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PropertyFunction

oxirs_core::query::property_function_registry

Trait PropertyFunction 

Source 
pub trait PropertyFunction:
    Send
    + Sync
    + Debug {
    // Required methods
    fn metadata(&self) -> PropertyFunctionMetadata;
    fn evaluate(
        &self,
        subject: &PropertyFunctionArg,
        object: &PropertyFunctionArg,
    ) -> Result<PropertyFunctionResult, OxirsError>;

    // Provided methods
    fn validate(
        &self,
        subject: &PropertyFunctionArg,
        object: &PropertyFunctionArg,
    ) -> Result<(), OxirsError> { ... }
    fn estimated_cardinality(
        &self,
        _subject: &PropertyFunctionArg,
        _object: &PropertyFunctionArg,
    ) -> Option<u64> { ... }
}
Expand description

Core trait for property function implementations.

A property function is invoked when the SPARQL engine encounters a triple pattern whose predicate matches a registered IRI.

Required Methods§

Source

fn metadata(&self) -> PropertyFunctionMetadata

Return metadata describing this property function.

Source

fn evaluate( &self, subject: &PropertyFunctionArg, object: &PropertyFunctionArg, ) -> Result<PropertyFunctionResult, OxirsError>

Evaluate the property function given the subject and object arguments.

§Arguments
  • subject - The subject side of the triple pattern
  • object - The object side of the triple pattern
§Returns

A set of bindings produced by the evaluation.

Provided Methods§

Source

fn validate( &self, subject: &PropertyFunctionArg, object: &PropertyFunctionArg, ) -> Result<(), OxirsError>

Validate arguments before evaluation (optional override).

Source

fn estimated_cardinality( &self, _subject: &PropertyFunctionArg, _object: &PropertyFunctionArg, ) -> Option<u64>

Estimated cardinality of results (for query planning). Returns None if unknown. Default is None.

Dyn Compatibility§

This trait is dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementors§