Set the scan pointer to the previous position. Only one previous position is
remembered, and it changes with each scanning operation.
| public unscan ( ) |
public function testUnscan()
{
$s = new StringScanner('test string');
$this->assertEquals('test', $s->scan('/\\w+/'));
$s->unscan();
$this->assertEquals('te', $s->scan('/../'));
$this->assertNull($s->scan('/\\d/'));
try {
$s->unscan();
# ScanError: unscan failed: previous match record not exist
} catch (Exception $e) {
}
$this->assertNotNull($e);
$s->reset();
$this->assertEquals('test ', $s->scan('/\\w+\\s/'));
$this->assertEquals('st', $s->scan('/st/'));
$this->assertEquals('ri', $s->scan('/ri/'));
$s->unscan();
$this->assertEquals(7, $s->pos);
$this->assertEquals('ri', $s->scan('/ri/'));
}
