Enum Occurrence 

pub enum Occurrence {
    Required,
    Prohibited,
    Optional,
}

What a requirement demands of the elements a specification applies to.

This is the normalised form: from_xs_occurs lowers the 0.9 spelling and from_cardinality the 1.0 spelling, so equal intent compares equal across revisions.

Variants

Required

The facet must be present. The 1.0 required cardinality, and the 0.9 spelling minOccurs >= 1.

Prohibited

The facet must be absent. The 1.0 prohibited cardinality, and the 0.9 spelling maxOccurs = 0.

Optional

The facet may be present or absent. The 1.0 optional cardinality, and the 0.9 spelling minOccurs = 0 with a non-zero maxOccurs.

Implementations

impl Occurrence

pub const DEFAULT: Occurrence = Occurrence::Required

The schema default.

Load-bearing, and the reason it is named rather than left implicit: real IDS files lean on it. A facet writing no @cardinality at all means required, so a reader that treats “absent” as “optional” silently drops requirements.

pub fn from_cardinality(value: &str) -> Option<Occurrence>

Lowers the IDS 1.0 @cardinality attribute.

use openbim_ids::Occurrence;
assert_eq!(Occurrence::from_cardinality("prohibited"), Some(Occurrence::Prohibited));
assert_eq!(Occurrence::from_cardinality("Required"), None);

Matching is case-sensitive because the schema enumerates lower-case tokens; accepting other spellings would mean accepting documents the schema rejects.

pub fn as_cardinality(self) -> &'static str

The IDS 1.0 @cardinality spelling of this occurrence.

pub fn from_xs_occurs(min: u32, max: Option<u32>) -> Occurrence

Lowers the IDS 0.9 xs:occurs spelling.

max is None for maxOccurs="unbounded". Absent attributes must be passed as their schema defaults of 1, not as 0 — see Occurrence::DEFAULT.

use openbim_ids::Occurrence;
// The 0.9 and 1.0 spellings of the same intent agree.
assert_eq!(
    Occurrence::from_xs_occurs(0, Some(0)),
    Occurrence::from_cardinality("prohibited").unwrap()
);
assert_eq!(Occurrence::from_xs_occurs(1, None), Occurrence::Required);

pub fn permits_presence(self) -> bool

Whether the facet is allowed to appear at all.

Trait Implementations

impl Clone for Occurrence

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for Occurrence

impl Debug for Occurrence

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

Formats the value using the given formatter.

impl Default for Occurrence

fn default() -> Self

Returns the “default value” for a type.

impl Display for Occurrence

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

Formats the value using the given formatter.

impl Eq for Occurrence

impl Hash for Occurrence

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for Occurrence

fn eq(&self, other: &Self) -> bool

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for Occurrence