/* -*- mode: c++; indent-tabs-mode: nil -*- */
/** @file QC_ObjectPairReverseIterator.qpp ObjectPairReverseIterator class definition */
/*
    Qore Programming Language

    Copyright (C) 2003 - 2023 Qore Technologies, s.r.o.

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    Note that the Qore library is released under a choice of three open-source
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*/

#include <qore/Qore.h>
#include "qore/intern/QoreObjectIterator.h"

extern QoreClass* QC_OBJECTREVERSEITERATOR;

//! This class an iterator class for objects
/** Call ObjectPairReverseIterator::next() to iterate through the object in reverse order; do not use the iterator if ObjectPairReverseIterator::next() returns @ref False.
    A object can be iterated in reverse order by calling ObjectPairReverseIterator::prev() instead of ObjectPairReverseIterator::next()

    @par Example: ObjectPairReverseIterator basic usage
    @code{.py}
    class Class1 {
       public {
          int attr1;
          date attr2;
       }
       constructor() {
          attr1 = 1;
          attr2 = now();
       }
    }
    Class1 o();

    ObjectPairReverseIterator it(o);
    while (it.next()) {
        printf("iter: %n\n", it.getValue());
    }

    iter: hash: (key : "attr2", value : 2013-04-17 16:38:31 Wed +02:00 (CEST))
    iter: hash: (key : "attr1", value : 1)
    @endcode

    @note
    - In general, the ObjectPairReverseIterator class is not designed to be accessed from multiple threads; it was created without locking for
      fast and efficient use when used from a single thread.  For methods that would be unsafe to use in another thread, any use of
      such methods in threads other than the thread where the constructor was called will cause an \c ITERATOR-THREAD-ERROR to be thrown.
    - ObjectPairReverseIterator is functionally equivalent to ObjectPairIterator, but the effect of ObjectPairReverseIterator::next() and ObjectPairReverseIterator::prev()
      are the opposite of ObjectPairIterator::next() and ObjectPairIterator::prev(); that is ObjectPairReverseIterator::next() will
      iterate through the object in reverse order, while ObjectPairReverseIterator::prev() iterates in forward order.
      Additionally the meanings of the return values for ObjectPairReverseIterator::first() and ObjectPairReverseIterator::last()
      are swapped in respect to ObjectPairIterator::first() and ObjectPairIterator::last().

    @see ObjectPairIterator
 */
qclass ObjectPairReverseIterator [arg=QoreObjectReverseIterator* i; ns=Qore; vparent=ObjectReverseIterator];

//! Creates the object iterator object
/** @param o the object to iterate

    @par Example:
    @code{.py}
ObjectPairReverseIterator i(obj);
    @endcode
 */
ObjectPairReverseIterator::constructor(object o) {
   self->setPrivate(CID_OBJECTPAIRREVERSEITERATOR, new QoreObjectReverseIterator(o));
}

//! Creates an empty iterator object
/** @par Example:
    @code{.py}
*object obj = get_object_or_nothing();
ObjectPairReverseIterator i(obj);
    @endcode
 */
ObjectPairReverseIterator::constructor() {
   self->setPrivate(CID_OBJECTPAIRREVERSEITERATOR, new QoreObjectReverseIterator);
}

//! Creates a copy of the ObjectPairReverseIterator object, iterating the same object as the original and in the same position
/** @par Example:
    @code{.py}
ObjectPairReverseIterator ni = i.copy();
    @endcode
 */
ObjectPairReverseIterator::copy() {
   self->setPrivate(CID_OBJECTPAIRREVERSEITERATOR, new QoreObjectReverseIterator(*i));
}

//! returns a hash with the current key and value (a hash with 2 keys: \c "key" and \c "value") or throws an \c INVALID-ITERATOR exception if the iterator is invalid
/** @return a hash with the current key and value (a hash with 2 keys: \c "key" and \c "value") or throws an \c INVALID-ITERATOR exception if the iterator is invalid

    @par Example:
    @code{.py}
foreach hash<auto> h in (new ObjectPairReverseIterator(obj))
    printf("%s: %y\n", h.key, h.value);
    @endcode

    @throw INVALID-ITERATOR the iterator is not pointing at a valid element
    @throw ITERATOR-THREAD-ERROR this exception is thrown if this method is called from any thread other than the thread that created the object

    @since %Qore 0.8.6.2
 */
hash<auto> ObjectPairReverseIterator::getValue() [flags=RET_VALUE_ONLY] {
    if (i->check(xsink))
        return QoreValue();
    return i->getReferencedValuePair(xsink);
}
