done till exercises/threads/threads1

This commit is contained in:
ben1009 2023-02-17 00:27:55 +08:00
parent 6623e38988
commit b84ba2b903
14 changed files with 60 additions and 55 deletions

View File

@ -1,6 +1,6 @@
# Error handling # Error handling
Most errors arent serious enough to require the program to stop entirely. Most errors arent serious enough to require the program to stop entirely.
Sometimes, when a function fails, its for a reason that you can easily interpret and respond to. Sometimes, when a function fails, its for a reason that you can easily interpret and respond to.
For example, if you try to open a file and that operation fails because the file doesnt exist, you might want to create the file instead of terminating the process. For example, if you try to open a file and that operation fails because the file doesnt exist, you might want to create the file instead of terminating the process.

View File

@ -8,17 +8,15 @@
// //
// Execute `rustlings hint iterators1` or use the `hint` watch subcommand for a hint. // Execute `rustlings hint iterators1` or use the `hint` watch subcommand for a hint.
// I AM NOT DONE fn main() {
fn main () {
let my_fav_fruits = vec!["banana", "custard apple", "avocado", "peach", "raspberry"]; 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(), 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(), Some(&"avocado"));
assert_eq!(my_iterable_fav_fruits.next(), ???); // TODO: Step 3 assert_eq!(my_iterable_fav_fruits.next(), Some(&"peach")); // TODO: Step 3
assert_eq!(my_iterable_fav_fruits.next(), Some(&"raspberry")); assert_eq!(my_iterable_fav_fruits.next(), Some(&"raspberry"));
assert_eq!(my_iterable_fav_fruits.next(), ???); // TODO: Step 4 assert_eq!(my_iterable_fav_fruits.next(), None); // TODO: Step 4
} }

View File

@ -3,8 +3,6 @@
// can offer. Follow the steps to complete the exercise. // can offer. Follow the steps to complete the exercise.
// Execute `rustlings hint iterators2` or use the `hint` watch subcommand for a hint. // Execute `rustlings hint iterators2` or use the `hint` watch subcommand for a hint.
// I AM NOT DONE
// Step 1. // Step 1.
// Complete the `capitalize_first` function. // Complete the `capitalize_first` function.
// "hello" -> "Hello" // "hello" -> "Hello"
@ -12,7 +10,7 @@ pub fn capitalize_first(input: &str) -> String {
let mut c = input.chars(); let mut c = input.chars();
match c.next() { match c.next() {
None => String::new(), None => String::new(),
Some(first) => ???, Some(first) => first.to_uppercase().to_string() + c.as_str(),
} }
} }
@ -21,7 +19,7 @@ pub fn capitalize_first(input: &str) -> String {
// Return a vector of strings. // Return a vector of strings.
// ["hello", "world"] -> ["Hello", "World"] // ["hello", "world"] -> ["Hello", "World"]
pub fn capitalize_words_vector(words: &[&str]) -> Vec<String> { pub fn capitalize_words_vector(words: &[&str]) -> Vec<String> {
vec![] words.iter().map(|w| capitalize_first(w)).collect()
} }
// Step 3. // Step 3.
@ -29,7 +27,7 @@ pub fn capitalize_words_vector(words: &[&str]) -> Vec<String> {
// Return a single string. // Return a single string.
// ["hello", " ", "world"] -> "Hello World" // ["hello", " ", "world"] -> "Hello World"
pub fn capitalize_words_string(words: &[&str]) -> String { pub fn capitalize_words_string(words: &[&str]) -> String {
String::new() words.iter().map(|w| capitalize_first(w)).collect()
} }
#[cfg(test)] #[cfg(test)]

View File

@ -6,7 +6,7 @@
// list_of_results functions. // list_of_results functions.
// Execute `rustlings hint iterators3` or use the `hint` watch subcommand for a hint. // Execute `rustlings hint iterators3` or use the `hint` watch subcommand for a hint.
// I AM NOT DONE use std::error::Error;
#[derive(Debug, PartialEq, Eq)] #[derive(Debug, PartialEq, Eq)]
pub enum DivisionError { pub enum DivisionError {
@ -23,21 +23,38 @@ pub struct NotDivisibleError {
// Calculate `a` divided by `b` if `a` is evenly divisible by `b`. // Calculate `a` divided by `b` if `a` is evenly divisible by `b`.
// Otherwise, return a suitable error. // 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> {
todo!(); if b == 0 {
return Err(DivisionError::DivideByZero);
}
if a % b == 0 {
return Ok(a / b);
}
Err(DivisionError::NotDivisible(NotDivisibleError {
dividend: a,
divisor: b,
}))
} }
// Complete the function and return a value of the correct type so the test passes. // Complete the function and return a value of the correct type so the test passes.
// Desired output: Ok([1, 11, 1426, 3]) // 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 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));
// https://doc.rust-lang.org/std/result/enum.Result.html#impl-FromIterator%3CResult%3CA%2C%20E%3E%3E-for-Result%3CV%2C%20E%3E
division_results.collect()
} }
// Complete the function and return a value of the correct type so the test passes. // 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)] // 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 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));
// https://doc.rust-lang.org/std/vec/struct.Vec.html#impl-FromIterator%3CT%3E-for-Vec%3CT%2C%20Global%3E
division_results.collect()
// let mut v = vec![];
// division_results.for_each(|n| v.push(n));
// v
} }
#[cfg(test)] #[cfg(test)]

View File

@ -1,8 +1,6 @@
// iterators4.rs // iterators4.rs
// Execute `rustlings hint iterators4` or use the `hint` watch subcommand for a hint. // Execute `rustlings hint iterators4` or use the `hint` watch subcommand for a hint.
// I AM NOT DONE
pub fn factorial(num: u64) -> u64 { pub fn factorial(num: u64) -> u64 {
// Complete this function to return the factorial of num // Complete this function to return the factorial of num
// Do not use: // Do not use:
@ -13,6 +11,9 @@ pub fn factorial(num: u64) -> u64 {
// For an extra challenge, don't use: // For an extra challenge, don't use:
// - recursion // - recursion
// Execute `rustlings hint iterators4` for hints. // Execute `rustlings hint iterators4` for hints.
(1..=num).fold(1, |ret, n| ret * n)
// (1..=num).product()
} }
#[cfg(test)] #[cfg(test)]

View File

@ -10,8 +10,6 @@
// //
// Make the code compile and the tests pass. // Make the code compile and the tests pass.
// I AM NOT DONE
use std::collections::HashMap; use std::collections::HashMap;
#[derive(Clone, Copy, PartialEq, Eq)] #[derive(Clone, Copy, PartialEq, Eq)]
@ -34,7 +32,7 @@ fn count_for(map: &HashMap<String, Progress>, value: Progress) -> usize {
fn count_iterator(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 is a hashmap with String keys and Progress values.
// map = { "variables1": Complete, "from_str": None, ... } // map = { "variables1": Complete, "from_str": None, ... }
todo!(); map.values().filter(|v| *v == &value).count()
} }
fn count_collection_for(collection: &[HashMap<String, Progress>], value: Progress) -> usize { fn count_collection_for(collection: &[HashMap<String, Progress>], value: Progress) -> usize {
@ -53,7 +51,7 @@ fn count_collection_iterator(collection: &[HashMap<String, Progress>], value: Pr
// collection is a slice of hashmaps. // collection is a slice of hashmaps.
// collection = [{ "variables1": Complete, "from_str": None, ... }, // collection = [{ "variables1": Complete, "from_str": None, ... },
// { "variables2": Complete, ... }, ... ] // { "variables2": Complete, ... }, ... ]
todo!(); collection.iter().map(|v| count_iterator(v, value)).sum()
} }
#[cfg(test)] #[cfg(test)]

View File

@ -3,12 +3,12 @@
Lifetimes tell the compiler how to check whether references live long Lifetimes tell the compiler how to check whether references live long
enough to be valid in any given situation. For example lifetimes say enough to be valid in any given situation. For example lifetimes say
"make sure parameter 'a' lives as long as parameter 'b' so that the return "make sure parameter 'a' lives as long as parameter 'b' so that the return
value is valid". value is valid".
They are only necessary on borrows, i.e. references, They are only necessary on borrows, i.e. references,
since copied parameters or moves are owned in their scope and cannot since copied parameters or moves are owned in their scope and cannot
be referenced outside. Lifetimes mean that calling code of e.g. functions be referenced outside. Lifetimes mean that calling code of e.g. functions
can be checked to make sure their arguments are valid. Lifetimes are can be checked to make sure their arguments are valid. Lifetimes are
restrictive of their callers. restrictive of their callers.
## Further information ## Further information

View File

@ -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 {

View File

@ -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);
} }

View File

@ -4,17 +4,18 @@
// //
// 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<'a> {
author: &'a str,
struct Book { title: &'a str,
author: &str,
title: &str,
} }
fn main() { fn main() {
let name = String::from("Jill Smith"); let name = String::from("Jill Smith");
let title = String::from("Fish Flying"); let title = String::from("Fish Flying");
let book = Book { author: &name, title: &title }; let book = Book {
author: &name,
title: &title,
};
println!("{} by {}", book.title, book.author); println!("{} by {}", book.title, book.author);
} }

View File

@ -14,18 +14,20 @@
// 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 use std::fmt::Display;
pub struct ReportCard { pub struct ReportCard<T> {
pub grade: f32, pub grade: T,
pub student_name: String, pub student_name: String,
pub student_age: u8, pub student_age: u8,
} }
impl ReportCard { impl<T: Display> ReportCard<T> {
pub fn print(&self) -> String { pub fn print(&self) -> String {
format!("{} ({}) - achieved a grade of {}", format!(
&self.student_name, &self.student_age, &self.grade) "{} ({}) - achieved a grade of {}",
&self.student_name, &self.student_age, &self.grade
)
} }
} }
@ -50,7 +52,7 @@ 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+".to_string(),
student_name: "Gary Plotter".to_string(), student_name: "Gary Plotter".to_string(),
student_age: 11, student_age: 11,
}; };

View File

@ -7,12 +7,10 @@
// pass! Make the test fail! // pass! Make the test fail!
// Execute `rustlings hint tests1` or use the `hint` watch subcommand for a hint. // Execute `rustlings hint tests1` or use the `hint` watch subcommand for a hint.
// I AM NOT DONE
#[cfg(test)] #[cfg(test)]
mod tests { mod tests {
#[test] #[test]
fn you_can_assert() { fn you_can_assert() {
assert!(); assert!(true);
} }
} }

View File

@ -3,12 +3,10 @@
// pass! Make the test fail! // pass! Make the test fail!
// Execute `rustlings hint tests2` or use the `hint` watch subcommand for a hint. // Execute `rustlings hint tests2` or use the `hint` watch subcommand for a hint.
// I AM NOT DONE
#[cfg(test)] #[cfg(test)]
mod tests { mod tests {
#[test] #[test]
fn you_can_assert_eq() { fn you_can_assert_eq() {
assert_eq!(); assert_eq!(1, 1);
} }
} }

View File

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