mattrob33 / grammateus Goto Github PK

Hello, @mattrob33!

I found your crate in the "New Crates" section in crates.io. I am interesting - what is your motivation to create this package? Are you a researcher in Greek history, or linguist, or something other?

I am also want to give you a tip how you can improve your code. As I can see a GreekChar is either have two or three bytes, but it isn't represented in its struct:

Therefore, it requires to match its length if it is not 2 or 3, although we know it can not be:

The approach to solve this problem is called "Make Illegal States Unrepresentable". In your case, we can make GreekChar not a byte array with its length, but enum with either two or three bytes, like this:

pub enum GreekChar {
    Two(u8, u8),
    Three(u8, u8, u8),
}

This will allow you to get rid of unreachable checks such as checking that length is not 2 or 3. For example, this is how is_lowercase_greek can be rewritten for new GreekChar enum (TODO is copied from source code):

pub fn is_lowercase_greek(char: &GreekChar) -> bool {
    match char {
        GreekChar::Two(0xCE, 0xB1..=0xBF) => true,
        GreekChar::Two(0xCF, 0x80..=0x89) => true,
        GreekChar::Two(_, _) => false,
        // TODO: implement is_lowercase for three-length char
        GreekChar::Three(_, _, _) => panic!("Not yet implented"),
    }
}

Now there is no need to check for length other than 2 or 3.