part of the excerise

This commit is contained in:
Bruce 2023-03-27 15:01:36 +08:00
parent 7f1754ecc5
commit 4e37057ba9
23 changed files with 121 additions and 69 deletions

2
Cargo.lock generated
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@ -459,7 +459,7 @@ checksum = "f497285884f3fcff424ffc933e56d7cbca511def0c9831a7f9b5f6153e3cc89b"
[[package]] [[package]]
name = "rustlings" name = "rustlings"
version = "5.4.0" version = "5.4.1"
dependencies = [ dependencies = [
"argh", "argh",
"assert_cmd", "assert_cmd",

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@ -3,25 +3,23 @@
// and https://doc.rust-lang.org/std/convert/trait.AsMut.html, respectively. // and https://doc.rust-lang.org/std/convert/trait.AsMut.html, respectively.
// Execute `rustlings hint as_ref_mut` or use the `hint` watch subcommand for a hint. // Execute `rustlings hint as_ref_mut` or use the `hint` watch subcommand for a hint.
// I AM NOT DONE
// Obtain the number of bytes (not characters) in the given argument. // Obtain the number of bytes (not characters) in the given argument.
// TODO: Add the AsRef trait appropriately as a trait bound. // TODO: 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() arg.as_ref().as_bytes().len()
} }
// Obtain the number of characters (not bytes) in the given argument. // Obtain the number of characters (not bytes) in the given argument.
// TODO: Add the AsRef trait appropriately as a trait bound. // TODO: 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() arg.as_ref().chars().count()
} }
// Squares a number using as_mut(). // Squares a number using as_mut().
// TODO: Add the appropriate trait bound. // TODO: Add the appropriate trait bound.
fn num_sq<T>(arg: &mut T) { fn num_sq<T: AsMut<u32>>(arg: &mut T) {
// TODO: Implement the function body. // TODO: Implement the function body.
??? *arg.as_mut() *= 3;
} }
#[cfg(test)] #[cfg(test)]

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@ -35,10 +35,23 @@ impl Default for Person {
// If while parsing the age, something goes wrong, then return the default of 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 // Otherwise, then return an instantiated Person object with the results
// I AM NOT DONE
impl From<&str> for Person { impl From<&str> for Person {
fn from(s: &str) -> Person { fn from(s: &str) -> Person {
let p: Vec<_> = s.split(',').collect();
if p.len() != 2 || p[0].len() == 0 {
return Person::default();
}
let age = p[1].parse::<usize>();
if let Err(e) = age {
return Person::default();
}
Person {
name: p[0].to_string(),
age: age.unwrap()
}
} }
} }

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@ -28,8 +28,6 @@ enum ParsePersonError {
ParseInt(ParseIntError), ParseInt(ParseIntError),
} }
// I AM NOT DONE
// Steps: // Steps:
// 1. If the length of the provided string is 0, an error should be returned // 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 // 2. Split the given string on the commas present in it
@ -46,6 +44,25 @@ enum ParsePersonError {
impl FromStr for Person { impl FromStr for Person {
type Err = ParsePersonError; type Err = ParsePersonError;
fn from_str(s: &str) -> Result<Person, Self::Err> { fn from_str(s: &str) -> Result<Person, Self::Err> {
if s == "" {
return Err(ParsePersonError::Empty);
}
let p: Vec<_> = s.split(',').collect();
if p.len() != 2 {
return Err(ParsePersonError::BadLen);
}
if p[0].len() == 0 {
return Err(ParsePersonError::NoName);
}
let age = p[1].parse::<usize>();
if let Err(e) = age {
return Err(ParsePersonError::ParseInt(e))
}
Ok(Person {
name: p[0].to_string(),
age: age.unwrap()
})
} }
} }

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@ -23,8 +23,6 @@ enum IntoColorError {
IntConversion, IntConversion,
} }
// I AM NOT DONE
// Your task is to complete this implementation // Your task is to complete this implementation
// and return an Ok result of inner type Color. // and return an Ok result of inner type Color.
// You need to create an implementation for a tuple of three integers, // You need to create an implementation for a tuple of three integers,
@ -34,17 +32,43 @@ enum IntoColorError {
// but the slice implementation needs to check the slice length! // but the slice implementation needs to check the slice length!
// Also note that correct RGB color values must be integers in the 0..=255 range. // Also note that correct RGB color values must be integers in the 0..=255 range.
fn check(c: i16) -> bool {
if c < 256 && c > -1 {
return true;
}
false
}
fn color_build(red: i16, green: i16, blue: i16) -> Option<Color> {
if check(red) && check(green) && check(blue) {
return Some(Color {
red: red as u8,
green: green as u8,
blue: blue as u8,
});
}
None
}
// Tuple implementation // Tuple implementation
impl TryFrom<(i16, i16, i16)> for Color { impl TryFrom<(i16, i16, i16)> for Color {
type Error = IntoColorError; type Error = IntoColorError;
fn try_from(tuple: (i16, i16, i16)) -> Result<Self, Self::Error> { fn try_from((red, green, blue): (i16, i16, i16)) -> Result<Self, Self::Error> {
if let Some(color) = color_build(red, green, blue) {
return Ok(color);
}
Err(IntoColorError::IntConversion)
} }
} }
// Array implementation // Array implementation
impl TryFrom<[i16; 3]> for Color { impl TryFrom<[i16; 3]> for Color {
type Error = IntoColorError; type Error = IntoColorError;
fn try_from(arr: [i16; 3]) -> Result<Self, Self::Error> { fn try_from([red, green, blue]: [i16; 3]) -> Result<Self, Self::Error> {
if let Some(color) = color_build(red, green, blue) {
return Ok(color);
}
Err(IntoColorError::IntConversion)
} }
} }
@ -52,6 +76,14 @@ impl TryFrom<[i16; 3]> for Color {
impl TryFrom<&[i16]> for Color { impl TryFrom<&[i16]> for Color {
type Error = IntoColorError; type Error = IntoColorError;
fn try_from(slice: &[i16]) -> Result<Self, Self::Error> { fn try_from(slice: &[i16]) -> Result<Self, Self::Error> {
if slice.len() != 3 {
return Err(IntoColorError::BadLen);
}
let [red, green, blue]: [i16; 3] = slice.try_into().unwrap();
if let Some(color) = color_build(red, green, blue) {
return Ok(color);
}
Err(IntoColorError::IntConversion)
} }
} }

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@ -6,11 +6,10 @@
// and returns the proper type. // and returns the proper type.
// Execute `rustlings hint using_as` or use the `hint` watch subcommand for a hint. // Execute `rustlings hint using_as` or use the `hint` watch subcommand for a hint.
// I AM NOT DONE
fn average(values: &[f64]) -> f64 { fn average(values: &[f64]) -> f64 {
let total = values.iter().sum::<f64>(); let total = values.iter().sum::<f64>();
total / values.len() total / values.len() as f64
} }
fn main() { fn main() {

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@ -7,9 +7,7 @@
// //
// Execute `rustlings hint lifetimes1` or use the `hint` watch subcommand for a hint. // Execute `rustlings hint lifetimes1` or use the `hint` watch subcommand for a hint.
// I AM NOT DONE fn longest<'a>(x: &'a str, y: &'a str) -> &'a str {
fn longest(x: &str, y: &str) -> &str {
if x.len() > y.len() { if x.len() > y.len() {
x x
} else { } else {

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@ -6,8 +6,6 @@
// //
// Execute `rustlings hint lifetimes2` or use the `hint` watch subcommand for a hint. // Execute `rustlings hint lifetimes2` or use the `hint` watch subcommand for a hint.
// I AM NOT DONE
fn longest<'a>(x: &'a str, y: &'a str) -> &'a str { fn longest<'a>(x: &'a str, y: &'a str) -> &'a str {
if x.len() > y.len() { if x.len() > y.len() {
x x
@ -22,6 +20,6 @@ fn main() {
{ {
let string2 = String::from("xyz"); let string2 = String::from("xyz");
result = longest(string1.as_str(), string2.as_str()); result = longest(string1.as_str(), string2.as_str());
println!("The longest string is '{}'", result);
} }
println!("The longest string is '{}'", result);
} }

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@ -4,11 +4,10 @@
// //
// Execute `rustlings hint lifetimes3` or use the `hint` watch subcommand for a hint. // Execute `rustlings hint lifetimes3` or use the `hint` watch subcommand for a hint.
// I AM NOT DONE
struct Book { struct Book<'a> {
author: &str, author: &'a str,
title: &str, title: &'a str,
} }
fn main() { fn main() {

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@ -2,8 +2,6 @@
// Fill in the rest of the line that has code missing! // Fill in the rest of the line that has code missing!
// No hints, there's no tricks, just get used to typing these :) // No hints, there's no tricks, just get used to typing these :)
// I AM NOT DONE
fn main() { fn main() {
// Booleans (`bool`) // Booleans (`bool`)
@ -12,7 +10,7 @@ fn main() {
println!("Good morning!"); println!("Good morning!");
} }
let // Finish the rest of this line like the example! Or make it be false! let is_evening = false; // Finish the rest of this line like the example! Or make it be false!
if is_evening { if is_evening {
println!("Good evening!"); println!("Good evening!");
} }

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@ -2,8 +2,6 @@
// Fill in the rest of the line that has code missing! // Fill in the rest of the line that has code missing!
// No hints, there's no tricks, just get used to typing these :) // No hints, there's no tricks, just get used to typing these :)
// I AM NOT DONE
fn main() { fn main() {
// Characters (`char`) // Characters (`char`)
@ -18,7 +16,8 @@ fn main() {
println!("Neither alphabetic nor numeric!"); println!("Neither alphabetic nor numeric!");
} }
let // Finish this line like the example! What's your favorite character? let your_character = '$';
// Finish this line like the example! What's your favorite character?
// Try a letter, try a number, try a special character, try a character // Try a letter, try a number, try a special character, try a character
// from a different language than your own, try an emoji! // from a different language than your own, try an emoji!
if your_character.is_alphabetic() { if your_character.is_alphabetic() {

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@ -2,10 +2,8 @@
// Create an array with at least 100 elements in it where the ??? is. // Create an array with at least 100 elements in it where the ??? is.
// Execute `rustlings hint primitive_types3` or use the `hint` watch subcommand for a hint. // Execute `rustlings hint primitive_types3` or use the `hint` watch subcommand for a hint.
// I AM NOT DONE
fn main() { fn main() {
let a = ??? let a = [101;0];
if a.len() >= 100 { if a.len() >= 100 {
println!("Wow, that's a big array!"); println!("Wow, that's a big array!");

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

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@ -2,11 +2,9 @@
// Destructure the `cat` tuple so that the println will work. // Destructure the `cat` tuple so that the println will work.
// Execute `rustlings hint primitive_types5` or use the `hint` watch subcommand for a hint. // Execute `rustlings hint primitive_types5` or use the `hint` watch subcommand for a hint.
// I AM NOT DONE
fn main() { fn main() {
let cat = ("Furry McFurson", 3.5); let cat = ("Furry McFurson", 3.5);
let /* your pattern here */ = cat; let (name, age) = cat;
println!("{} is {} years old.", name, age); println!("{} is {} years old.", name, age);
} }

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@ -3,13 +3,11 @@
// You can put the expression for the second element where ??? is so that the test passes. // You can put the expression for the second element where ??? is so that the test passes.
// Execute `rustlings hint primitive_types6` or use the `hint` watch subcommand for a hint. // Execute `rustlings hint primitive_types6` or use the `hint` watch subcommand for a hint.
// I AM NOT DONE
#[test] #[test]
fn indexing_tuple() { fn indexing_tuple() {
let numbers = (1, 2, 3); let numbers = (1, 2, 3);
// Replace below ??? with the tuple indexing syntax. // Replace below ??? with the tuple indexing syntax.
let second = ???; let second = numbers.1;
assert_eq!(2, second, assert_eq!(2, second,
"This is not the 2nd number in the tuple!") "This is not the 2nd number in the tuple!")

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@ -10,10 +10,13 @@
// Write a function that calculates the price of an order of apples given // Write a function that calculates the price of an order of apples given
// the quantity bought. No hints this time! // the quantity bought. No hints this time!
// I AM NOT DONE
// Put your function here! // Put your function here!
// fn calculate_price_of_apples { fn calculate_price_of_apples(num: u32) -> u32 {
match num {
n if n <= 40 => num * 2,
others => num
}
}
// Don't modify this function! // Don't modify this function!
#[test] #[test]

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@ -18,8 +18,6 @@
// - The output element is going to be a Vector of strings. // - The output element is going to be a Vector of strings.
// No hints this time! // No hints this time!
// I AM NOT DONE
pub enum Command { pub enum Command {
Uppercase, Uppercase,
Trim, Trim,
@ -30,11 +28,16 @@ mod my_module {
use super::Command; use super::Command;
// TODO: Complete the function signature! // TODO: Complete the function signature!
pub fn transformer(input: ???) -> ??? { pub fn transformer(input: Vec<(String, Command)>) -> Vec<String> {
// TODO: Complete the output declaration! // TODO: Complete the output declaration!
let mut output: ??? = vec![]; let mut output: Vec<String> = vec![];
for (string, command) in input.iter() { for (string, command) in input.iter() {
// TODO: Complete the function body. You can do it! // TODO: Complete the function body. You can do it!
match command {
Command::Uppercase => output.push(string.to_uppercase()),
Command::Trim => output.push(string.trim().to_string()),
Command::Append(n) => output.push(string.to_owned() + &"bar".repeat(*n))
}
} }
output output
} }
@ -43,7 +46,7 @@ mod my_module {
#[cfg(test)] #[cfg(test)]
mod tests { mod tests {
// TODO: What do we need to import to have `transformer` in scope? // TODO: What do we need to import to have `transformer` in scope?
use ???; use crate::my_module::transformer;
use super::Command; use super::Command;
#[test] #[test]

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@ -14,15 +14,15 @@
// Execute `rustlings hint quiz3` or use the `hint` watch subcommand for a hint. // Execute `rustlings hint quiz3` or use the `hint` watch subcommand for a hint.
// I AM NOT DONE pub struct ReportCard<T> {
pub grade: T,
pub struct ReportCard {
pub grade: f32,
pub student_name: String, pub student_name: String,
pub student_age: u8, pub student_age: u8,
} }
impl ReportCard { impl <T> ReportCard<T>
where T: std::fmt::Display
{
pub fn print(&self) -> String { pub fn print(&self) -> String {
format!("{} ({}) - achieved a grade of {}", format!("{} ({}) - achieved a grade of {}",
&self.student_name, &self.student_age, &self.grade) &self.student_name, &self.student_age, &self.grade)
@ -50,7 +50,7 @@ mod tests {
fn generate_alphabetic_report_card() { fn generate_alphabetic_report_card() {
// TODO: Make sure to change the grade here after you finish the exercise. // TODO: Make sure to change the grade here after you finish the exercise.
let report_card = ReportCard { let report_card = ReportCard {
grade: 2.1, grade: "A+",
student_name: "Gary Plotter".to_string(), student_name: "Gary Plotter".to_string(),
student_age: 11, student_age: 11,
}; };

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@ -9,14 +9,15 @@
// implementing this trait. // implementing this trait.
// Execute `rustlings hint traits1` or use the `hint` watch subcommand for a hint. // Execute `rustlings hint traits1` or use the `hint` watch subcommand for a hint.
// I AM NOT DONE
trait AppendBar { trait AppendBar {
fn append_bar(self) -> Self; fn append_bar(self) -> Self;
} }
impl AppendBar for String { impl AppendBar for String {
// TODO: Implement `AppendBar` for type `String`. // TODO: Implement `AppendBar` for type `String`.
fn append_bar(self) -> Self {
self + "Bar"
}
} }
fn main() { fn main() {

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@ -11,13 +11,17 @@
// you can do this! // you can do this!
// Execute `rustlings hint traits2` or use the `hint` watch subcommand for a hint. // Execute `rustlings hint traits2` or use the `hint` watch subcommand for a hint.
// I AM NOT DONE
trait AppendBar { trait AppendBar {
fn append_bar(self) -> Self; fn append_bar(self) -> Self;
} }
// TODO: Implement trait `AppendBar` for a vector of strings. // TODO: Implement trait `AppendBar` for a vector of strings.
impl AppendBar for Vec<String> {
fn append_bar(mut self) -> Self {
self.push("Bar".to_owned());
self
}
}
#[cfg(test)] #[cfg(test)]
mod tests { mod tests {

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@ -7,10 +7,11 @@
// Consider what you can add to the Licensed trait. // Consider what you can add to the Licensed trait.
// Execute `rustlings hint traits3` or use the `hint` watch subcommand for a hint. // Execute `rustlings hint traits3` or use the `hint` watch subcommand for a hint.
// I AM NOT DONE
pub trait Licensed { pub trait Licensed {
fn licensing_info(&self) -> String; fn licensing_info(&self) -> String {
"Some information".into()
}
} }
struct SomeSoftware { struct SomeSoftware {

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@ -4,8 +4,6 @@
// Don't change any line other than the marked one. // Don't change any line other than the marked one.
// Execute `rustlings hint traits4` or use the `hint` watch subcommand for a hint. // Execute `rustlings hint traits4` or use the `hint` watch subcommand for a hint.
// I AM NOT DONE
pub trait Licensed { pub trait Licensed {
fn licensing_info(&self) -> String { fn licensing_info(&self) -> String {
"some information".to_string() "some information".to_string()
@ -20,7 +18,7 @@ impl Licensed for SomeSoftware {}
impl Licensed for OtherSoftware {} impl Licensed for OtherSoftware {}
// YOU MAY ONLY CHANGE THE NEXT LINE // YOU MAY ONLY CHANGE THE NEXT LINE
fn compare_license_types(software: ??, software_two: ??) -> bool { fn compare_license_types(software: impl Licensed, software_two: impl Licensed) -> bool {
software.licensing_info() == software_two.licensing_info() software.licensing_info() == software_two.licensing_info()
} }

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@ -4,8 +4,6 @@
// Don't change any line other than the marked one. // Don't change any line other than the marked one.
// Execute `rustlings hint traits5` or use the `hint` watch subcommand for a hint. // Execute `rustlings hint traits5` or use the `hint` watch subcommand for a hint.
// I AM NOT DONE
pub trait SomeTrait { pub trait SomeTrait {
fn some_function(&self) -> bool { fn some_function(&self) -> bool {
true true
@ -27,7 +25,7 @@ impl SomeTrait for OtherStruct {}
impl OtherTrait for OtherStruct {} impl OtherTrait for OtherStruct {}
// YOU MAY ONLY CHANGE THE NEXT LINE // YOU MAY ONLY CHANGE THE NEXT LINE
fn some_func(item: ??) -> bool { fn some_func(item: impl SomeTrait + OtherTrait) -> bool {
item.some_function() && item.other_function() item.some_function() && item.other_function()
} }