mirror of
https://github.com/rust-lang/rustlings.git
synced 2024-05-26 05:46:07 +02:00
2cdd61294f
The `watch` command now requires user action to move to the next exercise. BREAKING CHANGE: this changes the behavior of `watch`.
149 lines
2.5 KiB
Rust
149 lines
2.5 KiB
Rust
// iterators3.rs
|
|
// This is a bigger exercise than most of the others! You can do it!
|
|
// Here is your mission, should you choose to accept it:
|
|
// 1. Complete the divide function to get the first four tests to pass
|
|
// 2. Uncomment the last two tests and get them to pass by filling in
|
|
// values for `x` using `division_results`.
|
|
// Scroll down for a minor hint for part 2, and scroll down further for
|
|
// a major hint.
|
|
// Have fun :-)
|
|
|
|
// I AM NOT DONE
|
|
|
|
#[derive(Debug, PartialEq, Eq)]
|
|
pub enum DivisionError {
|
|
NotDivisible(NotDivisibleError),
|
|
DivideByZero,
|
|
}
|
|
|
|
#[derive(Debug, PartialEq, Eq)]
|
|
pub struct NotDivisibleError {
|
|
dividend: i32,
|
|
divisor: i32,
|
|
}
|
|
|
|
// This function should calculate `a` divided by `b` if `a` is
|
|
// evenly divisible by b.
|
|
// Otherwise, it should return a suitable error.
|
|
pub fn divide(a: i32, b: i32) -> Result<i32, DivisionError> {}
|
|
|
|
#[cfg(test)]
|
|
mod tests {
|
|
use super::*;
|
|
|
|
// Tests that verify your `divide` function implementation
|
|
#[test]
|
|
fn test_success() {
|
|
assert_eq!(divide(81, 9), Ok(9));
|
|
}
|
|
|
|
#[test]
|
|
fn test_not_divisible() {
|
|
assert_eq!(
|
|
divide(81, 6),
|
|
Err(DivisionError::NotDivisible(NotDivisibleError {
|
|
dividend: 81,
|
|
divisor: 6
|
|
}))
|
|
);
|
|
}
|
|
|
|
#[test]
|
|
fn test_divide_by_0() {
|
|
assert_eq!(divide(81, 0), Err(DivisionError::DivideByZero));
|
|
}
|
|
|
|
#[test]
|
|
fn test_divide_0_by_something() {
|
|
assert_eq!(divide(0, 81), Ok(0));
|
|
}
|
|
|
|
// Iterator exercises using your `divide` function
|
|
/*
|
|
#[test]
|
|
fn result_with_list() {
|
|
let numbers = vec![27, 297, 38502, 81];
|
|
let division_results = numbers.into_iter().map(|n| divide(n, 27));
|
|
let x //... Fill in here!
|
|
assert_eq!(format!("{:?}", x), "Ok([1, 11, 1426, 3])");
|
|
}
|
|
|
|
#[test]
|
|
fn list_of_results() {
|
|
let numbers = vec![27, 297, 38502, 81];
|
|
let division_results = numbers.into_iter().map(|n| divide(n, 27));
|
|
let x //... Fill in here!
|
|
assert_eq!(format!("{:?}", x), "[Ok(1), Ok(11), Ok(1426), Ok(3)]");
|
|
}
|
|
*/
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
// Minor hint: In each of the two cases in the match in main, you can create x with either
|
|
// a 'turbofish' or by hinting the type of x to the compiler. You may try both.
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
// Major hint: Have a look at the Iter trait and at the explanation of its collect function.
|
|
// Especially the part about Result is interesting.
|