switched to namespace first, PSR-0 as a fallback

src/TokenStream.php

@@ -1,11 +1,150 @@
 <?php
 
+/*
+ * This file is part of Twig.
+ *
+ * (c) Fabien Potencier
+ * (c) Armin Ronacher
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
 namespace Twig;
 
-class_exists('Twig_TokenStream');
+use Twig\Error\SyntaxError;
 
-if (\false) {
-    class TokenStream extends \Twig_TokenStream
+/**
+ * Represents a token stream.
+ *
+ * @author Fabien Potencier <fabien@symfony.com>
+ */
+final class TokenStream
+{
+    private $tokens;
+    private $current = 0;
+    private $source;
+
+    public function __construct(array $tokens, Source $source = null)
     {
+        $this->tokens = $tokens;
+        $this->source = $source ?: new Source('', '');
+    }
+
+    public function __toString()
+    {
+        return implode("\n", $this->tokens);
+    }
+
+    public function injectTokens(array $tokens)
+    {
+        $this->tokens = array_merge(\array_slice($this->tokens, 0, $this->current), $tokens, \array_slice($this->tokens, $this->current));
+    }
+
+    /**
+     * Sets the pointer to the next token and returns the old one.
+     *
+     * @return Token
+     */
+    public function next()
+    {
+        if (!isset($this->tokens[++$this->current])) {
+            throw new SyntaxError('Unexpected end of template.', $this->tokens[$this->current - 1]->getLine(), $this->source);
+        }
+
+        return $this->tokens[$this->current - 1];
+    }
+
+    /**
+     * Tests a token, sets the pointer to the next one and returns it or throws a syntax error.
+     *
+     * @return Token|null The next token if the condition is true, null otherwise
+     */
+    public function nextIf($primary, $secondary = null)
+    {
+        if ($this->tokens[$this->current]->test($primary, $secondary)) {
+            return $this->next();
+        }
+    }
+
+    /**
+     * Tests a token and returns it or throws a syntax error.
+     *
+     * @return Token
+     */
+    public function expect($type, $value = null, $message = null)
+    {
+        $token = $this->tokens[$this->current];
+        if (!$token->test($type, $value)) {
+            $line = $token->getLine();
+            throw new SyntaxError(sprintf('%sUnexpected token "%s" of value "%s" ("%s" expected%s).',
+                $message ? $message.'. ' : '',
+                Token::typeToEnglish($token->getType()), $token->getValue(),
+                Token::typeToEnglish($type), $value ? sprintf(' with value "%s"', $value) : ''),
+                $line,
+                $this->source
+            );
+        }
+        $this->next();
+
+        return $token;
+    }
+
+    /**
+     * Looks at the next token.
+     *
+     * @param int $number
+     *
+     * @return Token
+     */
+    public function look($number = 1)
+    {
+        if (!isset($this->tokens[$this->current + $number])) {
+            throw new SyntaxError('Unexpected end of template.', $this->tokens[$this->current + $number - 1]->getLine(), $this->source);
+        }
+
+        return $this->tokens[$this->current + $number];
+    }
+
+    /**
+     * Tests the current token.
+     *
+     * @return bool
+     */
+    public function test($primary, $secondary = null)
+    {
+        return $this->tokens[$this->current]->test($primary, $secondary);
+    }
+
+    /**
+     * Checks if end of stream was reached.
+     *
+     * @return bool
+     */
+    public function isEOF()
+    {
+        return /* Token::EOF_TYPE */ -1 === $this->tokens[$this->current]->getType();
+    }
+
+    /**
+     * @return Token
+     */
+    public function getCurrent()
+    {
+        return $this->tokens[$this->current];
+    }
+
+    /**
+     * Gets the source associated with this stream.
+     *
+     * @return Source
+     *
+     * @internal
+     */
+    public function getSourceContext()
+    {
+        return $this->source;
     }
 }
+
+class_alias('Twig\TokenStream', 'Twig_TokenStream');