Initial commit

content/inc/Parsing/Lexer/StateStack.php

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+<?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;
+    }
+}