feruca 0.12.0

An implementation of the Unicode Collation Algorithm
Documentation 
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pub const fn pack_weights(variable: bool, primary: u16, secondary: u16, tertiary: u16) -> u32 {
    let upper = (primary as u32) << 16;

    let v_int = variable as u16;
    let lower = (v_int << 15) | (tertiary << 9) | secondary;

    upper | (lower as u32)
}

pub const fn primary(weights: u32) -> u16 {
    (weights >> 16) as u16
}

pub const fn secondary(weights: u32) -> u16 {
    ((weights & 0xFFFF) & 0b1_1111_1111) as u16
}

pub const fn shift_weights(weights: u32, last_variable: &mut bool) -> u32 {
    let variable = variability(weights);
    let primary = primary(weights);
    let tertiary = tertiary(weights);

    if variable {
        *last_variable = true;
        pack_weights(true, primary, 0, 0)
    } else if primary == 0 && (tertiary == 0 || *last_variable) {
        0
    } else {
        *last_variable = false;
        weights
    }
}

pub const fn tertiary(weights: u32) -> u16 {
    (((weights & 0xFFFF) >> 9) & 0b11_1111) as u16
}

pub const fn variability(weights: u32) -> bool {
    weights & (1 << 15) != 0
}