Matthias Andreas Benkard | 12a5735 | 2021-12-28 18:02:04 +0100 | [diff] [blame^] | 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 | |
| 13 | namespace Twig; |
| 14 | |
| 15 | use Twig\Error\SyntaxError; |
| 16 | |
| 17 | /** |
| 18 | * Represents a token stream. |
| 19 | * |
| 20 | * @author Fabien Potencier <fabien@symfony.com> |
| 21 | */ |
| 22 | final 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 | } |