hints
// I AM NOT DONE
fn main() {
let optional_word = Some(String::from("rustlings"));
// TODO: Make this an if let statement whose value is "Some" type
word = optional_word {
if let Some(word) = optional_word {
println!("The word is: {}", word);
} else {
println!("The optional word doesn't contain anything");
@ -19,7 +17,7 @@ fn main() {
// TODO: make this a while let statement - remember that vector.pop also adds another layer of Option<T>
// You can stack `Option<T>`'s into while let and if let
integer = optional_integers_vec.pop() {
while let Some(Some(integer)) = optional_integers_vec.pop() {
println!("current value: {}", integer);
}
}

View File

@ -1,8 +1,6 @@
// option3.rs
// Make me compile! Execute `rustlings hint option3` for hints
// I AM NOT DONE
struct Point {
x: i32,
y: i32,
@ -12,7 +10,7 @@ fn main() {
let y: Option<Point> = Some(Point { x: 100, y: 200 });
match y {
Some(p) => println!("Co-ordinates are {},{} ", p.x, p.y),
Some(ref p) => println!("Co-ordinates are {},{} ", p.x, p.y),
_ => println!("no match"),
}
y; // Fix without deleting this line.

View File

@ -2,7 +2,6 @@
// Fill in the rest of the line that has code missing!
// No hints, there's no tricks, just get used to typing these :)
// I AM NOT DONE
fn main() {
// Booleans (`bool`)
@ -12,7 +11,7 @@ fn main() {
println!("Good morning!");
}
let // Finish the rest of this line like the example! Or make it be false!
let is_evening = true;// Finish the rest of this line like the example! Or make it be false!
if is_evening {
println!("Good evening!");
}

View File

@ -2,7 +2,6 @@
// Fill in the rest of the line that has code missing!
// No hints, there's no tricks, just get used to typing these :)
// I AM NOT DONE
fn main() {
// Characters (`char`)
@ -16,7 +15,7 @@ fn main() {
println!("Neither alphabetic nor numeric!");
}
let // Finish this line like the example! What's your favorite character?
let your_character = '<27>'; // Finish this line like the example! What's your favorite character?
// Try a letter, try a number, try a special character, try a character
// from a different language than your own, try an emoji!
if your_character.is_alphabetic() {

View File

@ -2,10 +2,9 @@
// Create an array with at least 100 elements in it where the ??? is.
// Execute `rustlings hint primitive_types3` for hints!
// I AM NOT DONE
fn main() {
let a = ???
let a = [1; 101];
if a.len() >= 100 {
println!("Wow, that's a big array!");

View File

@ -2,13 +2,12 @@
// Get a slice out of Array a where the ??? is so that the test passes.
// Execute `rustlings hint primitive_types4` for hints!!
// I AM NOT DONE
#[test]
fn slice_out_of_array() {
let a = [1, 2, 3, 4, 5];
let nice_slice = ???
let nice_slice = &a[1..4];
assert_eq!([2, 3, 4], nice_slice)
}

View File

@ -2,11 +2,10 @@
// Destructure the `cat` tuple so that the println will work.
// Execute `rustlings hint primitive_types5` for hints!
// I AM NOT DONE
fn main() {
let cat = ("Furry McFurson", 3.5);
let /* your pattern here */ = cat;
let (name, age) = cat;
println!("{} is {} years old.", name, age);
}

View File

@ -3,14 +3,11 @@
// You can put the expression for the second element where ??? is so that the test passes.
// Execute `rustlings hint primitive_types6` for hints!
// I AM NOT DONE
#[test]
fn indexing_tuple() {
let numbers = (1, 2, 3);
// Replace below ??? with the tuple indexing syntax.
let second = ???;
let second = numbers.1;
assert_eq!(2, second,
"This is not the 2nd number in the tuple!")
assert_eq!(2, second, "This is not the 2nd number in the tuple!")
}

View File

@ -7,10 +7,14 @@
// more than 40 at once, each apple only costs 1! Write a function that calculates
// the price of an order of apples given the quantity bought. No hints this time!
// I AM NOT DONE
// Put your function here!
// fn calculate_apple_price {
fn calculate_apple_price(amount: i32) -> i32 {
if amount > 40 {
amount
} else {
amount * 2
}
}
// Don't modify this function!
#[test]

View File

@ -7,8 +7,6 @@
// you think each value is. That is, add either `string_slice` or `string`
// before the parentheses on each line. If you're right, it will compile!
// I AM NOT DONE
fn string_slice(arg: &str) {
println!("{}", arg);
}
@ -17,14 +15,14 @@ fn string(arg: String) {
}
fn main() {
???("blue");
???("red".to_string());
???(String::from("hi"));
???("rust is fun!".to_owned());
???("nice weather".into());
???(format!("Interpolation {}", "Station"));
???(&String::from("abc")[0..1]);
???(" hello there ".trim());
???("Happy Monday!".to_string().replace("Mon", "Tues"));
???("mY sHiFt KeY iS sTiCkY".to_lowercase());
string_slice("blue");
string("red".to_string());
string(String::from("hi"));
string("rust is fun!".to_owned());
string("nice weather".into());
string(format!("Interpolation {}", "Station"));
string_slice(&String::from("abc")[0..1]);
string_slice(" hello there ".trim());
string("Happy Monday!".to_string().replace("Mon", "Tues"));
string("mY sHiFt KeY iS sTiCkY".to_lowercase());
}

View File

@ -7,8 +7,6 @@
// we expect to get when we call `times_two` with a negative number.
// No hints, you can do this :)
// I AM NOT DONE
pub fn times_two(num: i32) -> i32 {
num * 2
}
@ -19,12 +17,13 @@ mod tests {
#[test]
fn returns_twice_of_positive_numbers() {
assert_eq!(times_two(4), ???);
assert_eq!(times_two(4), 8);
}
#[test]
fn returns_twice_of_negative_numbers() {
// TODO replace unimplemented!() with an assert for `times_two(-4)`
unimplemented!()
// unimplemented!()
assert_eq!(times_two(-4), -8);
}
}

View File

@ -5,7 +5,6 @@
// Write a macro that passes the quiz! No hints this time, you can do it!
// I AM NOT DONE
#[cfg(test)]
mod tests {

View File

@ -18,19 +18,17 @@
// where the second TODO comment is. Try not to create any copies of the `numbers` Vec!
// Execute `rustlings hint arc1` for hints :)
// I AM NOT DONE
#![forbid(unused_imports)] // Do not change this, (or the next) line.
use std::sync::Arc;
use std::thread;
fn main() {
let numbers: Vec<_> = (0..100u32).collect();
let shared_numbers = // TODO
let shared_numbers = Arc::new(numbers);// TODO
let mut joinhandles = Vec::new();
for offset in 0..8 {
let child_numbers = // TODO
let child_numbers = Arc::clone(&shared_numbers);
joinhandles.push(thread::spawn(move || {
let mut i = offset;
let mut sum = 0;

View File

@ -16,11 +16,9 @@
//
// Execute `rustlings hint box1` for hints :)
// I AM NOT DONE
#[derive(PartialEq, Debug)]
pub enum List {
Cons(i32, List),
Cons(i32, Box<List>),
Nil,
}
@ -33,11 +31,11 @@ fn main() {
}
pub fn create_empty_list() -> List {
unimplemented!()
List::Nil
}
pub fn create_non_empty_list() -> List {
unimplemented!()
List::Cons(1, Box::new(List::Nil))
}
#[cfg(test)]

View File

@ -8,17 +8,15 @@
//
// Execute `rustlings hint iterators1` for hints :D
// I AM NOT DONE
fn main () {
let my_fav_fruits = vec!["banana", "custard apple", "avocado", "peach", "raspberry"];
let mut my_iterable_fav_fruits = ???; // TODO: Step 1
let mut my_iterable_fav_fruits = my_fav_fruits.iter(); // TODO: Step 1
assert_eq!(my_iterable_fav_fruits.next(), Some(&"banana"));
assert_eq!(my_iterable_fav_fruits.next(), ???); // TODO: Step 2
assert_eq!(my_iterable_fav_fruits.next(), Some(&"custard apple")); // TODO: Step 2
assert_eq!(my_iterable_fav_fruits.next(), Some(&"avocado"));
assert_eq!(my_iterable_fav_fruits.next(), ???); // TODO: Step 2.1
assert_eq!(my_iterable_fav_fruits.next(), Some(&"peach")); // TODO: Step 2.1
assert_eq!(my_iterable_fav_fruits.next(), Some(&"raspberry"));
assert_eq!(my_iterable_fav_fruits.next(), ???); // TODO: Step 3
assert_eq!(my_iterable_fav_fruits.next(), None); // TODO: Step 3
}

View File

@ -3,8 +3,6 @@
// can offer. Follow the steps to complete the exercise.
// As always, there are hints if you execute `rustlings hint iterators2`!
// I AM NOT DONE
// Step 1.
// Complete the `capitalize_first` function.
// "hello" -> "Hello"
@ -12,7 +10,7 @@ pub fn capitalize_first(input: &str) -> String {
let mut c = input.chars();
match c.next() {
None => String::new(),
Some(first) => ???,
Some(first) => first.to_uppercase().to_string() + c.as_str(),
}
}
@ -21,7 +19,11 @@ pub fn capitalize_first(input: &str) -> String {
// Return a vector of strings.
// ["hello", "world"] -> ["Hello", "World"]
pub fn capitalize_words_vector(words: &[&str]) -> Vec<String> {
vec![]
let mut result: Vec<String> = vec![];
for word in words {
result.push(capitalize_first(word));
}
result
}
// Step 3.
@ -29,7 +31,11 @@ pub fn capitalize_words_vector(words: &[&str]) -> Vec<String> {
// Return a single string.
// ["hello", " ", "world"] -> "Hello World"
pub fn capitalize_words_string(words: &[&str]) -> String {
String::new()
let mut result = String::from("");
for word in words {
result += &capitalize_first(word);
}
result
}
#[cfg(test)]

View File

@ -6,8 +6,6 @@
// list_of_results functions.
// Execute `rustlings hint iterators3` to get some hints!
// I AM NOT DONE
#[derive(Debug, PartialEq, Eq)]
pub enum DivisionError {
NotDivisible(NotDivisibleError),
@ -22,20 +20,38 @@ pub struct NotDivisibleError {
// Calculate `a` divided by `b` if `a` is evenly divisible by `b`.
// Otherwise, return a suitable error.
pub fn divide(a: i32, b: i32) -> Result<i32, DivisionError> {}
pub fn divide(a: i32, b: i32) -> Result<i32, DivisionError> {
if b == 0 {
return Err(DivisionError::DivideByZero);
}
if a % b == 0 {
Ok(a / b)
} else {
Err(DivisionError::NotDivisible(NotDivisibleError {
dividend: a,
divisor: b,
}))
}
}
// Complete the function and return a value of the correct type so the test passes.
// Desired output: Ok([1, 11, 1426, 3])
fn result_with_list() -> () {
fn result_with_list() -> Result<Vec<i32>, DivisionError> {
let numbers = vec![27, 297, 38502, 81];
let division_results = numbers.into_iter().map(|n| divide(n, 27));
let division_results = numbers.into_iter().map(|n| divide(n, 27).unwrap());
Ok(division_results.collect())
}
// Complete the function and return a value of the correct type so the test passes.
// Desired output: [Ok(1), Ok(11), Ok(1426), Ok(3)]
fn list_of_results() -> () {
fn list_of_results() -> Vec<Result<i32, DivisionError>> {
let numbers = vec![27, 297, 38502, 81];
let division_results = numbers.into_iter().map(|n| divide(n, 27));
let division_results = numbers
.into_iter()
.map(|n| divide(n, 27))
.map(|n| Ok(n.unwrap()));
division_results.collect()
}
#[cfg(test)]

View File

@ -1,7 +1,5 @@
// iterators4.rs
// I AM NOT DONE
pub fn factorial(num: u64) -> u64 {
// Complete this function to return the factorial of num
// Do not use:
@ -12,6 +10,7 @@ pub fn factorial(num: u64) -> u64 {
// For an extra challenge, don't use:
// - recursion
// Execute `rustlings hint iterators4` for hints.
(1..=num).product()
}
#[cfg(test)]

View File

@ -10,8 +10,6 @@
//
// Make the code compile and the tests pass.
// I AM NOT DONE
use std::collections::HashMap;
#[derive(Clone, Copy, PartialEq, Eq)]
@ -34,6 +32,13 @@ fn count_for(map: &HashMap<String, Progress>, value: Progress) -> usize {
fn count_iterator(map: &HashMap<String, Progress>, value: Progress) -> usize {
// map is a hashmap with String keys and Progress values.
// map = { "variables1": Complete, "from_str": None, ... }
let mut result: usize = 0;
for v in map.values() {
if v == &value {
result += 1;
}
}
result
}
fn count_collection_for(collection: &[HashMap<String, Progress>], value: Progress) -> usize {
@ -52,6 +57,15 @@ fn count_collection_iterator(collection: &[HashMap<String, Progress>], value: Pr
// collection is a slice of hashmaps.
// collection = [{ "variables1": Complete, "from_str": None, ... },
// { "variables2": Complete, ... }, ... ]
let mut count = 0;
for map in collection {
for v in map.values() {
if v == &value {
count += 1;
}
}
}
count
}
#[cfg(test)]

View File

@ -2,13 +2,11 @@
// Make me compile without changing the function signature!
// Execute `rustlings hint strings1` for hints ;)
// I AM NOT DONE
fn main() {
let answer = current_favorite_color();
println!("My current favorite color is {}", answer);
}
fn current_favorite_color() -> String {
"blue"
"blue".to_string()
}

View File

@ -2,11 +2,9 @@
// Make me compile without changing the function signature!
// Execute `rustlings hint strings2` for hints :)
// I AM NOT DONE
fn main() {
let word = String::from("green"); // Try not changing this line :)
if is_a_color_word(word) {
if is_a_color_word(&word) {
println!("That is a color word I know!");
} else {
println!("That is not a color word I know.");

View File

@ -1,13 +1,13 @@
// structs1.rs
// Address all the TODOs to make the tests pass!
// I AM NOT DONE
struct ColorClassicStruct {
// TODO: Something goes here
name: String,
hex: String,
}
struct ColorTupleStruct(/* TODO: Something goes here */);
struct ColorTupleStruct(String, String);
#[derive(Debug)]
struct UnitStruct;
@ -19,7 +19,10 @@ mod tests {
#[test]
fn classic_c_structs() {
// TODO: Instantiate a classic c struct!
// let green =
let green = ColorClassicStruct {
name: String::from("green"),
hex: String::from("#00FF00"),
};
assert_eq!(green.name, "green");
assert_eq!(green.hex, "#00FF00");
@ -28,7 +31,7 @@ mod tests {
#[test]
fn tuple_structs() {
// TODO: Instantiate a tuple struct!
// let green =
let green = ("green".to_string(), "#00FF00".to_string());
assert_eq!(green.0, "green");
assert_eq!(green.1, "#00FF00");
@ -37,7 +40,7 @@ mod tests {
#[test]
fn unit_structs() {
// TODO: Instantiate a unit struct!
// let unit_struct =
let unit_struct = UnitStruct;
let message = format!("{:?}s are fun!", unit_struct);
assert_eq!(message, "UnitStructs are fun!");

View File

@ -1,8 +1,6 @@
// structs2.rs
// Address all the TODOs to make the tests pass!
// I AM NOT DONE
#[derive(Debug)]
struct Order {
name: String,
@ -34,7 +32,11 @@ mod tests {
fn your_order() {
let order_template = create_order_template();
// TODO: Create your own order using the update syntax and template above!
// let your_order =
let your_order = Order {
name: String::from("Hacker in Rust"),
count: 1,
..order_template
};
assert_eq!(your_order.name, "Hacker in Rust");
assert_eq!(your_order.year, order_template.year);
assert_eq!(your_order.made_by_phone, order_template.made_by_phone);

View File

@ -4,8 +4,6 @@
// Make the code compile and the tests pass!
// If you have issues execute `rustlings hint structs3`
// I AM NOT DONE
#[derive(Debug)]
struct Package {
sender_country: String,
@ -16,7 +14,7 @@ struct Package {
impl Package {
fn new(sender_country: String, recipient_country: String, weight_in_grams: i32) -> Package {
if weight_in_grams <= 0 {
// Something goes here...
panic!("weight_in_grams must larger than 0!");
} else {
return Package {
sender_country,
@ -26,12 +24,12 @@ impl Package {
}
}
fn is_international(&self) -> ??? {
// Something goes here...
fn is_international(&self) -> bool {
self.sender_country != self.recipient_country
}
fn get_fees(&self, cents_per_gram: i32) -> ??? {
// Something goes here...
fn get_fees(&self, cents_per_gram: i32) -> i32 {
self.weight_in_grams * cents_per_gram
}
}
@ -73,7 +71,7 @@ mod tests {
let sender_country = String::from("Spain");
let recipient_country = String::from("Spain");
let cents_per_gram = ???;
let cents_per_gram = 3;
let package = Package::new(sender_country, recipient_country, 1500);

View File

@ -6,12 +6,10 @@
// This test has a problem with it -- make the test compile! Make the test
// pass! Make the test fail! Execute `rustlings hint tests1` for hints :)
// I AM NOT DONE
#[cfg(test)]
mod tests {
#[test]
fn you_can_assert() {
assert!();
assert!(true);
}
}

View File

@ -2,12 +2,10 @@
// This test has a problem with it -- make the test compile! Make the test
// pass! Make the test fail! Execute `rustlings hint tests2` for hints :)
// I AM NOT DONE
#[cfg(test)]
mod tests {
#[test]
fn you_can_assert_eq() {
assert_eq!();
assert_eq!(true, true);
}
}

View File

@ -4,8 +4,6 @@
// we expect to get when we call `is_even(5)`.
// Execute `rustlings hint tests3` for hints :)
// I AM NOT DONE
pub fn is_even(num: i32) -> bool {
num % 2 == 0
}
@ -16,11 +14,11 @@ mod tests {
#[test]
fn is_true_when_even() {
assert!();
assert!(is_even(2));
}
#[test]
fn is_false_when_odd() {
assert!();
assert!(is_even(3) == false);
}
}

View File

@ -6,26 +6,26 @@
// of "waiting..." and the program ends without timing out when running,
// you've got it :)
// I AM NOT DONE
use std::sync::Arc;
use std::sync::{Arc, Mutex};
use std::thread;
use std::time::Duration;
#[derive(Clone, Copy)]
struct JobStatus {
jobs_completed: u32,
}
fn main() {
let status = Arc::new(JobStatus { jobs_completed: 0 });
let status_shared = status.clone();
thread::spawn(move || {
for _ in 0..10 {
thread::sleep(Duration::from_millis(250));
status_shared.jobs_completed += 1;
}
});
while status.jobs_completed < 10 {
let status = Arc::new(Mutex::new(JobStatus { jobs_completed: 0 }));
for _ in 0..10 {
let status_shared = Arc::clone(&status);
thread::spawn(move || {
// thread::sleep(Duration::from_millis(250));
status_shared.lock().unwrap().jobs_completed += 1;
println!("{}", status_shared.lock().unwrap().jobs_completed);
});
}
while status.lock().unwrap().jobs_completed < 10 {
println!("waiting... ");
thread::sleep(Duration::from_millis(500));
}

View File

@ -8,14 +8,14 @@
// which appends "Bar" to any object
// implementing this trait.
// I AM NOT DONE
trait AppendBar {
fn append_bar(self) -> Self;
}
impl AppendBar for String {
//Add your code here
fn append_bar(self) -> Self {
self + "Bar"
}
}
fn main() {

View File

@ -10,13 +10,18 @@
// No boiler plate code this time,
// you can do this!
// I AM NOT DONE
trait AppendBar {
fn append_bar(self) -> Self;
}
//TODO: Add your code here
impl AppendBar for Vec<String> {
fn append_bar(mut self) -> Self {
self.push(String::from("Bar"));
self
}
}
#[cfg(test)]
mod tests {

View File

@ -6,9 +6,8 @@
// even after you already figured it out. If you got everything working and
// feel ready for the next exercise, remove the `I AM NOT DONE` comment below.
// I AM NOT DONE
fn main() {
x = 5;
let x: i32 = 5;
println!("x has the value {}", x);
}

View File

@ -1,10 +1,9 @@
// variables2.rs
// Make me compile! Execute the command `rustlings hint variables2` if you want a hint :)
// I AM NOT DONE
fn main() {
let x;
let x = 10;
if x == 10 {
println!("Ten!");
} else {

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@ -1,10 +1,9 @@
// variables3.rs
// Make me compile! Execute the command `rustlings hint variables3` if you want a hint :)
// I AM NOT DONE
fn main() {
let x = 3;
let mut x = 3;
println!("Number {}", x);
x = 5; // don't change this line
println!("Number {}", x);

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@ -1,9 +1,8 @@
// variables4.rs
// Make me compile! Execute the command `rustlings hint variables4` if you want a hint :)
// I AM NOT DONE
fn main() {
let x: i32;
let x: i32 = 0;
println!("Number {}", x);
}

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@ -1,11 +1,10 @@
// variables5.rs
// Make me compile! Execute the command `rustlings hint variables5` if you want a hint :)
// I AM NOT DONE
fn main() {
let number = "T-H-R-E-E"; // don't change this line
println!("Spell a Number : {}", number);
number = 3;
let number = 3;
println!("Number plus two is : {}", number + 2);
}

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@ -1,9 +1,8 @@
// variables6.rs
// Make me compile! Execute the command `rustlings hint variables6` if you want a hint :)
// I AM NOT DONE
const NUMBER = 3;
const NUMBER: i32 = 3;
fn main() {
println!("Number {}", NUMBER);
}