fix(iterators2): Moved errors out of tests.

Closes #359
This commit is contained in:
apogeeoak 2021-02-11 21:24:32 -05:00
parent ab57c26cf9
commit baf4ba175b
2 changed files with 33 additions and 24 deletions

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@ -1,28 +1,41 @@
// iterators2.rs
// In this module, you'll learn some of the 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.
// Ensure that it returns a vector of strings as well.
// Step 3. Apply the `capitalize_first` function again to a list.
// Try to ensure it returns a single string.
// In this exercise, you'll learn some of the unique advantages that iterators
// can offer. Follow the steps to complete the exercise.
// As always, there are hints if you execute `rustlings hint iterators2`!
// I AM NOT DONE
// Step 1.
// Complete the `capitalize_first` function.
// "hello" -> "Hello"
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(),
Some(first) => ???,
}
}
// Step 2.
// Apply the `capitalize_first` function to a slice of string slices.
// Return a vector of strings.
// ["hello", "world"] -> ["Hello", "World"]
pub fn capitalize_words_vector(words: &[&str]) -> Vec<String> {
vec![]
}
// Step 3.
// Apply the `capitalize_first` function again to a slice of string slices.
// Return a single string.
// ["hello", " ", "world"] -> "Hello World"
pub fn capitalize_words_string(words: &[&str]) -> String {
String::new()
}
#[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");
@ -33,18 +46,15 @@ mod tests {
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"]);
assert_eq!(capitalize_words_vector(&words), ["Hello", "World"]);
}
#[test]
fn test_iterate_into_string() {
let words = vec!["hello", " ", "world"];
let capitalized_words = // TODO
assert_eq!(capitalized_words, "Hello World");
assert_eq!(capitalize_words_string(&words), "Hello World");
}
}

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@ -704,21 +704,20 @@ path = "exercises/standard_library_types/iterators2.rs"
mode = "test"
hint = """
Step 1
You need to call something on `first` before it can be collected
Currently its type is `char`. Have a look at the methods that are available on that type:
The variable `first` is a `char`. It needs to be capitalized and added to the
remaining characters in `c` in order to return the correct `String`.
The remaining characters in `c` can be viewed as a string slice using the
`as_str` method.
The documentation for `char` contains many useful methods.
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!
Create an iterator from the slice. Transform the iterated values by applying
the `capitalize_first` function. Remember to collect the iterator.
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"""
This is surprising similar to the previous solution. Collect is very powerful
and very general. Rust just needs to know the desired type."""
[[exercises]]
name = "iterators3"