#[derive(Debug, PartialEq)]
pub struct Dna(String);

#[derive(Debug, PartialEq)]
pub struct Rna(String);

impl Dna {
    pub fn new(dna: &str) -> Result<Dna, usize> {
        dna.chars()
            .enumerate()
            .find(|(_, n)| !"ACGT".contains(*n))
            .map_or_else(|| Ok(Dna(dna.to_string())), |(i, _)| Err(i))
    }

    pub fn into_rna(self) -> Rna {
        Rna(self
            .0
            .as_str()
            .chars()
            .map(|n| match n {
                'A' => 'U',
                'C' => 'G',
                'G' => 'C',
                'T' => 'A',
                a => a,
            })
            .collect())
    }
}

impl Rna {
    pub fn new(rna: &str) -> Result<Rna, usize> {
        rna.chars()
            .enumerate()
            .find(|(_, n)| !"ACGU".contains(*n))
            .map_or_else(|| Ok(Rna(rna.to_string())), |(i, _)| Err(i))
    }
}