Module functions 

Host functions: user code callable from SPARQL, Cypher and Datalog.

A host function maps RDF terms to an optional RDF term, the signature of spareval’s custom functions: None is an evaluation error, which SPARQL turns into an unbound value. Functions are registered on a store under an IRI (plus an optional Cypher name) and are never persisted: they are code, not data. Each frontend decides where the call runs — SPARQL and Cypher through the fallback evaluator, Datalog in a Rust pass over a rule’s rows — and every part of a query that does not call one still compiles to SQL.

Structs

FunctionRegistry

The host functions of a store, by IRI.

Functions

A shared, possibly absent registry: what stores hand to QueryOptions and the frontends’ options. Two handles are equal when they share one registry.

HostFunction

A function implemented by the application.

Functions

local_name

The part of an IRI after its last # or /.

Type Aliases

HostFn

The callable of a host function.