#include <Soprano/StatementIterator>
Public Member Functions | |
StatementIterator () | |
StatementIterator (IteratorBackend< Statement > *sti) | |
StatementIterator (const StatementIterator &sti) | |
virtual | ~StatementIterator () |
StatementIterator & | operator= (const StatementIterator &) |
QList< Statement > | allStatements () |
NodeIterator | iterateSubjects () const |
NodeIterator | iteratePredicates () const |
NodeIterator | iterateObjects () const |
NodeIterator | iterateContexts () const |
The most common use of StatementIterator is through Model::listStatements().
Many backends do lock the underlying Model during iteration. Thus, it is always a good idea to cache the results if they are to be used to modify the model to prevent a deadlock:
Soprano::StatementIterator it = model->listStatements(); QList<Statement> allStatements = it.allElements(); Q_FOREACH( Soprano::Statement s, allStatements ) { modifyTheModel( model, s ); }
Iterators have to be closed. This can either be achieved by deleting the iterator, finishing it (next() does return false
), or calling close(). Before that other operations on the Model may block.
Iterators are not thread-safe. Two threads using the same iterator at the same time may result in undefined behaviour and even crashes.
Definition at line 73 of file statementiterator.h.
Soprano::StatementIterator::StatementIterator | ( | ) |
Creates and empty, invalid iterator.
Soprano::StatementIterator::StatementIterator | ( | IteratorBackend< Statement > * | sti | ) |
Create a new StatementIterator instance that uses sti as backend. StatementIterator will take ownership of the backend.
Soprano::StatementIterator::StatementIterator | ( | const StatementIterator & | sti | ) |
virtual Soprano::StatementIterator::~StatementIterator | ( | ) | [virtual] |
StatementIterator& Soprano::StatementIterator::operator= | ( | const StatementIterator & | ) |
Convenience method which extracts all statements (this does not include the statements that have already been read from the iterator) from the iterator and returns them in a list.
Be aware that after calling this method the iterator will be invalid.
Definition at line 102 of file statementiterator.h.
NodeIterator Soprano::StatementIterator::iterateSubjects | ( | ) | const |
Convenience method that creates an iterator over the subject nodes of the statements in this iterator.
NodeIterator Soprano::StatementIterator::iteratePredicates | ( | ) | const |
Convenience method that creates an iterator over the predicate nodes of the statements in this iterator.
NodeIterator Soprano::StatementIterator::iterateObjects | ( | ) | const |
Convenience method that creates an iterator over the object nodes of the statements in this iterator.
NodeIterator Soprano::StatementIterator::iterateContexts | ( | ) | const |
Convenience method that creates an iterator over the context nodes of the statements in this iterator.