My solution to rustlings course

error handling
enums.
strings
modules
hashmaps
quiz2

options

error handling

Error handling
This commit is contained in:
Marco 2023-09-10 18:38:07 +02:00
parent bc3808cf29
commit cb71bd7583
57 changed files with 191 additions and 178 deletions

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@ -13,7 +13,6 @@
// Execute `rustlings hint intro1` or use the `hint` watch subcommand for a
// hint.
// I AM NOT DONE
fn main() {
println!("Hello and");

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@ -5,8 +5,7 @@
// Execute `rustlings hint intro2` or use the `hint` watch subcommand for a
// hint.
// I AM NOT DONE
fn main() {
printline!("Hello there!")
let par: &str = "world";
println!("Hello {}!", par);
}

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@ -5,9 +5,7 @@
// Execute `rustlings hint variables1` or use the `hint` watch subcommand for a
// hint.
// I AM NOT DONE
fn main() {
x = 5;
let x = 5;
println!("x has the value {}", x);
}

View File

@ -3,10 +3,8 @@
// Execute `rustlings hint variables2` or use the `hint` watch subcommand for a
// hint.
// I AM NOT DONE
fn main() {
let x;
let x = 5;
if x == 10 {
println!("x is ten!");
} else {

View File

@ -3,9 +3,8 @@
// Execute `rustlings hint variables3` or use the `hint` watch subcommand for a
// hint.
// I AM NOT DONE
fn main() {
let x: i32;
let x: i32 = 1;
println!("Number {}", x);
}

View File

@ -3,10 +3,9 @@
// Execute `rustlings hint variables4` or use the `hint` watch subcommand for 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);

View File

@ -3,11 +3,9 @@
// Execute `rustlings hint variables5` or use the `hint` watch subcommand for 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; // don't rename this variable
let number = 3; // don't rename this variable
println!("Number plus two is : {}", number + 2);
}

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@ -3,9 +3,7 @@
// Execute `rustlings hint variables6` or use the `hint` watch subcommand for a
// hint.
// I AM NOT DONE
const NUMBER = 3;
const NUMBER :u8 = 3;
fn main() {
println!("Number {}", NUMBER);
}

View File

@ -3,8 +3,8 @@
// Execute `rustlings hint functions1` or use the `hint` watch subcommand for a
// hint.
// I AM NOT DONE
fn main() {
call_me();
}
fn call_me() {}

View File

@ -3,13 +3,11 @@
// Execute `rustlings hint functions2` or use the `hint` watch subcommand for a
// hint.
// 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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@ -3,10 +3,9 @@
// Execute `rustlings hint functions3` or use the `hint` watch subcommand for a
// hint.
// I AM NOT DONE
fn main() {
call_me();
call_me(1000);
}
fn call_me(num: u32) {

View File

@ -8,14 +8,13 @@
// Execute `rustlings hint functions4` or use the `hint` watch subcommand for a
// hint.
// 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: u32) -> u32 {
if is_even(price) {
price - 10
} else {
@ -23,6 +22,6 @@ fn sale_price(price: i32) -> {
}
}
fn is_even(num: i32) -> bool {
fn is_even(num: u32) -> bool {
num % 2 == 0
}

View File

@ -3,7 +3,6 @@
// Execute `rustlings hint functions5` or use the `hint` watch subcommand for a
// hint.
// I AM NOT DONE
fn main() {
let answer = square(3);
@ -11,5 +10,5 @@ fn main() {
}
fn square(num: i32) -> i32 {
num * num;
num * num
}

View File

@ -2,13 +2,16 @@
//
// Execute `rustlings hint if1` or use the `hint` watch subcommand for a hint.
// I AM NOT DONE
pub fn bigger(a: i32, b: i32) -> i32 {
// Complete this function to return the bigger number!
// Do not use:
// - another function call
// - additional variables
if a > b {
return a;
}
b
}
// Don't mind this for now :)

View File

@ -5,13 +5,14 @@
//
// Execute `rustlings hint if2` or use the `hint` watch subcommand for a hint.
// I AM NOT DONE
pub fn foo_if_fizz(fizzish: &str) -> &str {
if fizzish == "fizz" {
"foo"
} else if fizzish == "fuzz" {
"bar"
} else {
1
"baz"
}
}

View File

@ -2,17 +2,16 @@
//
// Execute `rustlings hint if3` or use the `hint` watch subcommand for a hint.
// I AM NOT DONE
pub fn animal_habitat(animal: &str) -> &'static str {
let identifier = if animal == "crab" {
1
} else if animal == "gopher" {
2.0
2
} else if animal == "snake" {
3
} else {
"Unknown"
0
};
// DO NOT CHANGE THIS STATEMENT BELOW

View File

@ -3,7 +3,6 @@
// 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`)
@ -13,7 +12,7 @@ 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

@ -3,7 +3,6 @@
// 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`)
@ -19,7 +18,7 @@ fn main() {
println!("Neither alphabetic nor numeric!");
}
let // Finish this line like the example! What's your favorite character?
let your_character = '1'; // 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

@ -5,10 +5,9 @@
// Execute `rustlings hint primitive_types3` or use the `hint` watch subcommand
// for a hint.
// I AM NOT DONE
fn main() {
let a = ???
let a = [1;1000];
if a.len() >= 100 {
println!("Wow, that's a big array!");

View File

@ -5,13 +5,12 @@
// Execute `rustlings hint primitive_types4` or use the `hint` watch subcommand
// for a hint.
// 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)
}

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@ -5,11 +5,10 @@
// Execute `rustlings hint primitive_types5` or use the `hint` watch subcommand
// for a hint.
// 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);
}

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@ -6,13 +6,12 @@
// Execute `rustlings hint primitive_types6` or use the `hint` watch subcommand
// for a hint.
// 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!")

View File

@ -7,11 +7,10 @@
//
// Execute `rustlings hint vecs1` or use the `hint` watch subcommand for a hint.
// 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 = vec![a[0],a[1],a[2],a[3]]; // TODO: declare your vector here with the macro for vectors
(a, v)
}

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@ -7,13 +7,11 @@
//
// Execute `rustlings hint vecs2` or use the `hint` watch subcommand for a hint.
// I AM NOT DONE
fn vec_loop(mut v: Vec<i32>) -> Vec<i32> {
for element in v.iter_mut() {
// TODO: Fill this up so that each element in the Vec `v` is
// multiplied by 2.
???
*element *= 2;
}
// At this point, `v` should be equal to [4, 8, 12, 16, 20].
@ -21,11 +19,13 @@ fn vec_loop(mut v: Vec<i32>) -> Vec<i32> {
}
fn vec_map(v: &Vec<i32>) -> Vec<i32> {
v.iter().map(|element| {
// TODO: Do the same thing as above - but instead of mutating the
// Vec, you can just return the new number!
???
}).collect()
v.iter()
.map(|element| {
// TODO: Do the same thing as above - but instead of mutating the
// Vec, you can just return the new number!
element * 2
})
.collect()
}
#[cfg(test)]

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@ -3,7 +3,6 @@
// Execute `rustlings hint move_semantics1` or use the `hint` watch subcommand
// for a hint.
// I AM NOT DONE
#[test]
fn main() {
@ -15,7 +14,7 @@ fn main() {
}
fn fill_vec(vec: Vec<i32>) -> Vec<i32> {
let vec = vec;
let mut vec = vec;
vec.push(88);

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@ -5,20 +5,18 @@
// Execute `rustlings hint move_semantics2` or use the `hint` watch subcommand
// for a hint.
// I AM NOT DONE
#[test]
fn main() {
let vec0 = vec![22, 44, 66];
let mut vec1 = fill_vec(vec0);
let mut vec1 = fill_vec(&vec0);
assert_eq!(vec0, vec![22, 44, 66]);
assert_eq!(vec1, vec![22, 44, 66, 88]);
}
fn fill_vec(vec: Vec<i32>) -> Vec<i32> {
let mut vec = vec;
fn fill_vec(vec: &Vec<i32>) -> Vec<i32> {
let mut vec = vec.clone();
vec.push(88);

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@ -6,18 +6,16 @@
// Execute `rustlings hint move_semantics3` or use the `hint` watch subcommand
// for a hint.
// I AM NOT DONE
#[test]
fn main() {
let vec0 = vec![22, 44, 66];
let mut vec1 = fill_vec(vec0);
let vec1 = fill_vec(vec0);
assert_eq!(vec1, vec![22, 44, 66, 88]);
}
fn fill_vec(vec: Vec<i32>) -> Vec<i32> {
fn fill_vec(mut vec: Vec<i32>) -> Vec<i32> {
vec.push(88);
vec

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@ -7,21 +7,17 @@
// Execute `rustlings hint move_semantics4` or use the `hint` watch subcommand
// for a hint.
// I AM NOT DONE
#[test]
fn main() {
let vec0 = vec![22, 44, 66];
let mut vec1 = fill_vec(vec0);
let vec1 = fill_vec();
assert_eq!(vec1, vec![22, 44, 66, 88]);
}
// `fill_vec()` no longer takes `vec: Vec<i32>` as argument - don't change this!
fn fill_vec() -> Vec<i32> {
let mut vec = vec![22, 44, 66];
// Instead, let's create and fill the Vec in here - how do you do that?
let mut vec = vec;
vec.push(88);

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@ -6,14 +6,12 @@
// Execute `rustlings hint move_semantics5` or use the `hint` watch subcommand
// for a hint.
// I AM NOT DONE
#[test]
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);
}

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@ -5,24 +5,23 @@
// Execute `rustlings hint move_semantics6` or use the `hint` watch subcommand
// for a hint.
// I AM NOT DONE
fn main() {
let data = "Rust is great!".to_string();
get_char(data);
let letter = get_char(&data);
println!("Letter is {}", letter);
string_uppercase(&data);
string_uppercase(data);
}
// Should not take ownership
fn get_char(data: String) -> char {
fn get_char(data: &String) -> char {
data.chars().last().unwrap()
}
// Should take ownership
fn string_uppercase(mut data: &String) {
data = &data.to_uppercase();
fn string_uppercase(mut data: String) {
data = data.to_uppercase();
println!("{}", data);
}

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@ -5,13 +5,13 @@
// Execute `rustlings hint structs1` or use the `hint` watch subcommand for a
// hint.
// I AM NOT DONE
struct ColorClassicStruct {
// TODO: Something goes here
red: u8,
green: u8,
blue: u8,
}
struct ColorTupleStruct(/* TODO: Something goes here */);
struct ColorTupleStruct(u8,u8,u8);
#[derive(Debug)]
struct UnitLikeStruct;
@ -23,7 +23,7 @@ mod tests {
#[test]
fn classic_c_structs() {
// TODO: Instantiate a classic c struct!
// let green =
let green = ColorClassicStruct{red: 0, green: 255, blue: 0};
assert_eq!(green.red, 0);
assert_eq!(green.green, 255);
@ -33,7 +33,7 @@ mod tests {
#[test]
fn tuple_structs() {
// TODO: Instantiate a tuple struct!
// let green =
let green = (0,255,0);
assert_eq!(green.0, 0);
assert_eq!(green.1, 255);
@ -43,7 +43,7 @@ mod tests {
#[test]
fn unit_structs() {
// TODO: Instantiate a unit-like struct!
// let unit_like_struct =
let unit_like_struct = UnitLikeStruct;
let message = format!("{:?}s are fun!", unit_like_struct);
assert_eq!(message, "UnitLikeStructs are fun!");

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@ -5,8 +5,6 @@
// Execute `rustlings hint structs2` or use the `hint` watch subcommand for a
// hint.
// I AM NOT DONE
#[derive(Debug)]
struct Order {
name: String,
@ -38,7 +36,11 @@ 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: "Hacker in Rust".to_string(),
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);

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@ -7,7 +7,6 @@
// Execute `rustlings hint structs3` or use the `hint` watch subcommand for a
// hint.
// I AM NOT DONE
#[derive(Debug)]
struct Package {
@ -31,12 +30,14 @@ impl Package {
}
}
fn is_international(&self) -> ??? {
fn is_international(&self) -> bool {
// Something goes here...
return self.sender_country != self.recipient_country;
}
fn get_fees(&self, cents_per_gram: u32) -> ??? {
fn get_fees(&self, cents_per_gram: u32) -> u32 {
// Something goes here...
self.weight_in_grams * cents_per_gram
}
}

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@ -2,11 +2,14 @@
//
// No hints this time! ;)
// 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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@ -3,11 +3,14 @@
// Execute `rustlings hint enums2` or use the `hint` watch subcommand for a
// hint.
// I AM NOT DONE
#[derive(Debug)]
enum Message {
// TODO: define the different variants used below
Move { x: u8, y: u8 },
Echo(String),
ChangeColor(u8, u8, u8),
Quit,
}
impl Message {

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@ -5,10 +5,12 @@
// Execute `rustlings hint enums3` or use the `hint` watch subcommand for a
// hint.
// 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 {
@ -44,6 +46,20 @@ impl State {
// TODO: create a match expression to process the different message variants
// Remember: When passing a tuple as a function argument, you'll need extra parentheses:
// fn function((t, u, p, l, e))
match message {
Message::ChangeColor(r, g, b) => {
self.color = (r, g, b);
}
Message::Echo(m) => {
self.message = m;
}
Message::Move(Point { x, y }) => {
self.position = Point { x, y };
}
Message::Quit => {
self.quit = true;
}
}
}
}

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@ -5,7 +5,6 @@
// Execute `rustlings hint strings1` or use the `hint` watch subcommand for a
// hint.
// I AM NOT DONE
fn main() {
let answer = current_favorite_color();
@ -13,5 +12,5 @@ fn main() {
}
fn current_favorite_color() -> String {
"blue"
"blue".to_string()
}

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@ -5,11 +5,9 @@
// Execute `rustlings hint strings2` or use the `hint` watch subcommand for a
// hint.
// 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.");

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@ -3,21 +3,21 @@
// Execute `rustlings hint strings3` or use the `hint` watch subcommand for a
// hint.
// I AM NOT DONE
fn trim_me(input: &str) -> String {
// TODO: Remove whitespace from both ends of a string!
???
input.trim().to_string()
}
fn compose_me(input: &str) -> String {
// TODO: Add " world!" to the string! There's multiple ways to do this!
???
let return_string = input.to_string() + " world!";
return_string
}
fn replace_me(input: &str) -> String {
// TODO: Replace "cars" in the string with "balloons"!
???
input.replace("cars", "balloons")
}
#[cfg(test)]

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@ -7,7 +7,6 @@
//
// No hints this time!
// I AM NOT DONE
fn string_slice(arg: &str) {
println!("{}", arg);
@ -17,14 +16,14 @@ 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_slice("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());
}

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@ -3,7 +3,6 @@
// Execute `rustlings hint modules1` or use the `hint` watch subcommand for a
// hint.
// I AM NOT DONE
mod sausage_factory {
// Don't let anybody outside of this module see this!
@ -11,7 +10,7 @@ mod sausage_factory {
String::from("Ginger")
}
fn make_sausage() {
pub fn make_sausage() {
get_secret_recipe();
println!("sausage!");
}

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@ -7,12 +7,11 @@
// Execute `rustlings hint modules2` or use the `hint` watch subcommand for a
// hint.
// 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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@ -8,10 +8,9 @@
// Execute `rustlings hint modules3` or use the `hint` watch subcommand for a
// hint.
// I AM NOT DONE
// TODO: Complete this use statement
use ???
use std::time::*;
fn main() {
match SystemTime::now().duration_since(UNIX_EPOCH) {

View File

@ -11,17 +11,18 @@
// Execute `rustlings hint hashmaps1` or use the `hint` watch subcommand for a
// hint.
// 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::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"), 3);
basket.insert(String::from("cherry"),1);
basket
}

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@ -14,7 +14,6 @@
// Execute `rustlings hint hashmaps2` or use the `hint` watch subcommand for a
// hint.
// I AM NOT DONE
use std::collections::HashMap;
@ -40,6 +39,7 @@ fn fruit_basket(basket: &mut HashMap<Fruit, u32>) {
// TODO: Insert new fruits if they are not already present in the
// basket. Note that you are not allowed to put any type of fruit that's
// already present!
basket.entry(fruit).or_insert(1);
}
}
@ -81,7 +81,7 @@ mod tests {
let count = basket.values().sum::<u32>();
assert!(count > 11);
}
#[test]
fn all_fruit_types_in_basket() {
let mut basket = get_fruit_basket();

View File

@ -14,8 +14,6 @@
// Execute `rustlings hint hashmaps3` or use the `hint` watch subcommand for a
// hint.
// I AM NOT DONE
use std::collections::HashMap;
// A structure to store the goal details of a team.
@ -39,6 +37,22 @@ fn build_scores_table(results: String) -> HashMap<String, Team> {
// will be the number of goals conceded from team_2, and similarly
// goals scored by team_2 will be the number of goals conceded by
// team_1.
let team_1 = scores.entry(team_1_name).or_insert(Team {
goals_scored: 0,
goals_conceded: 0,
});
(*team_1).goals_conceded += team_2_score;
(*team_1).goals_scored += team_1_score;
let team_2 = scores.entry(team_2_name).or_insert(Team {
goals_scored: 0,
goals_conceded: 0,
});
(*team_2).goals_conceded += team_1_score;
(*team_2).goals_scored += team_2_score;
}
scores
}

View File

@ -3,8 +3,6 @@
// Execute `rustlings hint options1` or use the `hint` watch subcommand for a
// hint.
// I AM NOT DONE
// This function returns how much icecream there is left in the fridge.
// If it's before 10PM, there's 5 pieces left. At 10PM, someone eats them
// all, so there'll be no more left :(
@ -13,7 +11,13 @@ fn maybe_icecream(time_of_day: u16) -> Option<u16> {
// value of 0 The Option output should gracefully handle cases where
// time_of_day > 23.
// TODO: Complete the function body - remember to return an Option!
???
if time_of_day > 23 {
return None;
}
if time_of_day > 21 {
return Some(0);
}
Some(5)
}
#[cfg(test)]
@ -33,7 +37,7 @@ mod tests {
fn raw_value() {
// TODO: Fix this test. How do you get at the value contained in the
// Option?
let icecreams = maybe_icecream(12);
let icecreams = maybe_icecream(12).unwrap_or(0);
assert_eq!(icecreams, 5);
}
}

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@ -3,8 +3,6 @@
// Execute `rustlings hint options2` or use the `hint` watch subcommand for a
// hint.
// I AM NOT DONE
#[cfg(test)]
mod tests {
#[test]
@ -13,7 +11,7 @@ mod tests {
let optional_target = Some(target);
// TODO: Make this an if let statement whose value is "Some" type
word = optional_target {
if let Some(word) = optional_target {
assert_eq!(word, target);
}
}
@ -32,7 +30,8 @@ mod tests {
// 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.pop() {
while let Some(Some(integer)) = optional_integers.pop() {
println!("resulting integer: {}", integer);
assert_eq!(integer, cursor);
cursor -= 1;
}

View File

@ -3,8 +3,6 @@
// Execute `rustlings hint options3` or use the `hint` watch subcommand for a
// hint.
// I AM NOT DONE
struct Point {
x: i32,
y: i32,
@ -14,7 +12,7 @@ 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),
_ => panic!("no match!"),
}
y; // Fix without deleting this line.

View File

@ -9,14 +9,12 @@
// Execute `rustlings hint errors1` or use the `hint` watch subcommand for a
// hint.
// 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.is_empty() {
// Empty names aren't allowed.
None
Err("`name` was empty; it must be nonempty.".into())
} else {
Some(format!("Hi! My name is {}", name))
Ok(format!("Hi! My name is {}", name))
}
}

View File

@ -19,15 +19,12 @@
// Execute `rustlings hint errors2` or use the `hint` watch subcommand for a
// hint.
// 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)
}

View File

@ -7,11 +7,9 @@
// Execute `rustlings hint errors3` or use the `hint` watch subcommand for a
// hint.
// I AM NOT DONE
use std::num::ParseIntError;
fn main() {
fn main() -> Result<(), ParseIntError> {
let mut tokens = 100;
let pretend_user_input = "8";
@ -23,6 +21,7 @@ fn main() {
tokens -= cost;
println!("You now have {} tokens.", tokens);
}
Ok(())
}
pub fn total_cost(item_quantity: &str) -> Result<i32, ParseIntError> {

View File

@ -3,8 +3,6 @@
// Execute `rustlings hint errors4` or use the `hint` watch subcommand for a
// hint.
// I AM NOT DONE
#[derive(PartialEq, Debug)]
struct PositiveNonzeroInteger(u64);
@ -16,7 +14,13 @@ enum CreationError {
impl PositiveNonzeroInteger {
fn new(value: i64) -> Result<PositiveNonzeroInteger, CreationError> {
// Hmm... Why is this always returning an Ok value?
if value < 0 {
return Err(CreationError::Negative);
}
if value == 0 {
return Err(CreationError::Zero);
}
Ok(PositiveNonzeroInteger(value as u64))
}
}

View File

@ -22,14 +22,12 @@
// Execute `rustlings hint errors5` or use the `hint` watch subcommand for a
// hint.
// 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<(), Box<dyn ???>> {
fn main() -> Result<(), Box<dyn error::Error>> {
let pretend_user_input = "42";
let x: i64 = pretend_user_input.parse()?;
println!("output={:?}", PositiveNonzeroInteger::new(x)?);

View File

@ -9,8 +9,6 @@
// Execute `rustlings hint errors6` or use the `hint` watch subcommand for a
// hint.
// I AM NOT DONE
use std::num::ParseIntError;
// This is a custom error type that we will be using in `parse_pos_nonzero()`.
@ -25,13 +23,17 @@ impl ParsePosNonzeroError {
ParsePosNonzeroError::Creation(err)
}
// TODO: add another error conversion function here.
// fn from_parseint...
fn from_parseint(err: ParseIntError) -> ParsePosNonzeroError {
ParsePosNonzeroError::ParseInt(err)
}
}
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();
let x_opt = s.parse();
let x = x_opt.map_err(ParsePosNonzeroError::from_parseint)?;
PositiveNonzeroInteger::new(x).map_err(ParsePosNonzeroError::from_creation)
}

View File

@ -13,10 +13,15 @@
//
// No hints this time ;)
// I AM NOT DONE
// Put your function here!
// fn calculate_price_of_apples {
fn calculate_price_of_apples(apples: u64) -> u64 {
if apples > 40 {
apples
} else {
apples * 2
}
}
// Don't modify this function!
#[test]

View File

@ -20,8 +20,6 @@
//
// No hints this time!
// I AM NOT DONE
pub enum Command {
Uppercase,
Trim,
@ -32,11 +30,22 @@ mod my_module {
use super::Command;
// TODO: Complete the function signature!
pub fn transformer(input: ???) -> ??? {
pub fn transformer(input: Vec<(String, Command)>) -> Vec<String> {
// TODO: Complete the output declaration!
let mut output: ??? = vec![];
let mut output: Vec<String> = vec![];
for (string, command) in input.iter() {
// TODO: Complete the function body. You can do it!
match command {
Command::Trim => output.push(string.trim().to_string()),
Command::Uppercase => output.push(string.to_uppercase()),
Command::Append(size) => {
let mut buf: String = string.to_owned();
for n in 0..*size {
buf += "bar";
}
output.push(buf)
}
}
}
output
}
@ -45,12 +54,12 @@ mod my_module {
#[cfg(test)]
mod tests {
// TODO: What do we need to import to have `transformer` in scope?
use ???;
use super::Command;
use crate::my_module;
#[test]
fn it_works() {
let output = transformer(vec![
let output = my_module::transformer(vec![
("hello".into(), Command::Uppercase),
(" all roads lead to rome! ".into(), Command::Trim),
("foo".into(), Command::Append(1)),