1<?php
2
3/*
4 * This file is part of Twig.
5 *
6 * (c) Fabien Potencier
7 * (c) Armin Ronacher
8 *
9 * For the full copyright and license information, please view the LICENSE
10 * file that was distributed with this source code.
11 */
12
13namespace Twig;
14
15use Twig\Error\SyntaxError;
16
17/**
18 * Represents a token stream.
19 *
20 * @author Fabien Potencier <fabien@symfony.com>
21 */
22final class TokenStream
23{
24    private $tokens;
25    private $current = 0;
26    private $source;
27
28    public function __construct(array $tokens, Source $source = null)
29    {
30        $this->tokens = $tokens;
31        $this->source = $source ?: new Source('', '');
32    }
33
34    public function __toString()
35    {
36        return implode("\n", $this->tokens);
37    }
38
39    public function injectTokens(array $tokens)
40    {
41        $this->tokens = array_merge(\array_slice($this->tokens, 0, $this->current), $tokens, \array_slice($this->tokens, $this->current));
42    }
43
44    /**
45     * Sets the pointer to the next token and returns the old one.
46     */
47    public function next(): Token
48    {
49        if (!isset($this->tokens[++$this->current])) {
50            throw new SyntaxError('Unexpected end of template.', $this->tokens[$this->current - 1]->getLine(), $this->source);
51        }
52
53        return $this->tokens[$this->current - 1];
54    }
55
56    /**
57     * Tests a token, sets the pointer to the next one and returns it or throws a syntax error.
58     *
59     * @return Token|null The next token if the condition is true, null otherwise
60     */
61    public function nextIf($primary, $secondary = null)
62    {
63        if ($this->tokens[$this->current]->test($primary, $secondary)) {
64            return $this->next();
65        }
66    }
67
68    /**
69     * Tests a token and returns it or throws a syntax error.
70     */
71    public function expect($type, $value = null, string $message = null): Token
72    {
73        $token = $this->tokens[$this->current];
74        if (!$token->test($type, $value)) {
75            $line = $token->getLine();
76            throw new SyntaxError(sprintf('%sUnexpected token "%s"%s ("%s" expected%s).',
77                $message ? $message.'. ' : '',
78                Token::typeToEnglish($token->getType()),
79                $token->getValue() ? sprintf(' of value "%s"', $token->getValue()) : '',
80                Token::typeToEnglish($type), $value ? sprintf(' with value "%s"', $value) : ''),
81                $line,
82                $this->source
83            );
84        }
85        $this->next();
86
87        return $token;
88    }
89
90    /**
91     * Looks at the next token.
92     */
93    public function look(int $number = 1): Token
94    {
95        if (!isset($this->tokens[$this->current + $number])) {
96            throw new SyntaxError('Unexpected end of template.', $this->tokens[$this->current + $number - 1]->getLine(), $this->source);
97        }
98
99        return $this->tokens[$this->current + $number];
100    }
101
102    /**
103     * Tests the current token.
104     */
105    public function test($primary, $secondary = null): bool
106    {
107        return $this->tokens[$this->current]->test($primary, $secondary);
108    }
109
110    /**
111     * Checks if end of stream was reached.
112     */
113    public function isEOF(): bool
114    {
115        return /* Token::EOF_TYPE */ -1 === $this->tokens[$this->current]->getType();
116    }
117
118    public function getCurrent(): Token
119    {
120        return $this->tokens[$this->current];
121    }
122
123    /**
124     * Gets the source associated with this stream.
125     *
126     * @internal
127     */
128    public function getSourceContext(): Source
129    {
130        return $this->source;
131    }
132}
133
134class_alias('Twig\TokenStream', 'Twig_TokenStream');
135