Struct HostFunction 

pub struct HostFunction { /* private fields */ }

A function implemented by the application.

Implementations

impl HostFunction

pub fn new( iri: impl Into<String>, f: impl Fn(&[Term]) -> Option<Term> + Send + Sync + 'static, ) -> Self

A function named by iri (checked when it is registered).

pub fn cypher_name(self, name: impl Into<String>) -> Self

The name Cypher calls it by (default: the local name of the IRI).

pub fn arity(self, min: usize, max: impl Into<Option<usize>>) -> Self

How many arguments it takes; a call with another number is an evaluation error.

pub fn description(self, text: impl Into<String>) -> Self

A one-line description, shown by tools (completion, .functions).

pub fn iri(&self) -> &str

pub fn cypher(&self) -> &str

The name Cypher calls it by: the explicit one, else the IRI’s local name.

pub fn min_arity(&self) -> usize

pub fn max_arity(&self) -> Option<usize>

pub fn description_text(&self) -> &str

pub fn call(&self, args: &[Term]) -> Option<Term>

Calls the function; a wrong number of arguments is an evaluation error (None).

pub fn callable( &self, ) -> impl Fn(&[Term]) -> Option<Term> + Send + Sync + 'static

The callable, arity check included, as spareval takes it.

Trait Implementations

impl Clone for HostFunction

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for HostFunction

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

Formats the value using the given formatter.