//! Per-residue secondary-structure vocabulary shared by readers and analyses.
/// A residue-level structural assignment.
#[derive(Clone, Copy, Debug, Default, PartialEq, Eq)]
pub enum SecondaryStructure {
/// The file and available analyses supplied no assignment.
#[default]
Unknown,
/// A residue outside a helix or sheet.
Coil,
/// An alpha or other helical segment.
Helix,
/// A beta strand.
Strand,
/// A short hydrogen-bonded turn.
Turn,
}