From 0f321595ca5166f585b6fad6c2e0e68f1de0c7dc Mon Sep 17 00:00:00 2001
From: Kevin Chabowski <kevin@kch42.de>
Date: Thu, 1 Sep 2011 23:55:20 +0200
Subject: Initial commit of stupid_template_engine.

Parser finished :-D
---
 transform.php | 194 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 194 insertions(+)
 create mode 100644 transform.php

(limited to 'transform.php')

diff --git a/transform.php b/transform.php
new file mode 100644
index 0000000..788b5fd
--- /dev/null
+++ b/transform.php
@@ -0,0 +1,194 @@
+<?php
+
+class TextNode
+{
+	public $text;
+}
+
+class TagNode
+{
+	public $name;
+	public $params;
+	public $sub;
+}
+
+class VariableNode
+{
+	public $name;
+	public $arrayfields;
+}
+
+/* $text must start after the first opening bracket */
+function find_closing_bracket($text, $opening, $closing)
+{
+	$counter = 1;
+	$len = strlen($text);
+	for($i = 0; $i < $len; ++$i)
+	{
+		switch($text[$i])
+		{
+			case $opening:
+				++$counter;
+				break;
+			case $closing:
+				--$counter;
+				break;
+		}
+		if($counter == 0)
+			break;
+	}
+	
+	if($counter > 0)
+		throw new Exception("Missing closing \"$closing\". Stop.");
+	
+	return $i;
+}
+
+function unescape_text($text)
+{
+	$text = preg_replace("/(?:(?<!\\\\)\\\\\\\$)/s", "$", $text);
+	return str_replace("\\\\", "\\", $text);
+}
+
+function tokenize_text($text)
+{
+	$tokens = array();
+	/* Find next non-escaped $-char */
+	if(preg_match("/(?:(?<!\\\\)\\$)/s", $text, $match, PREG_OFFSET_CAPTURE) == 0)
+	{
+		$node = new TextNode();
+		$node->text = unescape_text($text);
+		return (strlen($node->text) == 0) ? array() : array($node);
+	}
+	
+	if($match[0][1] > 0)
+	{
+		$node = new TextNode();
+		$node->text = unescape_text(substr($text, 0, $match[0][1]));
+		$tokens[] = $node;
+	}
+	
+	if($text[$match[0][1] + 1] == "{")
+	{
+		$varend = find_closing_bracket(substr($text, $match[0][1] + 2), "{", "}") + $match[0][1] + 2;
+		return array_merge(
+			$tokens,
+			tokenize_text("\$" . substr($text, $match[0][1] + 2, ($varend - 1) - ($match[0][1] + 1))),
+			tokenize_text(substr($text, $varend + 1))
+		);
+	}
+	
+	$text = substr($text, $match[0][1] + 1);
+	if(preg_match("/^[a-zA-Z0-9_]+/s", $text, $match, PREG_OFFSET_CAPTURE) == 0)
+	{
+		$nexttokens = tokenize_text($text);
+		if($nexttokens[0] instanceof Text)
+			$nexttokens[0]->text = "\$" . $nexttokens[0]->text;
+		else
+		{
+			$node = new TextNode();
+			$node->text = "\$";
+			$tokens[] = $node;
+		}
+		return array_merge($tokens, $nexttokens);
+	}
+	
+	$node = new VariableNode();
+	$node->name = $match[0][0];
+	$node->arrayfields = array();
+	
+	$text = substr($text, $match[0][1] + strlen($match[0][0]));
+	while(@$text[0] == "[")
+	{
+		$text = substr($text, 1);
+		$fieldend = find_closing_bracket($text, "[", "]");
+		$node->arrayfields[] = tokenize_text(substr($text, 0, $fieldend));
+		$text = substr($text, $fieldend + 1);
+	}
+	
+	$tokens[] = $node;
+	
+	return strlen($text) > 0 ? array_merge($tokens, tokenize_text($text)) : $tokens;
+}
+
+function mk_ast($code)
+{
+	$ast = array();
+	
+	if(preg_match("/\\<\\s*ste:([a-zA-Z0-9_]*)/s", $code, $matches, PREG_OFFSET_CAPTURE) == 0)
+		return tokenize_text($code);
+	
+	$ast = tokenize_text(substr($code, 0, $matches[0][1]));
+	
+	$tag = new TagNode();
+	$tag->name = $matches[1][0];
+	
+	$code = substr($code, $matches[0][1] + strlen($matches[0][0]));
+	
+	$tag->params = array();
+	
+	while(preg_match("/^\\s+([a-zA-Z0-9_]+)=((?:\"(?:.*?)(?<!\\\\)\")|(?:'(?:.*?)(?<!\\\\)'))/s", $code, $matches, PREG_OFFSET_CAPTURE) > 0)
+	{
+		$paramval = substr($code, $matches[2][1] + 1, strlen($matches[2][0]) - 2);
+		$paramval = str_replace("\\\"", "\"", $paramval);
+		$paramval = str_replace("\\'", "'", $paramval);
+		$tag->params[$matches[1][0]] = tokenize_text($paramval);
+		$code = substr($code, strlen($matches[0][0]));
+	}
+	
+	if(preg_match("/^\\s*([\\/]?)\\s*\\>/s", $code, $matches) == 0)
+		throw new Exception("Missing closing '>' in \"" . $tag->name . "\"-Tag. Stop. (:::CODE START:::$code:::CODE END:::)");
+	
+	$code = substr($code, strlen($matches[0]));
+	
+	$tag->sub = array();
+	
+	if($matches[1][0] != "/")
+	{
+		$tags_open = 1;
+		$off = 0;
+		$last_tag_start = 0;
+		while(preg_match("/\\<((?:\\s*)|(?:\\s*\\/\\s*))ste:([a-zA-Z0-9_]*)(?:\\s+(?:[a-zA-Z0-9_]+)=(?:(?:\"(?:.*?)(?<!\\\\)\")|(?:'(?:.*?)(?<!\\\\)')))*\\s*(?<!\\/)\\>/s", $code, $matches, PREG_OFFSET_CAPTURE, $off) > 0) /* RegEx from hell! Matches all non-selfclosing <ste:> Tags. Opening and closing ones. */
+		{
+			$closingtag = trim($matches[1][0]);
+			if($closingtag[0] == "/")
+				$tags_open--;
+			else
+				$tags_open++;
+			$last_tag_start = $matches[0][1];
+			$off = $last_tag_start + strlen($matches[0][0]);
+			if($tags_open == 0)
+				break;
+		}
+		
+		if(($tags_open != 0) or ($tag->name != $matches[2][0]))
+			throw new Exception("Missing closing \"ste:" + $tag->name + "\"-Tag. Stop.");
+		
+		$tag->sub = mk_ast(substr($code, 0, $last_tag_start));
+		$code = substr($code, $off);
+	}
+	
+	$ast[] = $tag;
+	return array_merge($ast, strlen($code) > 0 ? mk_ast($code) : array());
+}
+
+function parse($code)
+{
+	/* Precompiling... */
+	$code = preg_replace("/\\<\\s*ste:comment\\s*\\>.*?\\<\\s*\\/\\s*ste:comment\\s*\\>/s", "", $code); /* Remove comments */
+	$code = preg_replace( /* Transform short form of if-clause (?{cond|then|else}) to long form */
+		"/(?:(?<!\\\\)\\?)(?:(?<!\\\\)\\{)(.*?)(?:(?<!\\\\)\\|)(.*?)(?:(?<!\\\\)\\|)(.*?)(?:(?<!\\\\)\\})/s",
+		"<ste:if>\$1<ste:then>\$2</ste:then><ste:else>\$3</ste:else></ste:if>",
+		$code
+	);
+	/* Unescape \? \{ \} \| */
+	$code = preg_replace("/(?:(?<!\\\\)\\\\\\?)/s", "?", $code);
+	$code = preg_replace("/(?:(?<!\\\\)\\\\\\{)/s", "{", $code);
+	$code = preg_replace("/(?:(?<!\\\\)\\\\\\})/s", "}", $code);
+	$code = preg_replace("/(?:(?<!\\\\)\\\\\\|)/s", "|", $code);
+	
+	/* Create abstract syntax tree */
+	return mk_ast($code);
+}
+
+?>
-- 
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