From 58fc67525bcd8fa5ebac0215992b39b866b24bd7 Mon Sep 17 00:00:00 2001
From: Yuhua Mai <yuhua@urbandoor.com>
Date: Sat, 16 May 2020 00:13:23 -0700
Subject: [PATCH] More exercises
---
.gitignore | 2 ++
exercises/clippy/clippy1.rs | 3 +--
exercises/clippy/clippy2.rs | 3 +--
exercises/error_handling/errors1.rs | 9 ++++-----
exercises/error_handling/errors2.rs | 3 +--
exercises/error_handling/errors3.rs | 5 +++--
exercises/error_handling/errorsn.rs | 11 +++++------
exercises/error_handling/option1.rs | 5 ++++-
exercises/error_handling/result1.rs | 9 +++++++--
exercises/option/option1.rs | 9 ++++-----
exercises/option/option2.rs | 5 ++---
11 files changed, 34 insertions(+), 30 deletions(-)
diff --git a/.gitignore b/.gitignore
index de87c1e..5eb4972 100644
--- a/.gitignore
+++ b/.gitignore
@@ -5,3 +5,5 @@ target/
*.pdb
exercises/clippy/Cargo.toml
exercises/clippy/Cargo.lock
+
+.idea
diff --git a/exercises/clippy/clippy1.rs b/exercises/clippy/clippy1.rs
index 2b4c635..862f71f 100644
--- a/exercises/clippy/clippy1.rs
+++ b/exercises/clippy/clippy1.rs
@@ -4,12 +4,11 @@
//
// 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() > 0.0001 {
println!("Success!");
}
}
diff --git a/exercises/clippy/clippy2.rs b/exercises/clippy/clippy2.rs
index 37af9ed..ec6af9e 100644
--- a/exercises/clippy/clippy2.rs
+++ b/exercises/clippy/clippy2.rs
@@ -1,12 +1,11 @@
// 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);
diff --git a/exercises/error_handling/errors1.rs b/exercises/error_handling/errors1.rs
index 9c24d85..b36c1ec 100644
--- a/exercises/error_handling/errors1.rs
+++ b/exercises/error_handling/errors1.rs
@@ -6,14 +6,13 @@
// 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 +27,7 @@ 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())
);
}
diff --git a/exercises/error_handling/errors2.rs b/exercises/error_handling/errors2.rs
index aad3a93..cfc8537 100644
--- a/exercises/error_handling/errors2.rs
+++ b/exercises/error_handling/errors2.rs
@@ -16,14 +16,13 @@
// 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)
}
diff --git a/exercises/error_handling/errors3.rs b/exercises/error_handling/errors3.rs
index 460ac5c..88d8f32 100644
--- a/exercises/error_handling/errors3.rs
+++ b/exercises/error_handling/errors3.rs
@@ -4,11 +4,10 @@
// 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";
@@ -20,6 +19,8 @@ fn main() {
tokens -= cost;
println!("You now have {} tokens.", tokens);
}
+
+ Ok(())
}
pub fn total_cost(item_quantity: &str) -> Result<i32, ParseIntError> {
diff --git a/exercises/error_handling/errorsn.rs b/exercises/error_handling/errorsn.rs
index 3079943..9c0e091 100644
--- a/exercises/error_handling/errorsn.rs
+++ b/exercises/error_handling/errorsn.rs
@@ -15,19 +15,18 @@
//
// Execute `rustlings hint errorsn` for hints :)
-// I AM NOT DONE
use std::error;
use std::fmt;
use std::io;
// PositiveNonzeroInteger is a struct defined below the tests.
-fn read_and_validate(b: &mut dyn io::BufRead) -> Result<PositiveNonzeroInteger, ???> {
+fn read_and_validate(b: &mut dyn io::BufRead) -> Result<PositiveNonzeroInteger, Box<dyn error::Error>> {
let mut line = String::new();
- b.read_line(&mut line);
- let num: i64 = line.trim().parse();
- let answer = PositiveNonzeroInteger::new(num);
- answer
+ b.read_line(&mut line)?;
+ let num: i64 = line.trim().parse()?;
+ let answer: PositiveNonzeroInteger = PositiveNonzeroInteger::new(num)?;
+ Ok(answer)
}
// This is a test helper function that turns a &str into a BufReader.
diff --git a/exercises/error_handling/option1.rs b/exercises/error_handling/option1.rs
index 5d81b15..00c6d6b 100644
--- a/exercises/error_handling/option1.rs
+++ b/exercises/error_handling/option1.rs
@@ -12,7 +12,10 @@ pub fn pop_too_much() -> bool {
let last = list.pop().unwrap();
println!("The last item in the list is {:?}", last);
- let second_to_last = list.pop().unwrap();
+ let second_to_last = match list.pop() {
+ Some(i) => i,
+ None => 0
+ };
println!(
"The second-to-last item in the list is {:?}",
second_to_last
diff --git a/exercises/error_handling/result1.rs b/exercises/error_handling/result1.rs
index b978001..25857cb 100644
--- a/exercises/error_handling/result1.rs
+++ b/exercises/error_handling/result1.rs
@@ -1,7 +1,6 @@
// result1.rs
// Make this test pass! Execute `rustlings hint result1` for hints :)
-// I AM NOT DONE
#[derive(PartialEq, Debug)]
struct PositiveNonzeroInteger(u64);
@@ -14,7 +13,13 @@ enum CreationError {
impl PositiveNonzeroInteger {
fn new(value: i64) -> Result<PositiveNonzeroInteger, CreationError> {
- Ok(PositiveNonzeroInteger(value as u64))
+ if value == 0 {
+ Err(CreationError::Zero)
+ } else if value < 0 {
+ Err(CreationError::Negative)
+ } else {
+ Ok(PositiveNonzeroInteger(value as u64))
+ }
}
}
diff --git a/exercises/option/option1.rs b/exercises/option/option1.rs
index 51c39f5..852911e 100644
--- a/exercises/option/option1.rs
+++ b/exercises/option/option1.rs
@@ -1,7 +1,6 @@
// 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>) {
@@ -9,15 +8,15 @@ fn print_number(maybe_number: Option<u16>) {
}
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] = [None; 5];
for iter in 0..5 {
let number_to_add: u16 = {
((iter * 5) + 2) / (4 * 16)
};
- numbers[iter] = number_to_add;
+ numbers[iter as usize] = Some(number_to_add);
}
}
diff --git a/exercises/option/option2.rs b/exercises/option/option2.rs
index a55f734..c77c80f 100644
--- a/exercises/option/option2.rs
+++ b/exercises/option/option2.rs
@@ -1,12 +1,11 @@
// option2.rs
// Make me compile! Execute `rustlings hint option2` for hints
-// I AM NOT DONE
fn main() {
let optional_value = Some(String::from("rustlings"));
// Make this an if let statement whose value is "Some" type
- value = optional_value {
+ if let Some(value) = optional_value {
println!("the value of optional value is: {}", value);
} else {
println!("The optional value doesn't contain anything!");
@@ -19,7 +18,7 @@ fn main() {
// 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
- value = optional_values_vec.pop() {
+ while let Some(Some(value)) = optional_values_vec.pop() {
println!("current value: {}", value);
}
}