Struct rdfox_rs::OpenedCursor

pub struct OpenedCursor<'a> {
    pub tx: Arc<Transaction>,
    pub cursor: &'a Cursor,
    pub arity: usize,
}

Fields

tx: Arc<Transaction>

cursor: &'a Cursor

arity: usize

the arity (i.e., the number of columns) of the answers that the cursor computes.

Implementations

impl<'a> OpenedCursor<'a>

pub(crate) fn new( cursor: &'a mut Cursor, tx: Arc<Transaction> ) -> Result<(Self, usize), RDFStoreError>

Open the cursor, get the details like arity and argument info and return it as a tuple with all the details (except multiplicity) as an OpenedCursor and the multiplicity of the first row.

fn open(c_cursor: *mut CCursor) -> Result<usize, RDFStoreError>

fn arity(c_cursor: *mut CCursor) -> Result<usize, RDFStoreError>

Returns the arity (i.e., the number of columns) of the answers that the cursor computes.

pub fn advance(&mut self) -> Result<usize, RDFStoreError>

TODO: Check why this panics when called after previous call returned zero

pub fn update_and_commit<T, U>(&mut self, f: T) -> Result<U, RDFStoreError>where T: FnOnce(&mut OpenedCursor<'_>) -> Result<U, RDFStoreError>,

pub fn execute_and_rollback<T, U>(&mut self, f: T) -> Result<U, RDFStoreError>where T: FnOnce(&mut OpenedCursor<'_>) -> Result<U, RDFStoreError>,

pub fn get_answer_variable_name( &self, index: usize ) -> Result<String, RDFStoreError>

Get the variable name used in the executed SPARQL statement representing the given column in the output.

Trait Implementations

impl<'a> Debug for OpenedCursor<'a>

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

Formats the value using the given formatter.