mirror of
https://github.com/retailcrm/graphql-php.git
synced 2025-02-11 10:09:24 +03:00
Refactored Lexer algorithm for better performance. Now O(N) vs O(N^2) previously (#137)
This commit is contained in:
Vladimir Razuvaev
parent
ffc4542cd0
commit
a0657b7847
@ -10,6 +10,8 @@ use GraphQL\Utils;
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* source lexes, the final Token emitted by the lexer will be of kind
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* EOF, after which the lexer will repeatedly return the same EOF token
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* whenever called.
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*
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* Algorithm is O(N) both on memory and time
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*/
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class Lexer
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{
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@ -51,6 +53,26 @@ class Lexer
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*/
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public $lineStart;
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/**
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* Current cursor position for UTF8 encoding of the source
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*
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* @var int
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*/
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private $position;
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/**
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* Current cursor position for ASCII representation of the source
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*
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* @var int
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*/
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private $byteStreamPosition;
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/**
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* Lexer constructor.
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*
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* @param Source $source
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* @param array $options
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*/
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public function __construct(Source $source, array $options = [])
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{
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$startOfFileToken = new Token(Token::SOF, 0, 0, 0, 0, null);
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@ -61,6 +83,7 @@ class Lexer
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$this->token = $startOfFileToken;
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$this->line = 1;
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$this->lineStart = 0;
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$this->position = $this->byteStreamPosition = 0;
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}
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/**
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@ -95,10 +118,11 @@ class Lexer
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*/
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private function readToken(Token $prev)
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{
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$body = $this->source->body;
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$bodyLength = $this->source->length;
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$position = $this->positionAfterWhitespace($prev->end);
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$this->positionAfterWhitespace();
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$position = $this->position;
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$line = $this->line;
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$col = 1 + $position - $this->lineStart;
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@ -106,7 +130,8 @@ class Lexer
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return new Token(Token::EOF, $bodyLength, $bodyLength, $line, $col, $prev);
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}
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$code = Utils::charCodeAt($body, $position);
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// Read next char and advance string cursor:
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list (, $code, $bytes) = $this->readChar(true);
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// SourceCharacter
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if ($code < 0x0020 && $code !== 0x0009 && $code !== 0x000A && $code !== 0x000D) {
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@ -121,7 +146,8 @@ class Lexer
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case 33: // !
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return new Token(Token::BANG, $position, $position + 1, $line, $col, $prev);
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case 35: // #
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return $this->readComment($position, $line, $col, $prev);
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$this->moveStringCursor(-1, -1 * $bytes);
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return $this->readComment($line, $col, $prev);
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case 36: // $
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return new Token(Token::DOLLAR, $position, $position + 1, $line, $col, $prev);
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case 40: // (
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@ -129,8 +155,10 @@ class Lexer
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case 41: // )
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return new Token(Token::PAREN_R, $position, $position + 1, $line, $col, $prev);
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case 46: // .
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if (Utils::charCodeAt($body, $position+1) === 46 &&
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Utils::charCodeAt($body, $position+2) === 46) {
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list (, $charCode1) = $this->readChar(true);
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list (, $charCode2) = $this->readChar(true);
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if ($charCode1 === 46 && $charCode2 === 46) {
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return new Token(Token::SPREAD, $position, $position + 3, $line, $col, $prev);
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}
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break;
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@ -162,21 +190,24 @@ class Lexer
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case 105: case 106: case 107: case 108: case 109: case 110: case 111:
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case 112: case 113: case 114: case 115: case 116: case 117: case 118:
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case 119: case 120: case 121: case 122:
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return $this->readName($position, $line, $col, $prev);
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return $this->moveStringCursor(-1, -1 * $bytes)
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->readName($line, $col, $prev);
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// -
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case 45:
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// 0-9
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case 48: case 49: case 50: case 51: case 52:
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case 53: case 54: case 55: case 56: case 57:
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return $this->readNumber($position, $code, $line, $col, $prev);
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return $this->moveStringCursor(-1, -1 * $bytes)
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->readNumber($line, $col, $prev);
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// "
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case 34:
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return $this->readString($position, $line, $col, $prev);
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return $this->moveStringCursor(-1, -1 * $bytes)
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->readString($line, $col, $prev);
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}
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$errMessage = $code === 39
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? "Unexpected single quote character ('), did you mean to use ". 'a double quote (")?'
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: 'Cannot parse the unexpected character ' . Utils::printCharCode($code) . '.';
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? "Unexpected single quote character ('), did you mean to use ". 'a double quote (")?'
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: 'Cannot parse the unexpected character ' . Utils::printCharCode($code) . '.';
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throw new SyntaxError(
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$this->source,
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@ -190,38 +221,34 @@ class Lexer
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*
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* [_A-Za-z][_0-9A-Za-z]*
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*
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* @param int $position
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* @param int $line
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* @param int $col
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* @param Token $prev
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* @return Token
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*/
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private function readName($position, $line, $col, Token $prev)
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private function readName($line, $col, Token $prev)
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{
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$body = $this->source->body;
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$bodyLength = $this->source->length;
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$end = $position + 1;
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$value = '';
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$start = $this->position;
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list ($char, $code) = $this->readChar();
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while (
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$end !== $bodyLength &&
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($code = Utils::charCodeAt($body, $end)) &&
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(
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$code === 95 || // _
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$code >= 48 && $code <= 57 || // 0-9
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$code >= 65 && $code <= 90 || // A-Z
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$code >= 97 && $code <= 122 // a-z
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)
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) {
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++$end;
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while ($code && (
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$code === 95 || // _
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$code >= 48 && $code <= 57 || // 0-9
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$code >= 65 && $code <= 90 || // A-Z
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$code >= 97 && $code <= 122 // a-z
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)) {
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$value .= $char;
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list ($char, $code) = $this->moveStringCursor(1, 1)->readChar();
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}
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return new Token(
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Token::NAME,
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$position,
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$end,
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$start,
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$this->position,
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$line,
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$col,
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$prev,
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mb_substr($body, $position, $end - $position, 'UTF-8')
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$value
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);
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}
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@ -232,126 +259,130 @@ class Lexer
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* Int: -?(0|[1-9][0-9]*)
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* Float: -?(0|[1-9][0-9]*)(\.[0-9]+)?((E|e)(+|-)?[0-9]+)?
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*
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* @param int $start
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* @param string $firstCode
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* @param int $line
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* @param int $col
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* @param Token $prev
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* @return Token
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* @throws SyntaxError
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*/
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private function readNumber($start, $firstCode, $line, $col, Token $prev)
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private function readNumber($line, $col, Token $prev)
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{
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$code = $firstCode;
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$body = $this->source->body;
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$position = $start;
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$value = '';
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$start = $this->position;
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list ($char, $code) = $this->readChar();
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$isFloat = false;
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if ($code === 45) { // -
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$code = Utils::charCodeAt($body, ++$position);
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$value .= $char;
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list ($char, $code) = $this->moveStringCursor(1, 1)->readChar();
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}
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// guard against leading zero's
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if ($code === 48) { // 0
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$code = Utils::charCodeAt($body, ++$position);
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$value .= $char;
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list ($char, $code) = $this->moveStringCursor(1, 1)->readChar();
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if ($code >= 48 && $code <= 57) {
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throw new SyntaxError($this->source, $position, "Invalid number, unexpected digit after 0: " . Utils::printCharCode($code));
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throw new SyntaxError($this->source, $this->position, "Invalid number, unexpected digit after 0: " . Utils::printCharCode($code));
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}
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} else {
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$position = $this->readDigits($position, $code);
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$code = Utils::charCodeAt($body, $position);
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$value .= $this->readDigits();
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list ($char, $code) = $this->readChar();
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}
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if ($code === 46) { // .
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$isFloat = true;
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$this->moveStringCursor(1, 1);
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$code = Utils::charCodeAt($body, ++$position);
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$position = $this->readDigits($position, $code);
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$code = Utils::charCodeAt($body, $position);
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$value .= $char;
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$value .= $this->readDigits();
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list ($char, $code) = $this->readChar();
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}
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if ($code === 69 || $code === 101) { // E e
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$isFloat = true;
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$code = Utils::charCodeAt($body, ++$position);
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$value .= $char;
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list ($char, $code) = $this->moveStringCursor(1, 1)->readChar();
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if ($code === 43 || $code === 45) { // + -
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$code = Utils::charCodeAt($body, ++$position);
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$value .= $char;
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$this->moveStringCursor(1, 1);
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}
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$position = $this->readDigits($position, $code);
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$value .= $this->readDigits();
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}
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return new Token(
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$isFloat ? Token::FLOAT : Token::INT,
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$start,
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$position,
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$this->position,
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$line,
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$col,
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$prev,
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mb_substr($body, $start, $position - $start, 'UTF-8')
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$value
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);
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}
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/**
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* Returns the new position in the source after reading digits.
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* Returns string with all digits + changes current string cursor position to point to the first char after digits
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*/
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private function readDigits($start, $firstCode)
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private function readDigits()
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{
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$body = $this->source->body;
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$position = $start;
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$code = $firstCode;
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list ($char, $code) = $this->readChar();
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if ($code >= 48 && $code <= 57) { // 0 - 9
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$value = '';
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do {
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$code = Utils::charCodeAt($body, ++$position);
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$value .= $char;
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list ($char, $code) = $this->moveStringCursor(1, 1)->readChar();
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} while ($code >= 48 && $code <= 57); // 0 - 9
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return $position;
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return $value;
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}
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if ($position > $this->source->length - 1) {
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if ($this->position > $this->source->length - 1) {
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$code = null;
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}
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throw new SyntaxError(
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$this->source,
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$position,
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$this->position,
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'Invalid number, expected digit but got: ' . Utils::printCharCode($code)
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);
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}
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/**
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* @param int $start
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* @param int $line
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* @param int $col
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* @param Token $prev
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* @return Token
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* @throws SyntaxError
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*/
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private function readString($start, $line, $col, Token $prev)
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private function readString($line, $col, Token $prev)
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{
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$body = $this->source->body;
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$bodyLength = $this->source->length;
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$start = $this->position;
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$position = $start + 1;
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$chunkStart = $position;
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$code = null;
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// Skip leading quote and read first string char:
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list ($char, $code, $bytes) = $this->moveStringCursor(1, 1)->readChar();
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$chunk = '';
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$value = '';
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while (
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$position < $bodyLength &&
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($code = Utils::charCodeAt($body, $position)) &&
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$code &&
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// not LineTerminator
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$code !== 0x000A && $code !== 0x000D &&
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$code !== 10 && $code !== 13 &&
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// not Quote (")
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$code !== 34
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) {
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$this->assertValidStringCharacterCode($code, $position);
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$this->assertValidStringCharacterCode($code, $this->position);
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$this->moveStringCursor(1, $bytes);
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++$position;
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if ($code === 92) { // \
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$value .= mb_substr($body, $chunkStart, $position - 1 - $chunkStart, 'UTF-8');
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$code = Utils::charCodeAt($body, $position);
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$value .= $chunk;
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list (, $code) = $this->readChar(true);
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switch ($code) {
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case 34: $value .= '"'; break;
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case 47: $value .= '/'; break;
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@ -362,45 +393,51 @@ class Lexer
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case 114: $value .= "\r"; break;
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case 116: $value .= "\t"; break;
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case 117:
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$hex = mb_substr($body, $position + 1, 4, 'UTF-8');
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$position = $this->position;
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list ($hex) = $this->readChars(4, true);
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if (!preg_match('/[0-9a-fA-F]{4}/', $hex)) {
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throw new SyntaxError(
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$this->source,
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$position,
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$position - 1,
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'Invalid character escape sequence: \\u' . $hex
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);
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}
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$code = hexdec($hex);
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$this->assertValidStringCharacterCode($code, $position - 1);
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$this->assertValidStringCharacterCode($code, $position - 2);
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$value .= Utils::chr($code);
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$position += 4;
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break;
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default:
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throw new SyntaxError(
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$this->source,
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$position,
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$this->position - 1,
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'Invalid character escape sequence: \\' . Utils::chr($code)
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);
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}
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++$position;
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$chunkStart = $position;
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$chunk = '';
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} else {
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$chunk .= $char;
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}
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list ($char, $code, $bytes) = $this->readChar();
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}
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if ($code !== 34) {
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throw new SyntaxError(
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$this->source,
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$position,
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$this->position,
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'Unterminated string.'
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);
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}
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$value .= mb_substr($body, $chunkStart, $position - $chunkStart, 'UTF-8');
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$value .= $chunk;
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// Skip trailing quote:
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$this->moveStringCursor(1, 1);
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return new Token(
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Token::STRING,
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$start,
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$position + 1,
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$this->position,
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$line,
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$col,
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$prev,
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@ -422,43 +459,33 @@ class Lexer
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/**
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* Reads from body starting at startPosition until it finds a non-whitespace
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* or commented character, then returns the position of that character for
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* lexing.
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*
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* @param $startPosition
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* @return int
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* or commented character, then places cursor to the position of that character.
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*/
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private function positionAfterWhitespace($startPosition)
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private function positionAfterWhitespace()
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{
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$body = $this->source->body;
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$bodyLength = $this->source->length;
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$position = $startPosition;
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while ($position < $bodyLength) {
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$code = Utils::charCodeAt($body, $position);
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while ($this->position < $this->source->length) {
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list(, $code, $bytes) = $this->readChar();
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// Skip whitespace
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// tab | space | comma | BOM
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if ($code === 9 || $code === 32 || $code === 44 || $code === 0xFEFF) {
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$position++;
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$this->moveStringCursor(1, $bytes);
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} else if ($code === 10) { // new line
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$position++;
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$this->moveStringCursor(1, $bytes);
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$this->line++;
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$this->lineStart = $position;
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$this->lineStart = $this->position;
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} else if ($code === 13) { // carriage return
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if (Utils::charCodeAt($body, $position + 1) === 10) {
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$position += 2;
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} else {
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$position ++;
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list(, $nextCode, $nextBytes) = $this->moveStringCursor(1, $bytes)->readChar();
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if ($nextCode === 10) { // lf after cr
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$this->moveStringCursor(1, $nextBytes);
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}
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$this->line++;
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$this->lineStart = $position;
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$this->lineStart = $this->position;
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} else {
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break;
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}
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}
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return $position;
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}
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/**
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@ -466,21 +493,22 @@ class Lexer
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*
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* #[\u0009\u0020-\uFFFF]*
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*
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* @param $start
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* @param $line
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* @param $col
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* @param Token $prev
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* @return Token
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*/
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private function readComment($start, $line, $col, Token $prev)
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private function readComment($line, $col, Token $prev)
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{
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$body = $this->source->body;
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$position = $start;
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$start = $this->position;
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$value = '';
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$bytes = 1;
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|
||||
do {
|
||||
$code = Utils::charCodeAt($body, ++$position);
|
||||
list ($char, $code, $bytes) = $this->moveStringCursor(1, $bytes)->readChar();
|
||||
$value .= $char;
|
||||
} while (
|
||||
$code !== null &&
|
||||
$code &&
|
||||
// SourceCharacter but not LineTerminator
|
||||
($code > 0x001F || $code === 0x0009)
|
||||
);
|
||||
@ -488,11 +516,97 @@ class Lexer
|
||||
return new Token(
|
||||
Token::COMMENT,
|
||||
$start,
|
||||
$position,
|
||||
$this->position,
|
||||
$line,
|
||||
$col,
|
||||
$prev,
|
||||
mb_substr($body, $start + 1, $position - $start, 'UTF-8')
|
||||
$value
|
||||
);
|
||||
}
|
||||
|
||||
/**
|
||||
* Reads next UTF8Character from the byte stream, starting from $byteStreamPosition.
|
||||
*
|
||||
* @param bool $advance
|
||||
* @param int $byteStreamPosition
|
||||
* @return array
|
||||
*/
|
||||
private function readChar($advance = false, $byteStreamPosition = null)
|
||||
{
|
||||
if ($byteStreamPosition === null) {
|
||||
$byteStreamPosition = $this->byteStreamPosition;
|
||||
}
|
||||
|
||||
$code = 0;
|
||||
$utf8char = '';
|
||||
$bytes = 0;
|
||||
$positionOffset = 0;
|
||||
|
||||
if (isset($this->source->body[$byteStreamPosition])) {
|
||||
$ord = ord($this->source->body[$byteStreamPosition]);
|
||||
|
||||
if ($ord < 128) {
|
||||
$bytes = 1;
|
||||
} else if ($ord < 224) {
|
||||
$bytes = 2;
|
||||
} elseif ($ord < 240) {
|
||||
$bytes = 3;
|
||||
} else {
|
||||
$bytes = 4;
|
||||
}
|
||||
|
||||
$utf8char = '';
|
||||
for ($pos = $byteStreamPosition; $pos < $byteStreamPosition + $bytes; $pos++) {
|
||||
$utf8char .= $this->source->body[$pos];
|
||||
}
|
||||
$positionOffset = 1;
|
||||
$code = $bytes === 1 ? $ord : Utils::ord($utf8char);
|
||||
}
|
||||
|
||||
if ($advance) {
|
||||
$this->moveStringCursor($positionOffset, $bytes);
|
||||
}
|
||||
|
||||
return [$utf8char, $code, $bytes];
|
||||
}
|
||||
|
||||
/**
|
||||
* Reads next $numberOfChars UTF8 characters from the byte stream, starting from $byteStreamPosition.
|
||||
*
|
||||
* @param $numberOfChars
|
||||
* @param bool $advance
|
||||
* @param null $byteStreamPosition
|
||||
* @return array
|
||||
*/
|
||||
private function readChars($numberOfChars, $advance = false, $byteStreamPosition = null)
|
||||
{
|
||||
$result = '';
|
||||
$totalBytes = 0;
|
||||
$byteOffset = $byteStreamPosition ?: $this->byteStreamPosition;
|
||||
|
||||
for ($i = 0; $i < $numberOfChars; $i++) {
|
||||
list ($char, $code, $bytes) = $this->readChar(false, $byteOffset);
|
||||
$totalBytes += $bytes;
|
||||
$byteOffset += $bytes;
|
||||
$result .= $char;
|
||||
}
|
||||
if ($advance) {
|
||||
$this->moveStringCursor($numberOfChars, $totalBytes);
|
||||
}
|
||||
return [$result, $totalBytes];
|
||||
}
|
||||
|
||||
/**
|
||||
* Moves internal string cursor position
|
||||
*
|
||||
* @param $positionOffset
|
||||
* @param $byteStreamOffset
|
||||
* @return $this
|
||||
*/
|
||||
private function moveStringCursor($positionOffset, $byteStreamOffset)
|
||||
{
|
||||
$this->position += $positionOffset;
|
||||
$this->byteStreamPosition += $byteStreamOffset;
|
||||
return $this;
|
||||
}
|
||||
}
|
||||
|
||||
@ -290,15 +290,17 @@ class Utils
|
||||
*/
|
||||
public static function ord($char, $encoding = 'UTF-8')
|
||||
{
|
||||
if (!$char && '0' !== $char) {
|
||||
return 0;
|
||||
}
|
||||
if (!isset($char[1])) {
|
||||
return ord($char);
|
||||
}
|
||||
if ($encoding === 'UCS-4BE') {
|
||||
list(, $ord) = (strlen($char) === 4) ? unpack('N', $char) : unpack('n', $char);
|
||||
return $ord;
|
||||
} else {
|
||||
return self::ord(mb_convert_encoding($char, 'UCS-4BE', $encoding), 'UCS-4BE');
|
||||
if ($encoding !== 'UCS-4BE') {
|
||||
$char = mb_convert_encoding($char, 'UCS-4BE', $encoding);
|
||||
}
|
||||
list(, $ord) = unpack('N', $char);
|
||||
return $ord;
|
||||
}
|
||||
|
||||
/**
|
||||
|
||||
Loading…
x
Reference in New Issue
Block a user