public function testFnCounter()
{
$fn = FnGen::fnCounter(0);
$this->assertTrue($fn() == 0);
$this->assertTrue($fn() == 1);
$this->assertTrue($fn() == 2);
$this->assertTrue($fn() == 3);
$fn = FnGen::fnCounter(10);
$this->assertTrue($fn() == 10);
$this->assertTrue($fn() == 11);
$this->assertTrue($fn() == 12);
$this->assertTrue($fn() == 13);
}
/**
* @param Iterator $iterator
* @return MappedSequence
*/
public static function sequenceNumericKeys(Iterator $iterator)
{
return new MappedSequence($iterator, FnGen::fnIdentity(), FnGen::fnIfMap(FnGen::fnIsNumeric(), FnGen::fnCounter(), FnGen::fnIdentity()));
}
