dockerwiki/content/inc/Parsing/Lexer/StateStack.php
2021-10-26 13:02:53 +02:00

61 lines
1.3 KiB
PHP

<?php
/**
* Lexer adapted from Simple Test: http://sourceforge.net/projects/simpletest/
* For an intro to the Lexer see:
* https://web.archive.org/web/20120125041816/http://www.phppatterns.com/docs/develop/simple_test_lexer_notes
*
* @author Marcus Baker http://www.lastcraft.com
*/
namespace dokuwiki\Parsing\Lexer;
/**
* States for a stack machine.
*/
class StateStack
{
protected $stack;
/**
* Constructor. Starts in named state.
* @param string $start Starting state name.
*/
public function __construct($start)
{
$this->stack = array($start);
}
/**
* Accessor for current state.
* @return string State.
*/
public function getCurrent()
{
return $this->stack[count($this->stack) - 1];
}
/**
* Adds a state to the stack and sets it to be the current state.
*
* @param string $state New state.
*/
public function enter($state)
{
array_push($this->stack, $state);
}
/**
* Leaves the current state and reverts
* to the previous one.
* @return boolean false if we attempt to drop off the bottom of the list.
*/
public function leave()
{
if (count($this->stack) == 1) {
return false;
}
array_pop($this->stack);
return true;
}
}