Lexer::readToken() - Code Metrics - Inspection of "Lexer optimizations" - digiaonline/graphql-php - Measure and Improve Code Quality continuously with Scrutinizer

Passed

Pull Request — master (#196)

by Christoffer

created 2018-04-10 09:36 UTC

Lexer::readToken() C

↳ Parent: Lexer

Complexity

Conditions	24
Paths	9

Size

Total Lines	53
Code Lines	23

Duplication

Lines	0
Ratio	0 %

Importance

Changes

Metric	Value
dl	0
loc	53
rs	6.1349
c	0
b	0
f	0
cc	24
eloc	23
nc	9
nop	1

How to fix Long Method Complexity

<?php

namespace Digia\GraphQL\Language;

use Digia\GraphQL\Error\SyntaxErrorException;

class Lexer implements LexerInterface
{
    protected const ENCODING = 'UTF-8';

    /**
     * A map between punctuation character code and the corresponding token kind.
     *
     * @var array
     */
    protected static $codeTokenKindMap = [
        33  => TokenKindEnum::BANG,
        36  => TokenKindEnum::DOLLAR,
        38  => TokenKindEnum::AMP,
        40  => TokenKindEnum::PAREN_L,
        41  => TokenKindEnum::PAREN_R,
        58  => TokenKindEnum::COLON,
        61  => TokenKindEnum::EQUALS,
        64  => TokenKindEnum::AT,
        91  => TokenKindEnum::BRACKET_L,
        93  => TokenKindEnum::BRACKET_R,
        123 => TokenKindEnum::BRACE_L,
        124 => TokenKindEnum::PIPE,
        125 => TokenKindEnum::BRACE_R,
    ];

    /**
     * The source file for this lexer.
     *
     * @var Source
     */
    protected $source;

    /**
     * The contents of the source file.
     *
     * @var string
     */
    protected $body;

    /**
     * The total number of characters in the source file.
     *
     * @var int
     */
    protected $bodyLength;

    /**
     * The options for this lexer.
     *
     * @var array
     */
    protected $options = [];

    /**
     * The previously focused non-ignored token.
     *
     * @var Token
     */
    protected $lastToken;

    /**
     * The currently focused non-ignored token.
     *
     * @var Token
     */
    protected $token;

    /**
     * The current position.
     *
     * @var int
     */
    protected $pos;

    /**
     * The (1-indexed) line containing the current token.
     *
     * @var int
     */
    protected $line;

    /**
     * The character offset at which the current line begins.
     *
     * @var int
     */
    protected $lineStart;

    /**
     * @var array
     */
    protected static $charCodeCache = [];

    /**
     * Lexer constructor.
     * @param Source|null $source
     * @param array       $options
     */
    public function __construct(Source $source, array $options)
    {
        $startOfFileToken = $this->createStartOfFileToken();

        $this->lastToken  = $startOfFileToken;
        $this->token      = $startOfFileToken;
        $this->line       = 1;
        $this->lineStart  = 0;
        $this->body       = $source->getBody();
        $this->bodyLength = \strlen($this->body);
        $this->source     = $source;
        $this->options    = $options;
    }

    /**
     * @inheritdoc
     * @throws SyntaxErrorException
     */
    public function advance(): Token
    {
        $this->lastToken = $this->token;
        return $this->token = $this->lookahead();
    }

    /**
     * @inheritdoc
     * @throws SyntaxErrorException
     */
    public function lookahead(): Token
    {
        $token = $this->token;

        if (TokenKindEnum::EOF !== $token->getKind()) {
            do {
                $next = $this->readToken($token);
                $token->setNext($next);
                $token = $next;
            } while (TokenKindEnum::COMMENT === $token->getKind());
        }

        return $token;
    }

    /**
     * @inheritdoc
     */
    public function getOption(string $name, $default = null)
    {
        return $this->options[$name] ?? $default;
    }

    /**
     * @inheritdoc
     */
    public function getTokenKind(): string
    {
        return $this->token->getKind();
    }

    /**
     * @inheritdoc
     */
    public function getTokenValue(): ?string
    {
        return $this->token->getValue();
    }

    /**
     * @inheritdoc
     */
    public function getToken(): Token
    {
        return $this->token;
    }

    /**
     * @inheritdoc
     */
    public function getSource(): Source
    {
        return $this->source;
    }

    /**
     * @inheritdoc
     */
    public function getLastToken(): Token
    {
        return $this->lastToken;
    }

    /**
     * Reads the token after the given token.
     *
     * @param Token $prev
     * @return Token
     * @throws SyntaxErrorException
     */
    protected function readToken(Token $prev): Token
    {
        $this->pos = $prev->getEnd();

        $this->skipWhitespace();

        $line = $this->line;
        $col  = (1 + $this->pos) - $this->lineStart;

        if ($this->pos >= $this->bodyLength) {
            return $this->createEndOfFileToken($line, $col, $prev);
        }

        $code = $this->readCharCode($this->pos);

        // Punctuation: [!$&:=@|()\[\]{}]{1}
        if (33 === $code || 36 === $code || 38 === $code || 58 === $code || 61 === $code || 64 === $code || 124 === $code ||
            40 === $code || 41 === $code || 91 === $code || 93 === $code || 123 === $code || 125 === $code) {
            return $this->lexPunctuation($code, $line, $col, $prev);
        }

        // Comment: #[\u0009\u0020-\uFFFF]*
        if (35 === $code) {
            return $this->lexComment($line, $col, $prev);
        }

        // Int:   -?(0|[1-9][0-9]*)
        // Float: -?(0|[1-9][0-9]*)(\.[0-9]+)?((E|e)(+|-)?[0-9]+)?
        if (45 === $code || isNumber($code)) {
            return $this->lexNumber($code, $line, $col, $prev);
        }

        // Name: [_A-Za-z][_0-9A-Za-z]*
        if (isAlphaNumeric($code)) {
            return $this->lexName($line, $col, $prev);
        }

        // Spread: ...
        if ($this->bodyLength >= 3 && $this->isSpread($code)) {
            return $this->lexSpread($line, $col, $prev);
        }

        // String: "([^"\\\u000A\u000D]|(\\(u[0-9a-fA-F]{4}|["\\/bfnrt])))*"
        if ($this->isString($code)) {
            return $this->lexString($line, $col, $prev);
        }

        // Block String: """("?"?(\\"""|\\(?!=""")|[^"\\]))*"""
        if ($this->bodyLength >= 3 && $this->isTripleQuote($code)) {
            return $this->lexBlockString($line, $col, $prev);
        }

        throw $this->createSyntaxErrorException();
    }

    /**
     * @return Token
     */
    protected function createStartOfFileToken(): Token
    {
        return new Token(TokenKindEnum::SOF);
    }

    /**
     * Creates an End Of File (EOF) token.
     *
     * @param int   $line
     * @param int   $col
     * @param Token $prev
     * @return Token
     */
    protected function createEndOfFileToken(int $line, int $col, Token $prev): Token
    {
        return new Token(TokenKindEnum::EOF, $this->bodyLength, $this->bodyLength, $line, $col, $prev);
    }

    /**
     * Reads a punctuation token from the source file.
     *
     * @param int   $code
     * @param int   $line
     * @param int   $col
     * @param Token $prev
     * @return Token
     * @throws SyntaxErrorException
     */
    protected function lexPunctuation(int $code, int $line, int $col, Token $prev): ?Token
    {
        if (!isset(self::$codeTokenKindMap[$code])) {
            throw $this->createSyntaxErrorException();
        }

        return new Token(self::$codeTokenKindMap[$code], $this->pos, $this->pos + 1, $line, $col, $prev);
    }

    /**
     * Reads a name token from the source file.
     *
     * @param int   $line
     * @param int   $col
     * @param Token $prev
     * @return Token
     */
    protected function lexName(int $line, int $col, Token $prev): Token
    {
        $start = $this->pos;

        ++$this->pos;

        while ($this->pos !== $this->bodyLength &&
            ($code = $this->readCharCode($this->pos)) !== null &&
            isAlphaNumeric($code)) {
            ++$this->pos;
        }

        $value = sliceString($this->body, $start, $this->pos);

        return new Token(TokenKindEnum::NAME, $start, $this->pos, $line, $col, $prev, $value);
    }

    /**
     * Reads a number (int or float) token from the source file.
     *
     * @param int   $code
     * @param int   $line
     * @param int   $col
     * @param Token $prev
     * @return Token
     * @throws SyntaxErrorException
     */
    protected function lexNumber(int $code, int $line, int $col, Token $prev): Token
    {
        $start   = $this->pos;
        $isFloat = false;

        if (45 === $code) {
            // -
            $code = $this->readCharCode(++$this->pos);
        }

        if (48 === $code) {
            // 0
            $code = $this->readCharCode(++$this->pos);

            if (isNumber($code)) {
                throw $this->createSyntaxErrorException(
                    \sprintf('Invalid number, unexpected digit after 0: %s.', printCharCode($code))
                );
            }
        } else {
            $this->skipDigits($code);
            $code = $this->readCharCode($this->pos);
        }

        if (46 === $code) {
            // .
            $isFloat = true;

            $code = $this->readCharCode(++$this->pos);
            $this->skipDigits($code);
            $code = $this->readCharCode($this->pos);
        }

        if (69 === $code || 101 === $code) {
            // e or E
            $isFloat = true;

            $code = $this->readCharCode(++$this->pos);

            if (43 === $code || 45 === $code) {
                // + or -
                $code = $this->readCharCode(++$this->pos);
            }

            $this->skipDigits($code);
        }

        return new Token(
            $isFloat ? TokenKindEnum::FLOAT : TokenKindEnum::INT,
            $start,
            $this->pos,
            $line,
            $col,
            $prev,
            sliceString($this->body, $start, $this->pos)
        );
    }

    /**
     * Skips digits at the current position.
     *
     * @param int $code
     * @throws SyntaxErrorException
     */
    protected function skipDigits(int $code): void
    {
        if (isNumber($code)) {
            do {
                $code = $this->readCharCode(++$this->pos);
            } while (isNumber($code));

            return;
        }

        throw $this->createSyntaxErrorException(
            \sprintf('Invalid number, expected digit but got: %s.', printCharCode($code))
        );
    }

    /**
     * Reads a comment token from the source file.
     *
     * @param int   $line
     * @param int   $col
     * @param Token $prev
     * @return Token
     */
    protected function lexComment(int $line, int $col, Token $prev): Token
    {
        $start = $this->pos;

        do {
            $code = $this->readCharCode(++$this->pos);
        } while ($code !== null && ($code > 0x001f || 0x0009 === $code)); // SourceCharacter but not LineTerminator

        return new Token(
            TokenKindEnum::COMMENT,
            $start,
            $this->pos,
            $line,
            $col,
            $prev,
            sliceString($this->body, $start + 1, $this->pos)
        );
    }

    /**
     * Reads a spread token from the source.
     *
     * @param int   $line
     * @param int   $col
     * @param Token $prev
     * @return Token
     */
    protected function lexSpread(int $line, int $col, Token $prev): Token
    {
        return new Token(TokenKindEnum::SPREAD, $this->pos, $this->pos + 3, $line, $col, $prev);
    }

    /**
     * Reads a string token from the source.
     *
     * @param int   $line
     * @param int   $col
     * @param Token $prev
     * @return Token
     * @throws SyntaxErrorException
     */
    protected function lexString(int $line, int $col, Token $prev): Token
    {
        $start      = $this->pos;
        $chunkStart = ++$this->pos; // skip the quote
        $value      = '';

        while ($this->pos < $this->bodyLength &&
            ($code = $this->readCharCode($this->pos)) !== null && !isLineTerminator($code)) {
            // Closing Quote (")
            if (34 === $code) {
                $value .= sliceString($this->body, $chunkStart, $this->pos);
                return new Token(TokenKindEnum::STRING, $start, $this->pos + 1, $line, $col, $prev, $value);
            }

            if (isSourceCharacter($code)) {
                throw $this->createSyntaxErrorException(
                    \sprintf('Invalid character within String: %s.', printCharCode($code))
                );
            }

            ++$this->pos;

            if (92 === $code) {
                // \
                $value .= sliceString($this->body, $chunkStart, $this->pos - 1);

                $code = $this->readCharCode($this->pos);

                switch ($code) {
                    case 34: // "
                        $value .= '"';
                        break;
                    case 47: // /
                        $value .= '/';
                        break;
                    case 92: // \
                        $value .= '\\';
                        break;
                    case 98: // b
                        $value .= '\b';
                        break;
                    case 102: // f
                        $value .= '\f';
                        break;
                    case 110: // n
                        $value .= '\n';
                        break;
                    case 114: // r
                        $value .= '\r';
                        break;
                    case 116: // t
                        $value .= '\t';
                        break;
                    case 117: // u
                        $unicodeString = sliceString($this->body, $this->pos + 1, $this->pos + 5);

                        if (!\preg_match('/[0-9A-Fa-f]{4}/', $unicodeString)) {
                            throw $this->createSyntaxErrorException(
                                \sprintf('Invalid character escape sequence: \\u%s.', $unicodeString)
                            );
                        }

                        $value     .= '\\u' . $unicodeString;
                        $this->pos += 4;

                        break;
                    default:
                        throw $this->createSyntaxErrorException(
                            \sprintf('Invalid character escape sequence: \\%s.', \chr($code))
                        );
                }

                ++$this->pos;

                $chunkStart = $this->pos;
            }
        }

        throw $this->createSyntaxErrorException('Unterminated string.');
    }

    /**
     * Reads a block string token from the source file.
     *
     * @param int   $line
     * @param int   $col
     * @param Token $prev
     * @return Token
     * @throws SyntaxErrorException
     */
    protected function lexBlockString(int $line, int $col, Token $prev): Token
    {
        $start      = $this->pos;
        $this->pos  = $start + 3; // skip the triple-quote
        $chunkStart = $this->pos;
        $rawValue   = '';

        while ($this->pos < $this->bodyLength && ($code = $this->readCharCode($this->pos)) !== null) {
            // Closing Triple-Quote (""")
            if ($this->isTripleQuote($code)) {
                $rawValue .= sliceString($this->body, $chunkStart, $this->pos);
                return new Token(
                    TokenKindEnum::BLOCK_STRING,
                    $start,
                    $this->pos + 3,
                    $line,
                    $col,
                    $prev,
                    blockStringValue($rawValue)
                );
            }

            if (isSourceCharacter($code) && !isLineTerminator($code)) {
                throw $this->createSyntaxErrorException(
                    \sprintf('Invalid character within String: %s.', printCharCode($code))
                );
            }

            if ($this->isEscapedTripleQuote($code)) {
                $rawValue   .= sliceString($this->body, $chunkStart, $this->pos) . '"""';
                $this->pos  += 4;
                $chunkStart = $this->pos;
            } else {
                ++$this->pos;
            }
        }

        throw $this->createSyntaxErrorException('Unterminated string.');
    }

    /**
     * Skips whitespace at the current position.
     */
    protected function skipWhitespace(): void
    {
        while ($this->pos < $this->bodyLength) {
            $code = $this->readCharCode($this->pos);

            if (9 === $code || 32 === $code || 44 === $code || 0xfeff === $code) {
                // tab | space | comma | BOM
                ++$this->pos;
            } elseif (10 === $code) {
                // new line (\n)
                ++$this->pos;
                ++$this->line;
                $this->lineStart = $this->pos;
            } elseif (13 === $code) {
                // carriage return (\r)
                if (10 === $this->readCharCode($this->pos + 1)) {
                    // carriage return and new line (\r\n)
                    $this->pos += 2;
                } else {
                    ++$this->pos;
                }
                ++$this->line;
                $this->lineStart = $this->pos;
            } else {
                break;
            }
        }
    }

    /**
     * @param int $pos
     * @return int
     */
    protected function readCharCode(int $pos): int
    {
        $char = \mb_substr($this->body, $pos, 1, self::ENCODING);

        if ('' === $char) {
            return 0;
        }

        if (!isset(self::$charCodeCache[$char])) {
            self::$charCodeCache[$char] = \mb_ord($char, self::ENCODING);
        }

        return self::$charCodeCache[$char];
    }

    /**
     * Creates a `SyntaxErrorException` for the current position in the source.
     *
     * @param null|string $description
     * @return SyntaxErrorException
     */
    protected function createSyntaxErrorException(?string $description = null): SyntaxErrorException
    {
        return new SyntaxErrorException(
            $this->source,
            $this->pos,
            $description ?? $this->unexpectedCharacterMessage($this->readCharCode($this->pos))
        );
    }

    /**
     * Report a message that an unexpected character was encountered.
     *
     * @param int $code
     * @return string
     */
    protected function unexpectedCharacterMessage(int $code): string
    {
        if (isSourceCharacter($code) && !isLineTerminator($code)) {
            return \sprintf('Cannot contain the invalid character %s.', printCharCode($code));
        }

        if ($code === 39) {
            // '
            return 'Unexpected single quote character (\'), did you mean to use a double quote (")?';
        }

        return \sprintf('Cannot parse the unexpected character %s.', printCharCode($code));
    }

    /**
     * @param int $code
     * @return bool
     */
    protected function isSpread(int $code): bool
    {
        return 46 === $code &&
            $this->readCharCode($this->pos + 1) === 46 &&
            $this->readCharCode($this->pos + 2) === 46; // ...
    }

    /**
     * @param int $code
     * @return bool
     */
    protected function isString(int $code): bool
    {
        return 34 === $code && $this->readCharCode($this->pos + 1) !== 34;
    }

    /**
     * @param int $code
     * @return bool
     */
    protected function isTripleQuote(int $code): bool
    {
        return 34 === $code &&
            34 === $this->readCharCode($this->pos + 1) &&
            34 === $this->readCharCode($this->pos + 2); // """
    }

    /**
     * @param int $code
     * @return bool
     */
    protected function isEscapedTripleQuote(int $code): bool
    {
        return $code === 92 &&
            34 === $this->readCharCode($this->pos + 1) &&
            34 === $this->readCharCode($this->pos + 2) &&
            34 === $this->readCharCode($this->pos + 3); // \"""
    }
}


1			<?php
2
3			namespace Digia\GraphQL\Language;
4
5			use Digia\GraphQL\Error\SyntaxErrorException;
6
7			class Lexer implements LexerInterface
8			{
9			protected const ENCODING = 'UTF-8';
10
11			/**
12			* A map between punctuation character code and the corresponding token kind.
13			*
14			* @var array
15			*/
16			protected static $codeTokenKindMap = [
17			33 => TokenKindEnum::BANG,
18			36 => TokenKindEnum::DOLLAR,
19			38 => TokenKindEnum::AMP,
20			40 => TokenKindEnum::PAREN_L,
21			41 => TokenKindEnum::PAREN_R,
22			58 => TokenKindEnum::COLON,
23			61 => TokenKindEnum::EQUALS,
24			64 => TokenKindEnum::AT,
25			91 => TokenKindEnum::BRACKET_L,
26			93 => TokenKindEnum::BRACKET_R,
27			123 => TokenKindEnum::BRACE_L,
28			124 => TokenKindEnum::PIPE,
29			125 => TokenKindEnum::BRACE_R,
30			];
31
32			/**
33			* The source file for this lexer.
34			*
35			* @var Source
36			*/
37			protected $source;
38
39			/**
40			* The contents of the source file.
41			*
42			* @var string
43			*/
44			protected $body;
45
46			/**
47			* The total number of characters in the source file.
48			*
49			* @var int
50			*/
51			protected $bodyLength;
52
53			/**
54			* The options for this lexer.
55			*
56			* @var array
57			*/
58			protected $options = [];
59
60			/**
61			* The previously focused non-ignored token.
62			*
63			* @var Token
64			*/
65			protected $lastToken;
66
67			/**
68			* The currently focused non-ignored token.
69			*
70			* @var Token
71			*/
72			protected $token;
73
74			/**
75			* The current position.
76			*
77			* @var int
78			*/
79			protected $pos;
80
81			/**
82			* The (1-indexed) line containing the current token.
83			*
84			* @var int
85			*/
86			protected $line;
87
88			/**
89			* The character offset at which the current line begins.
90			*
91			* @var int
92			*/
93			protected $lineStart;
94
95			/**
96			* @var array
97			*/
98			protected static $charCodeCache = [];
99
100			/**
101			* Lexer constructor.
102			* @param Source\|null $source
103			* @param array $options
104			*/
105			public function __construct(Source $source, array $options)
106			{
107			$startOfFileToken = $this->createStartOfFileToken();
108
109			$this->lastToken = $startOfFileToken;
110			$this->token = $startOfFileToken;
111			$this->line = 1;
112			$this->lineStart = 0;
113			$this->body = $source->getBody();
114			$this->bodyLength = \strlen($this->body);
115			$this->source = $source;
116			$this->options = $options;
117			}
118
119			/**
120			* @inheritdoc
121			* @throws SyntaxErrorException
122			*/
123			public function advance(): Token
124			{
125			$this->lastToken = $this->token;
126			return $this->token = $this->lookahead();
127			}
128
129			/**
130			* @inheritdoc
131			* @throws SyntaxErrorException
132			*/
133			public function lookahead(): Token
134			{
135			$token = $this->token;
136
137			if (TokenKindEnum::EOF !== $token->getKind()) {
138			do {
139			$next = $this->readToken($token);
140			$token->setNext($next);
141			$token = $next;
142			} while (TokenKindEnum::COMMENT === $token->getKind());
143			}
144
145			return $token;
146			}
147
148			/**
149			* @inheritdoc
150			*/
151			public function getOption(string $name, $default = null)
152			{
153			return $this->options[$name] ?? $default;
154			}
155
156			/**
157			* @inheritdoc
158			*/
159			public function getTokenKind(): string
160			{
161			return $this->token->getKind();
162			}
163
164			/**
165			* @inheritdoc
166			*/
167			public function getTokenValue(): ?string
168			{
169			return $this->token->getValue();
170			}
171
172			/**
173			* @inheritdoc
174			*/
175			public function getToken(): Token
176			{
177			return $this->token;
178			}
179
180			/**
181			* @inheritdoc
182			*/
183			public function getSource(): Source
184			{
185			return $this->source;
186			}
187
188			/**
189			* @inheritdoc
190			*/
191			public function getLastToken(): Token
192			{
193			return $this->lastToken;
194			}
195
196			/**
197			* Reads the token after the given token.
198			*
199			* @param Token $prev
200			* @return Token
201			* @throws SyntaxErrorException
202			*/
203			protected function readToken(Token $prev): Token
204			{
205			$this->pos = $prev->getEnd();
206
207			$this->skipWhitespace();
208
209			$line = $this->line;
210			$col = (1 + $this->pos) - $this->lineStart;
211
212			if ($this->pos >= $this->bodyLength) {
213			return $this->createEndOfFileToken($line, $col, $prev);
214			}
215
216			$code = $this->readCharCode($this->pos);
217
218			// Punctuation: [!$&:=@\|()\[\]{}]{1}
219			if (33 === $code \|\| 36 === $code \|\| 38 === $code \|\| 58 === $code \|\| 61 === $code \|\| 64 === $code \|\| 124 === $code \|\|
220			40 === $code \|\| 41 === $code \|\| 91 === $code \|\| 93 === $code \|\| 123 === $code \|\| 125 === $code) {
221			return $this->lexPunctuation($code, $line, $col, $prev);
222			}
223
224			// Comment: #[\u0009\u0020-\uFFFF]*
225			if (35 === $code) {
226			return $this->lexComment($line, $col, $prev);
227			}
228
229			// Int: -?(0\|[1-9][0-9]*)
230			// Float: -?(0\|[1-9][0-9]*)(\.[0-9]+)?((E\|e)(+\|-)?[0-9]+)?
231			if (45 === $code \|\| isNumber($code)) {
232			return $this->lexNumber($code, $line, $col, $prev);
233			}
234
235			// Name: [_A-Za-z][_0-9A-Za-z]*
236			if (isAlphaNumeric($code)) {
237			return $this->lexName($line, $col, $prev);
238			}
239
240			// Spread: ...
241			if ($this->bodyLength >= 3 && $this->isSpread($code)) {
242			return $this->lexSpread($line, $col, $prev);
243			}
244
245			// String: "([^"\\\u000A\u000D]\|(\\(u[0-9a-fA-F]{4}\|["\\/bfnrt])))*"
246			if ($this->isString($code)) {
247			return $this->lexString($line, $col, $prev);
248			}
249
250			// Block String: """("?"?(\\"""\|\\(?!=""")\|[^"\\]))*"""
251			if ($this->bodyLength >= 3 && $this->isTripleQuote($code)) {
252			return $this->lexBlockString($line, $col, $prev);
253			}
254
255			throw $this->createSyntaxErrorException();
256			}
257
258			/**
259			* @return Token
260			*/
261			protected function createStartOfFileToken(): Token
262			{
263			return new Token(TokenKindEnum::SOF);
264			}
265
266			/**
267			* Creates an End Of File (EOF) token.
268			*
269			* @param int $line
270			* @param int $col
271			* @param Token $prev
272			* @return Token
273			*/
274			protected function createEndOfFileToken(int $line, int $col, Token $prev): Token
275			{
276			return new Token(TokenKindEnum::EOF, $this->bodyLength, $this->bodyLength, $line, $col, $prev);
277			}
278
279			/**
280			* Reads a punctuation token from the source file.
281			*
282			* @param int $code
283			* @param int $line
284			* @param int $col
285			* @param Token $prev
286			* @return Token
287			* @throws SyntaxErrorException
288			*/
289			protected function lexPunctuation(int $code, int $line, int $col, Token $prev): ?Token
290			{
291			if (!isset(self::$codeTokenKindMap[$code])) {
292			throw $this->createSyntaxErrorException();
293			}
294
295			return new Token(self::$codeTokenKindMap[$code], $this->pos, $this->pos + 1, $line, $col, $prev);
296			}
297
298			/**
299			* Reads a name token from the source file.
300			*
301			* @param int $line
302			* @param int $col
303			* @param Token $prev
304			* @return Token
305			*/
306			protected function lexName(int $line, int $col, Token $prev): Token
307			{
308			$start = $this->pos;
309
310			++$this->pos;
311
312			while ($this->pos !== $this->bodyLength &&
313			($code = $this->readCharCode($this->pos)) !== null &&
314			isAlphaNumeric($code)) {
315			++$this->pos;
316			}
317
318			$value = sliceString($this->body, $start, $this->pos);
319
320			return new Token(TokenKindEnum::NAME, $start, $this->pos, $line, $col, $prev, $value);
321			}
322
323			/**
324			* Reads a number (int or float) token from the source file.
325			*
326			* @param int $code
327			* @param int $line
328			* @param int $col
329			* @param Token $prev
330			* @return Token
331			* @throws SyntaxErrorException
332			*/
333			protected function lexNumber(int $code, int $line, int $col, Token $prev): Token
334			{
335			$start = $this->pos;
336			$isFloat = false;
337
338			if (45 === $code) {
339			// -
340			$code = $this->readCharCode(++$this->pos);
341			}
342
343			if (48 === $code) {
344			// 0
345			$code = $this->readCharCode(++$this->pos);
346
347			if (isNumber($code)) {
348			throw $this->createSyntaxErrorException(
349			\sprintf('Invalid number, unexpected digit after 0: %s.', printCharCode($code))
350			);
351			}
352			} else {
353			$this->skipDigits($code);
354			$code = $this->readCharCode($this->pos);
355			}
356
357			if (46 === $code) {
358			// .
359			$isFloat = true;
360
361			$code = $this->readCharCode(++$this->pos);
362			$this->skipDigits($code);
363			$code = $this->readCharCode($this->pos);
364			}
365
366			if (69 === $code \|\| 101 === $code) {
367			// e or E
368			$isFloat = true;
369
370			$code = $this->readCharCode(++$this->pos);
371
372			if (43 === $code \|\| 45 === $code) {
373			// + or -
374			$code = $this->readCharCode(++$this->pos);
375			}
376
377			$this->skipDigits($code);
378			}
379
380			return new Token(
381			$isFloat ? TokenKindEnum::FLOAT : TokenKindEnum::INT,
382			$start,
383			$this->pos,
384			$line,
385			$col,
386			$prev,
387			sliceString($this->body, $start, $this->pos)
388			);
389			}
390
391			/**
392			* Skips digits at the current position.
393			*
394			* @param int $code
395			* @throws SyntaxErrorException
396			*/
397			protected function skipDigits(int $code): void
398			{
399			if (isNumber($code)) {
400			do {
401			$code = $this->readCharCode(++$this->pos);
402			} while (isNumber($code));
403
404			return;
405			}
406
407			throw $this->createSyntaxErrorException(
408			\sprintf('Invalid number, expected digit but got: %s.', printCharCode($code))
409			);
410			}
411
412			/**
413			* Reads a comment token from the source file.
414			*
415			* @param int $line
416			* @param int $col
417			* @param Token $prev
418			* @return Token
419			*/
420			protected function lexComment(int $line, int $col, Token $prev): Token
421			{
422			$start = $this->pos;
423
424			do {
425			$code = $this->readCharCode(++$this->pos);
426			} while ($code !== null && ($code > 0x001f \|\| 0x0009 === $code)); // SourceCharacter but not LineTerminator
427
428			return new Token(
429			TokenKindEnum::COMMENT,
430			$start,
431			$this->pos,
432			$line,
433			$col,
434			$prev,
435			sliceString($this->body, $start + 1, $this->pos)
436			);
437			}
438
439			/**
440			* Reads a spread token from the source.
441			*
442			* @param int $line
443			* @param int $col
444			* @param Token $prev
445			* @return Token
446			*/
447			protected function lexSpread(int $line, int $col, Token $prev): Token
448			{
449			return new Token(TokenKindEnum::SPREAD, $this->pos, $this->pos + 3, $line, $col, $prev);
450			}
451
452			/**
453			* Reads a string token from the source.
454			*
455			* @param int $line
456			* @param int $col
457			* @param Token $prev
458			* @return Token
459			* @throws SyntaxErrorException
460			*/
461			protected function lexString(int $line, int $col, Token $prev): Token
462			{
463			$start = $this->pos;
464			$chunkStart = ++$this->pos; // skip the quote
465			$value = '';
466
467			while ($this->pos < $this->bodyLength &&
468			($code = $this->readCharCode($this->pos)) !== null && !isLineTerminator($code)) {
469			// Closing Quote (")
470			if (34 === $code) {
471			$value .= sliceString($this->body, $chunkStart, $this->pos);
472			return new Token(TokenKindEnum::STRING, $start, $this->pos + 1, $line, $col, $prev, $value);
473			}
474
475			if (isSourceCharacter($code)) {
476			throw $this->createSyntaxErrorException(
477			\sprintf('Invalid character within String: %s.', printCharCode($code))
478			);
479			}
480
481			++$this->pos;
482
483			if (92 === $code) {
484			// \
485			$value .= sliceString($this->body, $chunkStart, $this->pos - 1);
486
487			$code = $this->readCharCode($this->pos);
488
489			switch ($code) {
490			case 34: // "
491			$value .= '"';
492			break;
493			case 47: // /
494			$value .= '/';
495			break;
496			case 92: // \
497			$value .= '\\';
498			break;
499			case 98: // b
500			$value .= '\b';
501			break;
502			case 102: // f
503			$value .= '\f';
504			break;
505			case 110: // n
506			$value .= '\n';
507			break;
508			case 114: // r
509			$value .= '\r';
510			break;
511			case 116: // t
512			$value .= '\t';
513			break;
514			case 117: // u
515			$unicodeString = sliceString($this->body, $this->pos + 1, $this->pos + 5);
516
517			if (!\preg_match('/[0-9A-Fa-f]{4}/', $unicodeString)) {
518			throw $this->createSyntaxErrorException(
519			\sprintf('Invalid character escape sequence: \\u%s.', $unicodeString)
520			);
521			}
522
523			$value .= '\\u' . $unicodeString;
524			$this->pos += 4;
525
526			break;
527			default:
528			throw $this->createSyntaxErrorException(
529			\sprintf('Invalid character escape sequence: \\%s.', \chr($code))
530			);
531			}
532
533			++$this->pos;
534
535			$chunkStart = $this->pos;
536			}
537			}
538
539			throw $this->createSyntaxErrorException('Unterminated string.');
540			}
541
542			/**
543			* Reads a block string token from the source file.
544			*
545			* @param int $line
546			* @param int $col
547			* @param Token $prev
548			* @return Token
549			* @throws SyntaxErrorException
550			*/
551			protected function lexBlockString(int $line, int $col, Token $prev): Token
552			{
553			$start = $this->pos;
554			$this->pos = $start + 3; // skip the triple-quote
555			$chunkStart = $this->pos;
556			$rawValue = '';
557
558			while ($this->pos < $this->bodyLength && ($code = $this->readCharCode($this->pos)) !== null) {
559			// Closing Triple-Quote (""")
560			if ($this->isTripleQuote($code)) {
561			$rawValue .= sliceString($this->body, $chunkStart, $this->pos);
562			return new Token(
563			TokenKindEnum::BLOCK_STRING,
564			$start,
565			$this->pos + 3,
566			$line,
567			$col,
568			$prev,
569			blockStringValue($rawValue)
570			);
571			}
572
573			if (isSourceCharacter($code) && !isLineTerminator($code)) {
574			throw $this->createSyntaxErrorException(
575			\sprintf('Invalid character within String: %s.', printCharCode($code))
576			);
577			}
578
579			if ($this->isEscapedTripleQuote($code)) {
580			$rawValue .= sliceString($this->body, $chunkStart, $this->pos) . '"""';
581			$this->pos += 4;
582			$chunkStart = $this->pos;
583			} else {
584			++$this->pos;
585			}
586			}
587
588			throw $this->createSyntaxErrorException('Unterminated string.');
589			}
590
591			/**
592			* Skips whitespace at the current position.
593			*/
594			protected function skipWhitespace(): void
595			{
596			while ($this->pos < $this->bodyLength) {
597			$code = $this->readCharCode($this->pos);
598
599			if (9 === $code \|\| 32 === $code \|\| 44 === $code \|\| 0xfeff === $code) {
600			// tab \| space \| comma \| BOM
601			++$this->pos;
602			} elseif (10 === $code) {
603			// new line (\n)
604			++$this->pos;
605			++$this->line;
606			$this->lineStart = $this->pos;
607			} elseif (13 === $code) {
608			// carriage return (\r)
609			if (10 === $this->readCharCode($this->pos + 1)) {
610			// carriage return and new line (\r\n)
611			$this->pos += 2;
612			} else {
613			++$this->pos;
614			}
615			++$this->line;
616			$this->lineStart = $this->pos;
617			} else {
618			break;
619			}
620			}
621			}
622
623			/**
624			* @param int $pos
625			* @return int
626			*/
627			protected function readCharCode(int $pos): int
628			{
629			$char = \mb_substr($this->body, $pos, 1, self::ENCODING);
630
631			if ('' === $char) {
632			return 0;
633			}
634
635			if (!isset(self::$charCodeCache[$char])) {
636			self::$charCodeCache[$char] = \mb_ord($char, self::ENCODING);
637			}
638
639			return self::$charCodeCache[$char];
640			}
641
642			/**
643			* Creates a `SyntaxErrorException` for the current position in the source.
644			*
645			* @param null\|string $description
646			* @return SyntaxErrorException
647			*/
648			protected function createSyntaxErrorException(?string $description = null): SyntaxErrorException
649			{
650			return new SyntaxErrorException(
651			$this->source,
652			$this->pos,
653			$description ?? $this->unexpectedCharacterMessage($this->readCharCode($this->pos))
654			);
655			}
656
657			/**
658			* Report a message that an unexpected character was encountered.
659			*
660			* @param int $code
661			* @return string
662			*/
663			protected function unexpectedCharacterMessage(int $code): string
664			{
665			if (isSourceCharacter($code) && !isLineTerminator($code)) {
666			return \sprintf('Cannot contain the invalid character %s.', printCharCode($code));
667			}
668
669			if ($code === 39) {
670			// '
671			return 'Unexpected single quote character (\'), did you mean to use a double quote (")?';
672			}
673
674			return \sprintf('Cannot parse the unexpected character %s.', printCharCode($code));
675			}
676
677			/**
678			* @param int $code
679			* @return bool
680			*/
681			protected function isSpread(int $code): bool
682			{
683			return 46 === $code &&
684			$this->readCharCode($this->pos + 1) === 46 &&
685			$this->readCharCode($this->pos + 2) === 46; // ...
686			}
687
688			/**
689			* @param int $code
690			* @return bool
691			*/
692			protected function isString(int $code): bool
693			{
694			return 34 === $code && $this->readCharCode($this->pos + 1) !== 34;
695			}
696
697			/**
698			* @param int $code
699			* @return bool
700			*/
701			protected function isTripleQuote(int $code): bool
702			{
703			return 34 === $code &&
704			34 === $this->readCharCode($this->pos + 1) &&
705			34 === $this->readCharCode($this->pos + 2); // """
706			}
707
708			/**
709			* @param int $code
710			* @return bool
711			*/
712			protected function isEscapedTripleQuote(int $code): bool
713			{
714			return $code === 92 &&
715			34 === $this->readCharCode($this->pos + 1) &&
716			34 === $this->readCharCode($this->pos + 2) &&
717			34 === $this->readCharCode($this->pos + 3); // \"""
718			}
719			}
720

digiaonline / graphql-php

Pull Request — master (#196)

Lexer::readToken() C

Complexity

Size

Duplication

Importance

How to fix Long Method Complexity

Long Method

Duplication Side-by-Side

Filter issues like