Qore::SingleValueIterator Class Reference

This class defines a simple iterator to be used to iterate single values (or complex objects where no iterator has been implemented yet) More...

#include <QC_SingleValueIterator.dox.h>

Inheritance diagram for Qore::SingleValueIterator:

Public Member Methods
	constructor (auto v)
	creates the single value iterator with the value passed as an argument
	copy ()
	Creates a copy of the SingleValueIterator object, iterating the same object as the original and in the same position.
auto	getValue ()
	returns the current value or throws an INVALID-ITERATOR exception if the iterator is invalid
bool	next ()
	This method returns True and False alternately unless it has no value to iterate, in which case it returns only False.
	reset ()
	Reset the iterator instance to its initial state.
bool	valid ()
	returns True if the iterator is currently pointing at a valid element, False if not
Public Member Methods inherited from Qore::AbstractIterator
abstract auto	getValue ()
	returns the current value
abstract bool	next ()
	Moves the current position to the next element; returns False if there are no more elements.
abstract bool	valid ()
	returns True if the iterator is currently pointing at a valid element, False if not

Detailed Description

This class defines a simple iterator to be used to iterate single values (or complex objects where no iterator has been implemented yet)

Since

Qore 0.8.6

Example: SingleValueIterator basic usage

auto val = 1;
SingleValueIterator it(val);
while (it.next()) {
    printf("iter: %n\n", it.getValue());
}
 
iter: 1

Remember that input value is taken as a single token so result of the code above for a list as an input argument will be like this:

auto val = (1, 2, 3);
iter: list: (1, 2, 3)

Member Function Documentation

constructor()

Qore::SingleValueIterator::constructor

(

auto

v

)

creates the single value iterator with the value passed as an argument

Parameters

v	the value to iterate

Example:

SingleValueIterator i(v);

copy()

Qore::SingleValueIterator::copy

(

)

Creates a copy of the SingleValueIterator object, iterating the same object as the original and in the same position.

Example:

SingleValueIterator ni = i.copy();

getValue()

auto Qore::SingleValueIterator::getValue

(

)

returns the current value or throws an INVALID-ITERATOR exception if the iterator is invalid

Returns

the current value or throws an INVALID-ITERATOR exception if the iterator is invalid

Code Flags:

RET_VALUE_ONLY

Example:

while (i.next()) {
    printf("+ %y\n", i.getValue());
}

Exceptions

INVALID-ITERATOR

the iterator is not pointing at a valid element

next()

bool Qore::SingleValueIterator::next

(

)

This method returns True and False alternately unless it has no value to iterate, in which case it returns only False.

The iterator object should not be used after this method returns False

Returns

True and False alternately unless it has no value to iterate, in which case it returns only False

Example:

while (i.next()) {
    printf("value: %y\n", i.getValue());
}

Exceptions

ITERATOR-THREAD-ERROR

this exception is thrown if this method is called from any thread other than the thread that created the object

reset()

Qore::SingleValueIterator::reset

(

)

Reset the iterator instance to its initial state.

Reset the iterator instance to its initial state

Example

i.reset();

Exceptions

ITERATOR-THREAD-ERROR

this exception is thrown if this method is called from any thread other than the thread that created the object

valid()

bool Qore::SingleValueIterator::valid

(

)

returns True if the iterator is currently pointing at a valid element, False if not

Returns

True if the iterator is currently pointing at a valid element, False if not

Code Flags:

CONSTANT

Example:

if (i.valid())
    printf("current value: %y\n", i.getValue());