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https://github.com/rust-lang/rustlings.git
synced 2026-01-11 05:09:19 +00:00
did some more
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9e3329d277
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@ -11,17 +11,17 @@
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// Execute the command `rustlings hint hashmap1` if you need
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// hints.
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// I AM NOT DONE
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use std::collections::HashMap;
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fn fruit_basket() -> HashMap<String, u32> {
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let mut basket = // TODO: declare your hash map here.
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let mut basket = HashMap::new();// TODO: declare your hash map here.
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// Two bananas are already given for you :)
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basket.insert(String::from("banana"), 2);
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// TODO: Put more fruits in your basket here.
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basket.insert(String::from("apple"), 2);
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basket.insert(String::from("mango"), 1);
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basket
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}
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@ -12,8 +12,6 @@
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// Execute the command `rustlings hint hashmap2` if you need
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// hints.
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// I AM NOT DONE
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use std::collections::HashMap;
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#[derive(Hash, PartialEq, Eq)]
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@ -38,6 +36,9 @@ fn fruit_basket(basket: &mut HashMap<Fruit, u32>) {
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// TODO: Put new fruits if not already present. Note that you
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// are not allowed to put any type of fruit that's already
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// present!
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if basket.get(&fruit) == None {
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basket.insert(fruit, 1);
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}
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}
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}
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@ -4,11 +4,9 @@
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// Make me compile and pass the test!
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// Execute the command `rustlings hint vec1` if you need hints.
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// I AM NOT DONE
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fn array_and_vec() -> ([i32; 4], Vec<i32>) {
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let a = [10, 20, 30, 40]; // a plain array
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let v = // TODO: declare your vector here with the macro for vectors
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let v = vec![10, 20, 30, 40];// TODO: declare your vector here with the macro for vectors
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(a, v)
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}
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@ -7,12 +7,11 @@
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// Execute the command `rustlings hint vec2` if you need
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// hints.
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// I AM NOT DONE
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fn vec_loop(mut v: Vec<i32>) -> Vec<i32> {
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for i in v.iter_mut() {
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// TODO: Fill this up so that each element in the Vec `v` is
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// multiplied by 2.
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*i = *i * 2;
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}
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// At this point, `v` should be equal to [4, 8, 12, 16, 20].
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@ -5,14 +5,11 @@
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// construct to `Option` that can be used to express error conditions. Let's use it!
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// Execute `rustlings hint errors1` for hints!
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// I AM NOT DONE
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pub fn generate_nametag_text(name: String) -> Option<String> {
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pub fn generate_nametag_text(name: String) -> Result<String, String> {
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if name.len() > 0 {
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Some(format!("Hi! My name is {}", name))
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Ok(format!("Hi! My name is {}", name))
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} else {
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// Empty names aren't allowed.
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None
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Err(String::from("`name` was empty; it must be nonempty."))
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}
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}
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@ -16,14 +16,20 @@
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// There are at least two ways to implement this that are both correct-- but
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// one is a lot shorter! Execute `rustlings hint errors2` for hints to both ways.
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// I AM NOT DONE
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use std::num::ParseIntError;
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pub fn total_cost(item_quantity: &str) -> Result<i32, ParseIntError> {
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let processing_fee = 1;
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let cost_per_item = 5;
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// method one
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//let mut qty = item_quantity.parse::<i32>()?;
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// method two
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let qty = item_quantity.parse::<i32>();
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let mut qty = match qty {
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Ok(number) => number,
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Err(e) => return Err(e),
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};
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Ok(qty * cost_per_item + processing_fee)
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}
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@ -4,15 +4,18 @@
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// Why not? What should we do to fix it?
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// Execute `rustlings hint errors3` for hints!
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// I AM NOT DONE
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use std::num::ParseIntError;
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fn main() {
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let mut tokens = 100;
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let pretend_user_input = "8";
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let cost = total_cost(pretend_user_input)?;
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let cost = total_cost(pretend_user_input);
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let mut cost = match cost {
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Ok(number) => number,
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Err(e) => panic!(e),
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};
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if cost > tokens {
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println!("You can't afford that many!");
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@ -1,8 +1,6 @@
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// errors4.rs
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// Make this test pass! Execute `rustlings hint errors4` for hints :)
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// I AM NOT DONE
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#[derive(PartialEq, Debug)]
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struct PositiveNonzeroInteger(u64);
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@ -14,6 +12,13 @@ enum CreationError {
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impl PositiveNonzeroInteger {
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fn new(value: i64) -> Result<PositiveNonzeroInteger, CreationError> {
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if value == 0 {
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return Err(CreationError::Zero)
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} else if value < 0 {
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return Err(CreationError::Negative)
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}
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Ok(PositiveNonzeroInteger(value as u64))
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}
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}
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@ -4,14 +4,12 @@
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// It won't compile right now! Why?
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// Execute `rustlings hint errors5` for hints!
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// I AM NOT DONE
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use std::error;
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use std::fmt;
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use std::num::ParseIntError;
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// TODO: update the return type of `main()` to make this compile.
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fn main() -> Result<(), ParseIntError> {
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fn main() -> Result<(), Box<dyn error::Error>> {
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let pretend_user_input = "42";
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let x: i64 = pretend_user_input.parse()?;
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println!("output={:?}", PositiveNonzeroInteger::new(x)?);
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@ -8,8 +8,6 @@
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// Make these tests pass! Execute `rustlings hint errors6` for hints :)
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// I AM NOT DONE
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use std::num::ParseIntError;
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// This is a custom error type that we will be using in `parse_pos_nonzero()`.
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@ -21,6 +19,13 @@ enum ParsePosNonzeroError {
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impl ParsePosNonzeroError {
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// TODO: add another error conversion function here.
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fn from_creation(err: CreationError) -> ParsePosNonzeroError {
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ParsePosNonzeroError::Creation(err)
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}
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fn from_parsing(err: ParseIntError) -> ParsePosNonzeroError {
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ParsePosNonzeroError::ParseInt(err)
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}
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}
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fn parse_pos_nonzero(s: &str)
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@ -28,7 +33,12 @@ fn parse_pos_nonzero(s: &str)
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{
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// TODO: change this to return an appropriate error instead of panicking
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// when `parse()` returns an error.
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let x: i64 = s.parse().unwrap();
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let x: Result<i64, ParseIntError> = s.parse();
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let mut x: i64 = match x {
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Ok(number) => number,
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Err(e) => return Err(ParsePosNonzeroError::ParseInt(e)),
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};
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PositiveNonzeroInteger::new(x)
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.map_err(ParsePosNonzeroError::from_creation)
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}
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@ -3,9 +3,7 @@
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// Execute `rustlings hint generics1` for hints!
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// I AM NOT DONE
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fn main() {
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let mut shopping_list: Vec<?> = Vec::new();
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let mut shopping_list: Vec<&str> = Vec::new();
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shopping_list.push("milk");
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}
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@ -3,14 +3,12 @@
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// Execute `rustlings hint generics2` for hints!
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// I AM NOT DONE
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struct Wrapper {
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value: u32,
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struct Wrapper<T> {
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value: T,
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}
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impl Wrapper {
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pub fn new(value: u32) -> Self {
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impl<T> Wrapper<T> {
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pub fn new(value: T) -> Self {
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Wrapper { value }
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}
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}
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@ -10,15 +10,13 @@
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// Execute 'rustlings hint generics3' for hints!
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// I AM NOT DONE
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pub struct ReportCard {
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pub grade: f32,
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pub struct ReportCard<T> {
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pub grade: T,
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pub student_name: String,
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pub student_age: u8,
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}
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impl ReportCard {
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impl<T: std::fmt::Display> ReportCard<T> {
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pub fn print(&self) -> String {
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format!("{} ({}) - achieved a grade of {}",
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&self.student_name, &self.student_age, &self.grade)
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fn generate_alphabetic_report_card() {
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// TODO: Make sure to change the grade here after you finish the exercise.
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let report_card = ReportCard {
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grade: 2.1,
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grade: "A+",
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student_name: "Gary Plotter".to_string(),
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student_age: 11,
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};
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@ -3,13 +3,11 @@
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// 'use' and 'as' keywords. Fix these 'use' statements to make the code compile.
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// Make me compile! Execute `rustlings hint modules2` for hints :)
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// I AM NOT DONE
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mod delicious_snacks {
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// TODO: Fix these use statements
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use self::fruits::PEAR as ???
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use self::veggies::CUCUMBER as ???
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pub use self::fruits::PEAR as fruit;
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pub use self::veggies::CUCUMBER as veggie;
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mod fruits {
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pub const PEAR: &'static str = "Pear";
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@ -5,10 +5,8 @@
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// from the std::time module. Bonus style points if you can do it with one line!
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// Make me compile! Execute `rustlings hint modules3` for hints :)
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// I AM NOT DONE
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// TODO: Complete this use statement
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use ???
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use std::time::{UNIX_EPOCH, SystemTime};
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fn main() {
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match SystemTime::now().duration_since(UNIX_EPOCH) {
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@ -7,8 +7,6 @@
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// you think each value is. That is, add either `string_slice` or `string`
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// before the parentheses on each line. If you're right, it will compile!
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// I AM NOT DONE
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fn string_slice(arg: &str) {
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println!("{}", arg);
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}
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@ -17,14 +15,14 @@ fn string(arg: String) {
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}
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fn main() {
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???("blue");
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???("red".to_string());
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???(String::from("hi"));
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???("rust is fun!".to_owned());
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???("nice weather".into());
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???(format!("Interpolation {}", "Station"));
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???(&String::from("abc")[0..1]);
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???(" hello there ".trim());
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???("Happy Monday!".to_string().replace("Mon", "Tues"));
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???("mY sHiFt KeY iS sTiCkY".to_lowercase());
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string_slice("blue");
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string("red".to_string());
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string(String::from("hi"));
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string("rust is fun!".to_owned());
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string("nice weather".into());
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string(format!("Interpolation {}", "Station"));
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string_slice(&String::from("abc")[0..1]);
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string_slice(" hello there ".trim());
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string("Happy Monday!".to_string().replace("Mon", "Tues"));
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string("mY sHiFt KeY iS sTiCkY".to_lowercase());
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}
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@ -2,13 +2,11 @@
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// Make me compile without changing the function signature!
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// Execute `rustlings hint strings1` for hints ;)
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// I AM NOT DONE
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fn main() {
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let answer = current_favorite_color();
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println!("My current favorite color is {}", answer);
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}
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fn current_favorite_color() -> String {
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"blue"
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String::from("blue")
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}
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@ -2,11 +2,9 @@
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// Make me compile without changing the function signature!
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// Execute `rustlings hint strings2` for hints :)
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// I AM NOT DONE
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fn main() {
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let word = String::from("green"); // Try not changing this line :)
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if is_a_color_word(word) {
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if is_a_color_word(&word) {
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println!("That is a color word I know!");
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} else {
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println!("That is not a color word I know.");
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