/**
* Constructor...
*
* @param Integer $offset The offset at which to start iteration
* @param \Traversable $inner The iterator being wrapped
*/
public function __construct($offset, \Traversable $inner)
{
$this->inner = $inner;
$offset = (int) $offset;
// If we can, be intelligent about the offset
if ($inner instanceof \Countable) {
try {
$offset = \r8\num\offsetWrap($inner->count(), $offset, \r8\num\OFFSET_NONE);
} catch (\r8\Exception\Index $err) {
$offset = NULL;
}
} else {
if ($offset < 0) {
$err = new \r8\Exception\Index($offset, "Iterator Offset", "Negative offsets are only supported if Iterator implements the Countable interface");
$err->addData("Iterator", \r8\getDump($inner));
throw $err;
}
}
$this->offset = $offset;
}
/**
* calculates the offset based on the wrap flag
*
* This is generally used by array functions to wrap offsets
*
* @param array $array The array to use as a base for calculating the offset
* @param Integer $offset The offset being wrapped
* @param Integer $wrapFlag How to handle offsets that fall outside of the
* length of the list. Allowed values are:
* - \r8\ary::OFFSET_NONE
* - \r8\ary::OFFSET_WRAP
* - \r8\ary::OFFSET_RESTRICT
* - \r8\ary::OFFSET_LIMIT
* @return Integer Returns the wrapped offset
*/
function calcOffset(array $array, $offset, $wrapFlag)
{
return \r8\num\offsetWrap(count($array), $offset, $wrapFlag);
}
function testOffsetWrap()
{
try {
\r8\num\offsetWrap(5, 2, "invalid offset value");
$this->fail('An expected exception has not been raised.');
} catch (\r8\Exception\Argument $err) {
$this->assertSame("Invalid offset wrap flag", $err->getMessage());
}
try {
\r8\num\offsetWrap(0, 2, "invalid offset value");
$this->fail('An expected exception has not been raised.');
} catch (\r8\Exception\Index $err) {
$this->assertSame("List is empty", $err->getMessage());
}
$this->assertEquals(0, \r8\num\offsetWrap(5, -5, \r8\num\OFFSET_NONE));
$this->assertEquals(3, \r8\num\offsetWrap(5, -2, \r8\num\OFFSET_NONE));
$this->assertEquals(4, \r8\num\offsetWrap(5, -1, \r8\num\OFFSET_NONE));
$this->assertEquals(0, \r8\num\offsetWrap(5, 0, \r8\num\OFFSET_NONE));
$this->assertEquals(3, \r8\num\offsetWrap(5, 3, \r8\num\OFFSET_NONE));
$this->assertEquals(4, \r8\num\offsetWrap(5, 4, \r8\num\OFFSET_NONE));
try {
\r8\num\offsetWrap(1, 2, \r8\num\OFFSET_NONE);
$this->fail('An expected exception has not been raised.');
} catch (\r8\Exception\Index $err) {
$this->assertSame("Offset is out of bounds", $err->getMessage());
}
try {
\r8\num\offsetWrap(5, 5, \r8\num\OFFSET_NONE);
$this->fail('An expected exception has not been raised.');
} catch (\r8\Exception\Index $err) {
$this->assertSame("Offset is out of bounds", $err->getMessage());
}
try {
\r8\num\offsetWrap(5, -6, \r8\num\OFFSET_NONE);
$this->fail('An expected exception has not been raised.');
} catch (\r8\Exception\Index $err) {
$this->assertSame("Offset is out of bounds", $err->getMessage());
}
$this->assertEquals(1, \r8\num\offsetWrap(5, -14, \r8\num\OFFSET_WRAP));
$this->assertEquals(2, \r8\num\offsetWrap(5, -8, \r8\num\OFFSET_WRAP));
$this->assertEquals(0, \r8\num\offsetWrap(5, -5, \r8\num\OFFSET_WRAP));
$this->assertEquals(3, \r8\num\offsetWrap(5, -2, \r8\num\OFFSET_WRAP));
$this->assertEquals(4, \r8\num\offsetWrap(5, -1, \r8\num\OFFSET_WRAP));
$this->assertEquals(0, \r8\num\offsetWrap(5, 0, \r8\num\OFFSET_WRAP));
$this->assertEquals(3, \r8\num\offsetWrap(5, 3, \r8\num\OFFSET_WRAP));
$this->assertEquals(4, \r8\num\offsetWrap(5, 4, \r8\num\OFFSET_WRAP));
$this->assertEquals(3, \r8\num\offsetWrap(5, 8, \r8\num\OFFSET_WRAP));
$this->assertEquals(0, \r8\num\offsetWrap(5, 15, \r8\num\OFFSET_WRAP));
$this->assertEquals(0, \r8\num\offsetWrap(5, -14, \r8\num\OFFSET_RESTRICT));
$this->assertEquals(0, \r8\num\offsetWrap(5, -8, \r8\num\OFFSET_RESTRICT));
$this->assertEquals(0, \r8\num\offsetWrap(5, -5, \r8\num\OFFSET_RESTRICT));
$this->assertEquals(3, \r8\num\offsetWrap(5, -2, \r8\num\OFFSET_RESTRICT));
$this->assertEquals(4, \r8\num\offsetWrap(5, -1, \r8\num\OFFSET_RESTRICT));
$this->assertEquals(0, \r8\num\offsetWrap(5, 0, \r8\num\OFFSET_RESTRICT));
$this->assertEquals(3, \r8\num\offsetWrap(5, 3, \r8\num\OFFSET_RESTRICT));
$this->assertEquals(4, \r8\num\offsetWrap(5, 4, \r8\num\OFFSET_RESTRICT));
$this->assertEquals(4, \r8\num\offsetWrap(5, 8, \r8\num\OFFSET_RESTRICT));
$this->assertEquals(4, \r8\num\offsetWrap(5, 15, \r8\num\OFFSET_RESTRICT));
$this->assertEquals(0, \r8\num\offsetWrap(5, -2, \r8\num\OFFSET_LIMIT));
$this->assertEquals(0, \r8\num\offsetWrap(5, -1, \r8\num\OFFSET_LIMIT));
$this->assertEquals(0, \r8\num\offsetWrap(5, 0, \r8\num\OFFSET_LIMIT));
$this->assertEquals(3, \r8\num\offsetWrap(5, 3, \r8\num\OFFSET_LIMIT));
$this->assertEquals(4, \r8\num\offsetWrap(5, 4, \r8\num\OFFSET_LIMIT));
$this->assertEquals(4, \r8\num\offsetWrap(5, 8, \r8\num\OFFSET_LIMIT));
$this->assertEquals(4, \r8\num\offsetWrap(5, 15, \r8\num\OFFSET_LIMIT));
}
/**
* Sets the internal result pointer to a given offset
*
* SeekableIterator interface function
*
* @param Integer $offset The offset to seek to
* @param Integer $wrapFlag How to handle offsets that fall outside of the length of the list.
* @return \r8\DB\Result\Read Returns a self reference
*/
public function seek($offset, $wrapFlag = \r8\num\OFFSET_RESTRICT)
{
if (!isset($this->adapter)) {
return $this;
}
$offset = \r8\num\offsetWrap($this->count(), $offset, $wrapFlag);
if ($offset !== FALSE && $this->pointer !== $offset) {
$this->pointer = $offset;
$this->adapter->seek($offset);
$this->row = (array) $this->adapter->fetch();
}
return $this;
}