Enum Key 

pub enum Key<'a> {
    Name(&'a str),
    Nth(&'a str, usize),
}

Addresses a keyword either by name (strict: it must be unique) or by a specific occurrence when a name repeats.

You rarely name Key directly — every keyword accessor takes impl Into<Key>, so both forms work:

use xisf_header::Header;
let mut h = Header::new();
h.append("HISTORY", "first").unwrap();
h.append("HISTORY", "second").unwrap();

// Bare name is ambiguous here → error; select an occurrence instead.
assert!(h.get_str("HISTORY").is_err());
assert_eq!(h.get_str(("HISTORY", 1)).unwrap(), Some("second"));

Variants

Name(&'a str)

Match the sole keyword with this name (ambiguous if it repeats).

Nth(&'a str, usize)

Match the usize-th (0-based) occurrence of this name.

Implementations

impl<'a> Key<'a>

pub fn name(&self) -> &'a str

The keyword name this key addresses.

use xisf_header::Key;

let key: Key = ("HISTORY", 1).into();
assert_eq!(key.name(), "HISTORY");

Trait Implementations

impl<'a> Clone for Key<'a>

fn clone(&self) -> Key<'a>

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<'a> Copy for Key<'a>

impl<'a> Debug for Key<'a>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<'a> Eq for Key<'a>

impl<'a> From<&'a String> for Key<'a>

fn from(name: &'a String) -> Self

Converts to this type from the input type.

impl<'a> From<&'a str> for Key<'a>

fn from(name: &'a str) -> Self

Converts to this type from the input type.

impl<'a> From<(&'a str, usize)> for Key<'a>

fn from((name, n): (&'a str, usize)) -> Self

Converts to this type from the input type.

impl<'a> PartialEq for Key<'a>

fn eq(&self, other: &Key<'a>) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl<'a> StructuralPartialEq for Key<'a>