Auto merge of #186 - Jesse-Cameron:iterator-exercise2, r=komaeda
feat(iterators2): adds iterators2 exercise including config Hi there! I really enjoyed doing the rustlings exercises so I thought that I would try to add an exercise! This one just covers a couple of basic iterator operations. Getting people used to the `map` and `collect` functions. However, it does feel kinda similar to the next exercise. So I may also revisit some of the tests in iterators3 if we think that is necessary.
This commit is contained in:
commit
1570c328c6
145
exercises/standard_library_types/iterators2.rs
Normal file
145
exercises/standard_library_types/iterators2.rs
Normal file
@ -0,0 +1,145 @@
|
||||
// iterators2.rs
|
||||
// In this module, you'll learn some of unique advantages that iterators can offer
|
||||
// Step 1. Complete the `capitalize_first` function to pass the first two cases
|
||||
// Step 2. Apply the `capitalize_first` function to a vector of strings, ensuring that it
|
||||
// Step 3. Apply the `capitalize_first` function again to a list, but try and ensure it returns a single string
|
||||
// As always, there are hints below!
|
||||
|
||||
pub fn capitalize_first(input: &str) -> String {
|
||||
let mut c = input.chars();
|
||||
match c.next() {
|
||||
None => String::new(),
|
||||
Some(first) => first.collect()::<String>() + c.as_str(),
|
||||
}
|
||||
}
|
||||
|
||||
#[cfg(test)]
|
||||
mod tests {
|
||||
use super::*;
|
||||
|
||||
// Step 1.
|
||||
// Tests that verify your `capitalize_first` function implementation
|
||||
#[test]
|
||||
fn test_success() {
|
||||
assert_eq!(capitalize_first("hello"), "Hello");
|
||||
}
|
||||
|
||||
#[test]
|
||||
fn test_empty() {
|
||||
assert_eq!(capitalize_first(""), "");
|
||||
}
|
||||
|
||||
// Step 2.
|
||||
#[test]
|
||||
fn test_iterate_string_vec() {
|
||||
let words = vec!["hello", "world"];
|
||||
let capitalized_words: Vec<String> = // TODO
|
||||
assert_eq!(capitalized_words, ["Hello", "World"]);
|
||||
}
|
||||
|
||||
#[test]
|
||||
fn test_iterate_into_string() {
|
||||
let words = vec!["hello", " ", "world"];
|
||||
let capitalized_words = // TODO
|
||||
assert_eq!(capitalized_words, "Hello World");
|
||||
}
|
||||
}
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
// Step 1
|
||||
// You need to call something on `first` before it can be collected
|
||||
// Currently it's type is `char`. Have a look at the methods that are available on that type:
|
||||
// https://doc.rust-lang.org/std/primitive.char.html
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
// Step 2
|
||||
// First you'll need to turn the Vec into an iterator
|
||||
// Then you'll need to apply your function unto each item in the vector
|
||||
// P.s. Don't forget to collect() at the end!
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
// Step 3.
|
||||
// This is very similar to the previous test. The only real change is that you will need to
|
||||
// alter the type that collect is coerced into. For a bonus you could try doing this with a
|
||||
// turbofish
|
Reference in New Issue
Block a user