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pub mod gv;

use crate::number::Number;

#[derive(Clone, Debug, Default, Hash)]
pub struct CirculantMatrix<T = f64>
where
    T: Number,
{
    col_elems: Vec<T>,
}

impl<T> CirculantMatrix<T>
where
    T: Number,
{
    pub fn new(col_elems: Vec<T>) -> Self {
        Self { col_elems }
    }

    pub fn from(row_elems: &[T]) -> Self {
        let col_elems = if row_elems.len() <= 1 {
            row_elems.to_vec()
        } else {
            row_elems[0..1]
                .iter()
                .chain(row_elems[1..].iter().rev())
                .map(|&e| e)
                .collect::<Vec<_>>()
        };

        Self::new(col_elems)
    }

    pub fn col_elems(&self) -> &[T] {
        &self.col_elems
    }

    pub fn row_elems(&self) -> Vec<T> {
        if self.col_elems.len() <= 1 {
            return self.col_elems.clone();
        }

        self.col_elems[0..1]
            .iter()
            .chain(self.col_elems[1..].iter().rev())
            .map(|&e| e)
            .collect::<Vec<_>>()
    }
}