How do I parse a vector into a function? - rust

Question

The idea is to send a set of characters of a vector and let the function display the current correct guesses.
Here is my main:
fn main() {
let mut guessedLetters = vec![];
displayWord(guessedLetters);
}
And here is the function:
fn displayWord(correctGuess: Vec<char>) {
let mut currentWord = String::new();
for x in 0..5 {
currentWord.push(correctGuess[x]);
}
println!("Current guesses: {}", currentWord);
}
I don't know what I'm supposed to write inside the parameters of displayWord.

Answer 1

There's a couple of things wrong with your code.
The first error is pretty straight forward:
--> src/main.rs:38:25
|
38 | displayWord(guessed_Letters);
| ^^^^^^^^^^^^^^^ expected char, found enum `std::option::Option`
|
= note: expected type `std::vec::Vec<char>`
found type `std::vec::Vec<std::option::Option<char>>`
The function you wrote is expecting a vector a characters ... but you're passing it a vector of Option<char>. This is happening here:
guessed_Letters.push(line.chars().nth(0));
According to the documentation, the nth method returns an Option. The quick fix here is to unwrap the Option to get the underlying value:
guessed_Letters.push(line.chars().nth(0).unwrap());
Your next error is:
error[E0382]: use of moved value: `guessed_Letters`
--> src/main.rs:38:25
|
38 | displayWord(guessed_Letters);
| ^^^^^^^^^^^^^^^ value moved here in previous iteration of loop
|
= note: move occurs because `guessed_Letters` has type `std::vec::Vec<char>`, which does not implement the `Copy` trait
This is transferring ownership of the vector on the first iteration of the loop and the compiler is telling you that subsequent iterations would be in violation of Rust's ownership rules.
The solution here is to pass the vector by reference instead:
displayWord(&guessed_Letters);
..and your method should also accept a reference:
fn displayWord(correctGuess: &Vec<char>) {
let mut currentWord = String::new();
for x in 0..5 {
currentWord.push(correctGuess[x]);
}
println!("Current guesses: {}", currentWord);
}
This can be shortened to use a slice and still work:
fn displayWord(correctGuess: &[char]) {