Enum BlankNodeMatchingMode 

pub enum BlankNodeMatchingMode {
    Variable,
    Filter,
}

Specifies how blank nodes should be matched.

Blank nodes are scoped to a single graph. Users must choose whether a blank node in a pattern should only match blank nodes with the same label in the graph or match any node (like a variable).

In SPARQL queries, this strict matching is generally not desired because the blank nodes in the query are different from the blank nodes in the graph (even if they have the same label!). In this case, blank nodes in the query should be treated as variables and can therefore match any node in the graph.

However, if the goal is to retrieve all quads with a specific blank node as the subject, it may be appropriate to only match the blank node with that exact label in the graph.

Examples:

Mode	To Match	In Graph	Matches?
Variable	_:a	_:a	Yes
Variable	_:a	_:b	Yes
Filter	_:a	_:a	Yes
Filter	_:a	_:b	No

Variants

Variable

Treat blank nodes as variables.

Filter

Treat blank nodes as a specific, constant filter (exact label match).

Trait Implementations

impl Clone for BlankNodeMatchingMode

fn clone(&self) -> BlankNodeMatchingMode

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for BlankNodeMatchingMode

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

Formats the value using the given formatter.

impl Default for BlankNodeMatchingMode

fn default() -> BlankNodeMatchingMode

Returns the “default value” for a type.

impl Hash for BlankNodeMatchingMode

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

where __H: Hasher,

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 BlankNodeMatchingMode

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

Tests for self and other values to be equal, and is used by ==.

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

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Copy for BlankNodeMatchingMode

impl Eq for BlankNodeMatchingMode

impl StructuralPartialEq for BlankNodeMatchingMode