Struct DefaultGraph 

pub struct DefaultGraph;

An allocation-free singleton denoting the default graph.

Use this marker in graph slots, not as an ordinary RDF subject, predicate, or object. It has its own TermKind::DefaultGraph identity. Display and Serde use DEFAULT_GRAPH_URN for external representation; decoding an IRI as this marker requires the explicit Self::from_urn convention. Built-in owned/Cow terms implement From<DefaultGraph> without allocating.

Examples

use rdf_model::{DEFAULT_GRAPH, HeapQuad, HeapQuadPattern, HeapTerm, StatementPattern};
let pattern = HeapQuadPattern::new(None, None, None, Some(DEFAULT_GRAPH.into()));
let quad = HeapQuad::new(HeapTerm::iri("urn:s"), HeapTerm::iri("urn:p"), HeapTerm::string("o"), None);
assert!(pattern.matches_statement(&quad));
assert!(!pattern.matches_statement(&quad.with_context(HeapTerm::iri("urn:g"))));

Implementations

impl DefaultGraph

pub fn from_urn(urn: &str) -> Option<Self>

Recognizes the exact reserved URN at a boundary that opts into this convention. Returns None for any other identifier.

Trait Implementations

impl BorshDeserialize for DefaultGraph

Available on crate feature borsh only.

fn deserialize_reader<__R: Read>(reader: &mut __R) -> Result<Self, Error>

fn deserialize(buf: &mut &[u8]) -> Result<Self, Error>

Deserializes this instance from a given slice of bytes. Updates the buffer to point at the remaining bytes.

fn try_from_slice(v: &[u8]) -> Result<Self, Error>

Deserialize this instance from a slice of bytes.

fn try_from_reader<R>(reader: &mut R) -> Result<Self, Error>

where R: Read,

impl BorshSerialize for DefaultGraph

Available on crate feature borsh only.

fn serialize<__W: Write>(&self, writer: &mut __W) -> Result<(), Error>

impl Clone for DefaultGraph

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 DefaultGraph

impl Debug for DefaultGraph

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

Formats the value using the given formatter.

impl Default for DefaultGraph

fn default() -> Self

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for DefaultGraph

Available on crate feature serde only.

fn deserialize<D: Deserializer<'de>>(deserializer: D) -> Result<Self, D::Error>

Deserialize this value from the given Serde deserializer.

impl Display for DefaultGraph

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

Formats the value using the given formatter.

impl Eq for DefaultGraph

impl From<DefaultGraph> for CowTerm<'_>

Available on crate feature alloc only.

fn from(_: DefaultGraph) -> Self

Converts to this type from the input type.

impl<'a, 'b: 'a> From<DefaultGraph> for &'a CowTerm<'b>

Available on crate feature alloc only.

fn from(_: DefaultGraph) -> Self

Converts to this type from the input type.

impl From<DefaultGraph> for HeapTerm

Available on crate feature alloc only.

fn from(_: DefaultGraph) -> Self

Converts to this type from the input type.

impl From<DefaultGraph> for &HeapTerm

Available on crate feature alloc only.

fn from(_: DefaultGraph) -> Self

Converts to this type from the input type.

impl From<DefaultGraph> for &DefaultGraph

fn from(_: DefaultGraph) -> Self

Converts to this type from the input type.

impl From<DefaultGraph> for GraphName

Available on crate feature oxrdf only.

fn from(_: DefaultGraph) -> Self

Converts to this type from the input type.

impl From<DefaultGraph> for OxrdfGraphName

Available on crate feature oxrdf only.

fn from(_: DefaultGraph) -> Self

Converts to this type from the input type.

impl From<DefaultGraph> for OxrdfTerm

Available on crate feature oxrdf only.

fn from(_: DefaultGraph) -> Self

Converts to this type from the input type.

impl From<DefaultGraph> for SophiaTerm<'_>

Available on crate feature sophia only.

fn from(_: DefaultGraph) -> Self

Converts to this type from the input type.

impl Hash for DefaultGraph

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 Ord for DefaultGraph

fn cmp(&self, other: &Self) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized,

Restrict a value to a certain interval.

fn clamp_to<R>(self, range: R) -> Self

where Self: Sized, R: ClampBounds<Self>,

🔬This is a nightly-only experimental API. (clamp_to)

Restrict a value to a certain range.

impl PartialEq for DefaultGraph

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

Equality operator ==.

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

Inequality operator !=.

impl PartialOrd for DefaultGraph

fn partial_cmp(&self, other: &Self) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

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

Tests less than (for self and other) and is used by the < operator.

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

Tests less than or equal to (for self and other) and is used by the <= operator.

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

Tests greater than (for self and other) and is used by the > operator.

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

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl Serialize for DefaultGraph

Available on crate feature serde only.

fn serialize<S: Serializer>(&self, serializer: S) -> Result<S::Ok, S::Error>

Serialize this value into the given Serde serializer.

impl StructuralPartialEq for DefaultGraph

impl Term for DefaultGraph

fn kind(&self) -> TermKind

fn value_str(&self) -> Cow<'_, str>

Available on crate feature alloc only.

fn is_variable(&self) -> bool

fn is_constant(&self) -> bool

fn is_iri(&self) -> bool

fn is_bnode(&self) -> bool

fn is_literal(&self) -> bool

fn is_default_graph(&self) -> bool

Whether this term is the distinguished default-graph marker. An ordinary IRI equal to the marker’s external URN returns false.

impl Term for &DefaultGraph

fn kind(&self) -> TermKind

fn value_str(&self) -> Cow<'_, str>

Available on crate feature alloc only.

fn is_variable(&self) -> bool

fn is_constant(&self) -> bool

fn is_iri(&self) -> bool

fn is_bnode(&self) -> bool

fn is_literal(&self) -> bool

fn is_default_graph(&self) -> bool

Whether this term is the distinguished default-graph marker. An ordinary IRI equal to the marker’s external URN returns false.