diff -r 6d109e3804ac -r 9a001a04b634 Twig-1.3.0/lib/Twig/ExpressionParser.php
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Twig-1.3.0/lib/Twig/ExpressionParser.php	Tue Oct 25 23:56:28 2011 +0200
@@ -0,0 +1,382 @@
+<?php
+
+/*
+ * This file is part of Twig.
+ *
+ * (c) 2009 Fabien Potencier
+ * (c) 2009 Armin Ronacher
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+/**
+ * Parses expressions.
+ *
+ * This parser implements a "Precedence climbing" algorithm.
+ *
+ * @see http://www.engr.mun.ca/~theo/Misc/exp_parsing.htm
+ * @see http://en.wikipedia.org/wiki/Operator-precedence_parser
+ *
+ * @package    twig
+ * @author     Fabien Potencier <fabien@symfony.com>
+ */
+class Twig_ExpressionParser
+{
+    const OPERATOR_LEFT = 1;
+    const OPERATOR_RIGHT = 2;
+
+    protected $parser;
+    protected $unaryOperators;
+    protected $binaryOperators;
+
+    public function __construct(Twig_Parser $parser, array $unaryOperators, array $binaryOperators)
+    {
+        $this->parser = $parser;
+        $this->unaryOperators = $unaryOperators;
+        $this->binaryOperators = $binaryOperators;
+    }
+
+    public function parseExpression($precedence = 0)
+    {
+        $expr = $this->getPrimary();
+        $token = $this->parser->getCurrentToken();
+        while ($this->isBinary($token) && $this->binaryOperators[$token->getValue()]['precedence'] >= $precedence) {
+            $op = $this->binaryOperators[$token->getValue()];
+            $this->parser->getStream()->next();
+
+            if (isset($op['callable'])) {
+                $expr = call_user_func($op['callable'], $this->parser, $expr);
+            } else {
+                $expr1 = $this->parseExpression(self::OPERATOR_LEFT === $op['associativity'] ? $op['precedence'] + 1 : $op['precedence']);
+                $class = $op['class'];
+                $expr = new $class($expr, $expr1, $token->getLine());
+            }
+
+            $token = $this->parser->getCurrentToken();
+        }
+
+        if (0 === $precedence) {
+            return $this->parseConditionalExpression($expr);
+        }
+
+        return $expr;
+    }
+
+    protected function getPrimary()
+    {
+        $token = $this->parser->getCurrentToken();
+
+        if ($this->isUnary($token)) {
+            $operator = $this->unaryOperators[$token->getValue()];
+            $this->parser->getStream()->next();
+            $expr = $this->parseExpression($operator['precedence']);
+            $class = $operator['class'];
+
+            return $this->parsePostfixExpression(new $class($expr, $token->getLine()));
+        } elseif ($token->test(Twig_Token::PUNCTUATION_TYPE, '(')) {
+            $this->parser->getStream()->next();
+            $expr = $this->parseExpression();
+            $this->parser->getStream()->expect(Twig_Token::PUNCTUATION_TYPE, ')', 'An opened parenthesis is not properly closed');
+
+            return $this->parsePostfixExpression($expr);
+        }
+
+        return $this->parsePrimaryExpression();
+    }
+
+    protected function parseConditionalExpression($expr)
+    {
+        while ($this->parser->getStream()->test(Twig_Token::PUNCTUATION_TYPE, '?')) {
+            $this->parser->getStream()->next();
+            $expr2 = $this->parseExpression();
+            $this->parser->getStream()->expect(Twig_Token::PUNCTUATION_TYPE, ':', 'The ternary operator must have a default value');
+            $expr3 = $this->parseExpression();
+
+            $expr = new Twig_Node_Expression_Conditional($expr, $expr2, $expr3, $this->parser->getCurrentToken()->getLine());
+        }
+
+        return $expr;
+    }
+
+    protected function isUnary(Twig_Token $token)
+    {
+        return $token->test(Twig_Token::OPERATOR_TYPE) && isset($this->unaryOperators[$token->getValue()]);
+    }
+
+    protected function isBinary(Twig_Token $token)
+    {
+        return $token->test(Twig_Token::OPERATOR_TYPE) && isset($this->binaryOperators[$token->getValue()]);
+    }
+
+    public function parsePrimaryExpression()
+    {
+        $token = $this->parser->getCurrentToken();
+        switch ($token->getType()) {
+            case Twig_Token::NAME_TYPE:
+                $this->parser->getStream()->next();
+                switch ($token->getValue()) {
+                    case 'true':
+                    case 'TRUE':
+                        $node = new Twig_Node_Expression_Constant(true, $token->getLine());
+                        break;
+
+                    case 'false':
+                    case 'FALSE':
+                        $node = new Twig_Node_Expression_Constant(false, $token->getLine());
+                        break;
+
+                    case 'none':
+                    case 'NONE':
+                    case 'null':
+                    case 'NULL':
+                        $node = new Twig_Node_Expression_Constant(null, $token->getLine());
+                        break;
+
+                    default:
+                        if ('(' === $this->parser->getCurrentToken()->getValue()) {
+                            $node = $this->getFunctionNode($token->getValue(), $token->getLine());
+                        } else {
+                            $node = new Twig_Node_Expression_Name($token->getValue(), $token->getLine());
+                        }
+                }
+                break;
+
+            case Twig_Token::NUMBER_TYPE:
+            case Twig_Token::STRING_TYPE:
+                $this->parser->getStream()->next();
+                $node = new Twig_Node_Expression_Constant($token->getValue(), $token->getLine());
+                break;
+
+            default:
+                if ($token->test(Twig_Token::PUNCTUATION_TYPE, '[')) {
+                    $node = $this->parseArrayExpression();
+                } elseif ($token->test(Twig_Token::PUNCTUATION_TYPE, '{')) {
+                    $node = $this->parseHashExpression();
+                } else {
+                    throw new Twig_Error_Syntax(sprintf('Unexpected token "%s" of value "%s"', Twig_Token::typeToEnglish($token->getType(), $token->getLine()), $token->getValue()), $token->getLine());
+                }
+        }
+
+        return $this->parsePostfixExpression($node);
+    }
+
+    public function parseArrayExpression()
+    {
+        $stream = $this->parser->getStream();
+        $stream->expect(Twig_Token::PUNCTUATION_TYPE, '[', 'An array element was expected');
+        $elements = array();
+        while (!$stream->test(Twig_Token::PUNCTUATION_TYPE, ']')) {
+            if (!empty($elements)) {
+                $stream->expect(Twig_Token::PUNCTUATION_TYPE, ',', 'An array element must be followed by a comma');
+
+                // trailing ,?
+                if ($stream->test(Twig_Token::PUNCTUATION_TYPE, ']')) {
+                    break;
+                }
+            }
+
+            $elements[] = $this->parseExpression();
+        }
+        $stream->expect(Twig_Token::PUNCTUATION_TYPE, ']', 'An opened array is not properly closed');
+
+        return new Twig_Node_Expression_Array($elements, $stream->getCurrent()->getLine());
+    }
+
+    public function parseHashExpression()
+    {
+        $stream = $this->parser->getStream();
+        $stream->expect(Twig_Token::PUNCTUATION_TYPE, '{', 'A hash element was expected');
+        $elements = array();
+        while (!$stream->test(Twig_Token::PUNCTUATION_TYPE, '}')) {
+            if (!empty($elements)) {
+                $stream->expect(Twig_Token::PUNCTUATION_TYPE, ',', 'A hash value must be followed by a comma');
+
+                // trailing ,?
+                if ($stream->test(Twig_Token::PUNCTUATION_TYPE, '}')) {
+                    break;
+                }
+            }
+
+            if (!$stream->test(Twig_Token::STRING_TYPE) && !$stream->test(Twig_Token::NUMBER_TYPE)) {
+                $current = $stream->getCurrent();
+                throw new Twig_Error_Syntax(sprintf('A hash key must be a quoted string or a number (unexpected token "%s" of value "%s"', Twig_Token::typeToEnglish($current->getType(), $current->getLine()), $current->getValue()), $current->getLine());
+            }
+
+            $key = $stream->next()->getValue();
+            $stream->expect(Twig_Token::PUNCTUATION_TYPE, ':', 'A hash key must be followed by a colon (:)');
+            $elements[$key] = $this->parseExpression();
+        }
+        $stream->expect(Twig_Token::PUNCTUATION_TYPE, '}', 'An opened hash is not properly closed');
+
+        return new Twig_Node_Expression_Array($elements, $stream->getCurrent()->getLine());
+    }
+
+    public function parsePostfixExpression($node)
+    {
+        while (true) {
+            $token = $this->parser->getCurrentToken();
+            if ($token->getType() == Twig_Token::PUNCTUATION_TYPE) {
+                if ('.' == $token->getValue() || '[' == $token->getValue()) {
+                    $node = $this->parseSubscriptExpression($node);
+                } elseif ('|' == $token->getValue()) {
+                    $node = $this->parseFilterExpression($node);
+                } else {
+                    break;
+                }
+            } else {
+                break;
+            }
+        }
+
+        return $node;
+    }
+
+    public function getFunctionNode($name, $line)
+    {
+        $args = $this->parseArguments();
+        switch ($name) {
+            case 'parent':
+                if (!count($this->parser->getBlockStack())) {
+                    throw new Twig_Error_Syntax('Calling "parent" outside a block is forbidden', $line);
+                }
+
+                if (!$this->parser->getParent() && !$this->parser->hasTraits()) {
+                    throw new Twig_Error_Syntax('Calling "parent" on a template that does not extend nor "use" another template is forbidden', $line);
+                }
+
+                return new Twig_Node_Expression_Parent($this->parser->peekBlockStack(), $line);
+            case 'block':
+                return new Twig_Node_Expression_BlockReference($args->getNode(0), false, $line);
+            case 'attribute':
+                if (count($args) < 2) {
+                    throw new Twig_Error_Syntax('The "attribute" function takes at least two arguments (the variable and the attribute)', $line);
+                }
+
+                return new Twig_Node_Expression_GetAttr($args->getNode(0), $args->getNode(1), count($args) > 2 ? $args->getNode(2) : new Twig_Node_Expression_Array(array(), $line), Twig_TemplateInterface::ANY_CALL, $line);
+            default:
+                if (null !== $alias = $this->parser->getImportedFunction($name)) {
+                    return new Twig_Node_Expression_GetAttr($alias['node'], new Twig_Node_Expression_Constant($alias['name'], $line), $args, Twig_TemplateInterface::METHOD_CALL, $line);
+                }
+
+                return new Twig_Node_Expression_Function($name, $args, $line);
+        }
+    }
+
+    public function parseSubscriptExpression($node)
+    {
+        $token = $this->parser->getStream()->next();
+        $lineno = $token->getLine();
+        $arguments = new Twig_Node();
+        $type = Twig_TemplateInterface::ANY_CALL;
+        if ($token->getValue() == '.') {
+            $token = $this->parser->getStream()->next();
+            if (
+                $token->getType() == Twig_Token::NAME_TYPE
+                ||
+                $token->getType() == Twig_Token::NUMBER_TYPE
+                ||
+                ($token->getType() == Twig_Token::OPERATOR_TYPE && preg_match(Twig_Lexer::REGEX_NAME, $token->getValue()))
+            ) {
+                $arg = new Twig_Node_Expression_Constant($token->getValue(), $lineno);
+
+                if ($this->parser->getStream()->test(Twig_Token::PUNCTUATION_TYPE, '(')) {
+                    $type = Twig_TemplateInterface::METHOD_CALL;
+                    $arguments = $this->parseArguments();
+                } else {
+                    $arguments = new Twig_Node();
+                }
+            } else {
+                throw new Twig_Error_Syntax('Expected name or number', $lineno);
+            }
+        } else {
+            $type = Twig_TemplateInterface::ARRAY_CALL;
+
+            $arg = $this->parseExpression();
+            $this->parser->getStream()->expect(Twig_Token::PUNCTUATION_TYPE, ']');
+        }
+
+        return new Twig_Node_Expression_GetAttr($node, $arg, $arguments, $type, $lineno);
+    }
+
+    public function parseFilterExpression($node)
+    {
+        $this->parser->getStream()->next();
+
+        return $this->parseFilterExpressionRaw($node);
+    }
+
+    public function parseFilterExpressionRaw($node, $tag = null)
+    {
+        while (true) {
+            $token = $this->parser->getStream()->expect(Twig_Token::NAME_TYPE);
+
+            $name = new Twig_Node_Expression_Constant($token->getValue(), $token->getLine());
+            if (!$this->parser->getStream()->test(Twig_Token::PUNCTUATION_TYPE, '(')) {
+                $arguments = new Twig_Node();
+            } else {
+                $arguments = $this->parseArguments();
+            }
+
+            $node = new Twig_Node_Expression_Filter($node, $name, $arguments, $token->getLine(), $tag);
+
+            if (!$this->parser->getStream()->test(Twig_Token::PUNCTUATION_TYPE, '|')) {
+                break;
+            }
+
+            $this->parser->getStream()->next();
+        }
+
+        return $node;
+    }
+
+    public function parseArguments()
+    {
+        $args = array();
+        $stream = $this->parser->getStream();
+
+        $stream->expect(Twig_Token::PUNCTUATION_TYPE, '(', 'A list of arguments must be opened by a parenthesis');
+        while (!$stream->test(Twig_Token::PUNCTUATION_TYPE, ')')) {
+            if (!empty($args)) {
+                $stream->expect(Twig_Token::PUNCTUATION_TYPE, ',', 'Arguments must be separated by a comma');
+            }
+            $args[] = $this->parseExpression();
+        }
+        $stream->expect(Twig_Token::PUNCTUATION_TYPE, ')', 'A list of arguments must be closed by a parenthesis');
+
+        return new Twig_Node($args);
+    }
+
+    public function parseAssignmentExpression()
+    {
+        $targets = array();
+        while (true) {
+            $token = $this->parser->getStream()->expect(Twig_Token::NAME_TYPE, null, 'Only variables can be assigned to');
+            if (in_array($token->getValue(), array('true', 'false', 'none'))) {
+                throw new Twig_Error_Syntax(sprintf('You cannot assign a value to "%s"', $token->getValue()), $token->getLine());
+            }
+            $targets[] = new Twig_Node_Expression_AssignName($token->getValue(), $token->getLine());
+
+            if (!$this->parser->getStream()->test(Twig_Token::PUNCTUATION_TYPE, ',')) {
+                break;
+            }
+            $this->parser->getStream()->next();
+        }
+
+        return new Twig_Node($targets);
+    }
+
+    public function parseMultitargetExpression()
+    {
+        $targets = array();
+        while (true) {
+            $targets[] = $this->parseExpression();
+            if (!$this->parser->getStream()->test(Twig_Token::PUNCTUATION_TYPE, ',')) {
+                break;
+            }
+            $this->parser->getStream()->next();
+        }
+
+        return new Twig_Node($targets);
+    }
+}