Subversion-Projekte lars-tiefland.laravel_shop

<?php declare(strict_types=1);

namespace PhpParser;

/*

 * This parser is based on a skeleton written by Moriyoshi Koizumi, which in

 * turn is based on work by Masato Bito.

 */

use PhpParser\Node\Expr;

use PhpParser\Node\Expr\Cast\Double;

use PhpParser\Node\Name;

use PhpParser\Node\Param;

use PhpParser\Node\Scalar\Encapsed;

use PhpParser\Node\Scalar\LNumber;

use PhpParser\Node\Scalar\String_;

use PhpParser\Node\Stmt\Class_;

use PhpParser\Node\Stmt\ClassConst;

use PhpParser\Node\Stmt\ClassMethod;

use PhpParser\Node\Stmt\Else_;

use PhpParser\Node\Stmt\ElseIf_;

use PhpParser\Node\Stmt\Enum_;

use PhpParser\Node\Stmt\Interface_;

use PhpParser\Node\Stmt\Namespace_;

use PhpParser\Node\Stmt\Nop;

use PhpParser\Node\Stmt\Property;

use PhpParser\Node\Stmt\TryCatch;

use PhpParser\Node\Stmt\UseUse;

use PhpParser\Node\VarLikeIdentifier;

abstract class ParserAbstract implements Parser

{

    const SYMBOL_NONE = -1;

    /*

     * The following members will be filled with generated parsing data:

     */

    /** @var int Size of $tokenToSymbol map */

    protected $tokenToSymbolMapSize;

    /** @var int Size of $action table */

    protected $actionTableSize;

    /** @var int Size of $goto table */

    protected $gotoTableSize;

    /** @var int Symbol number signifying an invalid token */

    protected $invalidSymbol;

    /** @var int Symbol number of error recovery token */

    protected $errorSymbol;

    /** @var int Action number signifying default action */

    protected $defaultAction;

    /** @var int Rule number signifying that an unexpected token was encountered */

    protected $unexpectedTokenRule;

    protected $YY2TBLSTATE;

    /** @var int Number of non-leaf states */

    protected $numNonLeafStates;

    /** @var int[] Map of lexer tokens to internal symbols */

    protected $tokenToSymbol;

    /** @var string[] Map of symbols to their names */

    protected $symbolToName;

    /** @var array Names of the production rules (only necessary for debugging) */

    protected $productions;

    /** @var int[] Map of states to a displacement into the $action table. The corresponding action for this

     *             state/symbol pair is $action[$actionBase[$state] + $symbol]. If $actionBase[$state] is 0, the

     *             action is defaulted, i.e. $actionDefault[$state] should be used instead. */

    protected $actionBase;

    /** @var int[] Table of actions. Indexed according to $actionBase comment. */

    protected $action;

    /** @var int[] Table indexed analogously to $action. If $actionCheck[$actionBase[$state] + $symbol] != $symbol

     *             then the action is defaulted, i.e. $actionDefault[$state] should be used instead. */

    protected $actionCheck;

    /** @var int[] Map of states to their default action */

    protected $actionDefault;

    /** @var callable[] Semantic action callbacks */

    protected $reduceCallbacks;

    /** @var int[] Map of non-terminals to a displacement into the $goto table. The corresponding goto state for this

     *             non-terminal/state pair is $goto[$gotoBase[$nonTerminal] + $state] (unless defaulted) */

    protected $gotoBase;

    /** @var int[] Table of states to goto after reduction. Indexed according to $gotoBase comment. */

    protected $goto;

    /** @var int[] Table indexed analogously to $goto. If $gotoCheck[$gotoBase[$nonTerminal] + $state] != $nonTerminal

     *             then the goto state is defaulted, i.e. $gotoDefault[$nonTerminal] should be used. */

    protected $gotoCheck;

    /** @var int[] Map of non-terminals to the default state to goto after their reduction */

    protected $gotoDefault;

    /** @var int[] Map of rules to the non-terminal on their left-hand side, i.e. the non-terminal to use for

     *             determining the state to goto after reduction. */

    protected $ruleToNonTerminal;

    /** @var int[] Map of rules to the length of their right-hand side, which is the number of elements that have to

     *             be popped from the stack(s) on reduction. */

    protected $ruleToLength;

    /*

     * The following members are part of the parser state:

     */

    /** @var Lexer Lexer that is used when parsing */

    protected $lexer;

    /** @var mixed Temporary value containing the result of last semantic action (reduction) */

    protected $semValue;

    /** @var array Semantic value stack (contains values of tokens and semantic action results) */

    protected $semStack;

    /** @var array[] Start attribute stack */

    protected $startAttributeStack;

    /** @var array[] End attribute stack */

    protected $endAttributeStack;

    /** @var array End attributes of last *shifted* token */

    protected $endAttributes;

    /** @var array Start attributes of last *read* token */

    protected $lookaheadStartAttributes;

    /** @var ErrorHandler Error handler */

    protected $errorHandler;

    /** @var int Error state, used to avoid error floods */

    protected $errorState;

    /**

     * Initialize $reduceCallbacks map.

     */

    abstract protected function initReduceCallbacks();

    /**

     * Creates a parser instance.

     *

     * Options: Currently none.

     *

     * @param Lexer $lexer A lexer

     * @param array $options Options array.

     */

    public function __construct(Lexer $lexer, array $options = []) {

        $this->lexer = $lexer;

        if (isset($options['throwOnError'])) {

            throw new \LogicException(

                '"throwOnError" is no longer supported, use "errorHandler" instead');

        }

        $this->initReduceCallbacks();

    }

    /**

     * Parses PHP code into a node tree.

     *

     * If a non-throwing error handler is used, the parser will continue parsing after an error

     * occurred and attempt to build a partial AST.

     *

     * @param string $code The source code to parse

     * @param ErrorHandler|null $errorHandler Error handler to use for lexer/parser errors, defaults

     *                                        to ErrorHandler\Throwing.

     *

     * @return Node\Stmt[]|null Array of statements (or null non-throwing error handler is used and

     *                          the parser was unable to recover from an error).

     */

    public function parse(string $code, ErrorHandler $errorHandler = null) {

        $this->errorHandler = $errorHandler ?: new ErrorHandler\Throwing;

        $this->lexer->startLexing($code, $this->errorHandler);

        $result = $this->doParse();

        // Clear out some of the interior state, so we don't hold onto unnecessary

        // memory between uses of the parser

        $this->startAttributeStack = [];

        $this->endAttributeStack = [];

        $this->semStack = [];

        $this->semValue = null;

        return $result;

    }

    protected function doParse() {

        // We start off with no lookahead-token

        $symbol = self::SYMBOL_NONE;

        // The attributes for a node are taken from the first and last token of the node.

        // From the first token only the startAttributes are taken and from the last only

        // the endAttributes. Both are merged using the array union operator (+).

        $startAttributes = [];

        $endAttributes = [];

        $this->endAttributes = $endAttributes;

        // Keep stack of start and end attributes

        $this->startAttributeStack = [];

        $this->endAttributeStack = [$endAttributes];

        // Start off in the initial state and keep a stack of previous states

        $state = 0;

        $stateStack = [$state];

        // Semantic value stack (contains values of tokens and semantic action results)

        $this->semStack = [];

        // Current position in the stack(s)

        $stackPos = 0;

        $this->errorState = 0;

        for (;;) {

            //$this->traceNewState($state, $symbol);

            if ($this->actionBase[$state] === 0) {

                $rule = $this->actionDefault[$state];

            } else {

                if ($symbol === self::SYMBOL_NONE) {

                    // Fetch the next token id from the lexer and fetch additional info by-ref.

                    // The end attributes are fetched into a temporary variable and only set once the token is really

                    // shifted (not during read). Otherwise you would sometimes get off-by-one errors, when a rule is

                    // reduced after a token was read but not yet shifted.

                    $tokenId = $this->lexer->getNextToken($tokenValue, $startAttributes, $endAttributes);

                    // map the lexer token id to the internally used symbols

                    $symbol = $tokenId >= 0 && $tokenId < $this->tokenToSymbolMapSize

                        ? $this->tokenToSymbol[$tokenId]

                        : $this->invalidSymbol;

                    if ($symbol === $this->invalidSymbol) {

                        throw new \RangeException(sprintf(

                            'The lexer returned an invalid token (id=%d, value=%s)',

                            $tokenId, $tokenValue

                        ));

                    }

                    // Allow productions to access the start attributes of the lookahead token.

                    $this->lookaheadStartAttributes = $startAttributes;

                    //$this->traceRead($symbol);

                }

                $idx = $this->actionBase[$state] + $symbol;

                if ((($idx >= 0 && $idx < $this->actionTableSize && $this->actionCheck[$idx] === $symbol)

                     || ($state < $this->YY2TBLSTATE

                         && ($idx = $this->actionBase[$state + $this->numNonLeafStates] + $symbol) >= 0

                         && $idx < $this->actionTableSize && $this->actionCheck[$idx] === $symbol))

                    && ($action = $this->action[$idx]) !== $this->defaultAction) {

                    /*

                     * >= numNonLeafStates: shift and reduce

                     * > 0: shift

                     * = 0: accept

                     * < 0: reduce

                     * = -YYUNEXPECTED: error

                     */

                    if ($action > 0) {

                        /* shift */

                        //$this->traceShift($symbol);

                        ++$stackPos;

                        $stateStack[$stackPos] = $state = $action;

                        $this->semStack[$stackPos] = $tokenValue;

                        $this->startAttributeStack[$stackPos] = $startAttributes;

                        $this->endAttributeStack[$stackPos] = $endAttributes;

                        $this->endAttributes = $endAttributes;

                        $symbol = self::SYMBOL_NONE;

                        if ($this->errorState) {

                            --$this->errorState;

                        }

                        if ($action < $this->numNonLeafStates) {

                            continue;

                        }

                        /* $yyn >= numNonLeafStates means shift-and-reduce */

                        $rule = $action - $this->numNonLeafStates;

                    } else {

                        $rule = -$action;

                    }

                } else {

                    $rule = $this->actionDefault[$state];

                }

            }

            for (;;) {

                if ($rule === 0) {

                    /* accept */

                    //$this->traceAccept();

                    return $this->semValue;

                } elseif ($rule !== $this->unexpectedTokenRule) {

                    /* reduce */

                    //$this->traceReduce($rule);

                    try {

                        $this->reduceCallbacks[$rule]($stackPos);

                    } catch (Error $e) {

                        if (-1 === $e->getStartLine() && isset($startAttributes['startLine'])) {

                            $e->setStartLine($startAttributes['startLine']);

                        }

                        $this->emitError($e);

                        // Can't recover from this type of error

                        return null;

                    }

                    /* Goto - shift nonterminal */

                    $lastEndAttributes = $this->endAttributeStack[$stackPos];

                    $ruleLength = $this->ruleToLength[$rule];

                    $stackPos -= $ruleLength;

                    $nonTerminal = $this->ruleToNonTerminal[$rule];

                    $idx = $this->gotoBase[$nonTerminal] + $stateStack[$stackPos];

                    if ($idx >= 0 && $idx < $this->gotoTableSize && $this->gotoCheck[$idx] === $nonTerminal) {

                        $state = $this->goto[$idx];

                    } else {

                        $state = $this->gotoDefault[$nonTerminal];

                    }

                    ++$stackPos;

                    $stateStack[$stackPos]     = $state;

                    $this->semStack[$stackPos] = $this->semValue;

                    $this->endAttributeStack[$stackPos] = $lastEndAttributes;

                    if ($ruleLength === 0) {

                        // Empty productions use the start attributes of the lookahead token.

                        $this->startAttributeStack[$stackPos] = $this->lookaheadStartAttributes;

                    }

                } else {

                    /* error */

                    switch ($this->errorState) {

                        case 0:

                            $msg = $this->getErrorMessage($symbol, $state);

                            $this->emitError(new Error($msg, $startAttributes + $endAttributes));

                            // Break missing intentionally

                        case 1:

                        case 2:

                            $this->errorState = 3;

                            // Pop until error-expecting state uncovered

                            while (!(

                                (($idx = $this->actionBase[$state] + $this->errorSymbol) >= 0

                                    && $idx < $this->actionTableSize && $this->actionCheck[$idx] === $this->errorSymbol)

                                || ($state < $this->YY2TBLSTATE

                                    && ($idx = $this->actionBase[$state + $this->numNonLeafStates] + $this->errorSymbol) >= 0

                                    && $idx < $this->actionTableSize && $this->actionCheck[$idx] === $this->errorSymbol)

                            ) || ($action = $this->action[$idx]) === $this->defaultAction) { // Not totally sure about this

                                if ($stackPos <= 0) {

                                    // Could not recover from error

                                    return null;

                                }

                                $state = $stateStack[--$stackPos];

                                //$this->tracePop($state);

                            }

                            //$this->traceShift($this->errorSymbol);

                            ++$stackPos;

                            $stateStack[$stackPos] = $state = $action;

                            // We treat the error symbol as being empty, so we reset the end attributes

                            // to the end attributes of the last non-error symbol

                            $this->startAttributeStack[$stackPos] = $this->lookaheadStartAttributes;

                            $this->endAttributeStack[$stackPos] = $this->endAttributeStack[$stackPos - 1];

                            $this->endAttributes = $this->endAttributeStack[$stackPos - 1];

                            break;

                        case 3:

                            if ($symbol === 0) {

                                // Reached EOF without recovering from error

                                return null;

                            }

                            //$this->traceDiscard($symbol);

                            $symbol = self::SYMBOL_NONE;

                            break 2;

                    }

                }

                if ($state < $this->numNonLeafStates) {

                    break;

                }

                /* >= numNonLeafStates means shift-and-reduce */

                $rule = $state - $this->numNonLeafStates;

            }

        }

        throw new \RuntimeException('Reached end of parser loop');

    }

    protected function emitError(Error $error) {

        $this->errorHandler->handleError($error);

    }

    /**

     * Format error message including expected tokens.

     *

     * @param int $symbol Unexpected symbol

     * @param int $state  State at time of error

     *

     * @return string Formatted error message

     */

    protected function getErrorMessage(int $symbol, int $state) : string {

        $expectedString = '';

        if ($expected = $this->getExpectedTokens($state)) {

            $expectedString = ', expecting ' . implode(' or ', $expected);

        }

        return 'Syntax error, unexpected ' . $this->symbolToName[$symbol] . $expectedString;

    }

    /**

     * Get limited number of expected tokens in given state.

     *

     * @param int $state State

     *

     * @return string[] Expected tokens. If too many, an empty array is returned.

     */

    protected function getExpectedTokens(int $state) : array {

        $expected = [];

        $base = $this->actionBase[$state];

        foreach ($this->symbolToName as $symbol => $name) {

            $idx = $base + $symbol;

            if ($idx >= 0 && $idx < $this->actionTableSize && $this->actionCheck[$idx] === $symbol

                || $state < $this->YY2TBLSTATE

                && ($idx = $this->actionBase[$state + $this->numNonLeafStates] + $symbol) >= 0

                && $idx < $this->actionTableSize && $this->actionCheck[$idx] === $symbol

            ) {

                if ($this->action[$idx] !== $this->unexpectedTokenRule

                    && $this->action[$idx] !== $this->defaultAction

                    && $symbol !== $this->errorSymbol

                ) {

                    if (count($expected) === 4) {

                        /* Too many expected tokens */

                        return [];

                    }

                    $expected[] = $name;

                }

            }

        }

        return $expected;

    }

    /*

     * Tracing functions used for debugging the parser.

     */

    /*

    protected function traceNewState($state, $symbol) {

        echo '% State ' . $state

            . ', Lookahead ' . ($symbol == self::SYMBOL_NONE ? '--none--' : $this->symbolToName[$symbol]) . "\n";

    }

    protected function traceRead($symbol) {

        echo '% Reading ' . $this->symbolToName[$symbol] . "\n";

    }

    protected function traceShift($symbol) {

        echo '% Shift ' . $this->symbolToName[$symbol] . "\n";

    }

    protected function traceAccept() {

        echo "% Accepted.\n";

    }

    protected function traceReduce($n) {

        echo '% Reduce by (' . $n . ') ' . $this->productions[$n] . "\n";

    }

    protected function tracePop($state) {

        echo '% Recovering, uncovered state ' . $state . "\n";

    }

    protected function traceDiscard($symbol) {

        echo '% Discard ' . $this->symbolToName[$symbol] . "\n";

    }

    */

    /*

     * Helper functions invoked by semantic actions

     */

    /**

     * Moves statements of semicolon-style namespaces into $ns->stmts and checks various error conditions.

     *

     * @param Node\Stmt[] $stmts

     * @return Node\Stmt[]

     */

    protected function handleNamespaces(array $stmts) : array {

        $hasErrored = false;

        $style = $this->getNamespacingStyle($stmts);

        if (null === $style) {

            // not namespaced, nothing to do

            return $stmts;

        } elseif ('brace' === $style) {

            // For braced namespaces we only have to check that there are no invalid statements between the namespaces

            $afterFirstNamespace = false;

            foreach ($stmts as $stmt) {

                if ($stmt instanceof Node\Stmt\Namespace_) {

                    $afterFirstNamespace = true;

                } elseif (!$stmt instanceof Node\Stmt\HaltCompiler

                        && !$stmt instanceof Node\Stmt\Nop

                        && $afterFirstNamespace && !$hasErrored) {

                    $this->emitError(new Error(

                        'No code may exist outside of namespace {}', $stmt->getAttributes()));

                    $hasErrored = true; // Avoid one error for every statement

                }

            }

            return $stmts;

        } else {

            // For semicolon namespaces we have to move the statements after a namespace declaration into ->stmts

            $resultStmts = [];

            $targetStmts =& $resultStmts;

            $lastNs = null;

            foreach ($stmts as $stmt) {

                if ($stmt instanceof Node\Stmt\Namespace_) {

                    if ($lastNs !== null) {

                        $this->fixupNamespaceAttributes($lastNs);

                    }

                    if ($stmt->stmts === null) {

                        $stmt->stmts = [];

                        $targetStmts =& $stmt->stmts;

                        $resultStmts[] = $stmt;

                    } else {

                        // This handles the invalid case of mixed style namespaces

                        $resultStmts[] = $stmt;

                        $targetStmts =& $resultStmts;

                    }

                    $lastNs = $stmt;

                } elseif ($stmt instanceof Node\Stmt\HaltCompiler) {

                    // __halt_compiler() is not moved into the namespace

                    $resultStmts[] = $stmt;

                } else {

                    $targetStmts[] = $stmt;

                }

            }

            if ($lastNs !== null) {

                $this->fixupNamespaceAttributes($lastNs);

            }

            return $resultStmts;

        }

    }

    private function fixupNamespaceAttributes(Node\Stmt\Namespace_ $stmt) {

        // We moved the statements into the namespace node, as such the end of the namespace node

        // needs to be extended to the end of the statements.

        if (empty($stmt->stmts)) {

            return;

        }

        // We only move the builtin end attributes here. This is the best we can do with the

        // knowledge we have.

        $endAttributes = ['endLine', 'endFilePos', 'endTokenPos'];

        $lastStmt = $stmt->stmts[count($stmt->stmts) - 1];

        foreach ($endAttributes as $endAttribute) {

            if ($lastStmt->hasAttribute($endAttribute)) {

                $stmt->setAttribute($endAttribute, $lastStmt->getAttribute($endAttribute));

            }

        }

    }

    /**

     * Determine namespacing style (semicolon or brace)

     *

     * @param Node[] $stmts Top-level statements.

     *

     * @return null|string One of "semicolon", "brace" or null (no namespaces)

     */

    private function getNamespacingStyle(array $stmts) {

        $style = null;

        $hasNotAllowedStmts = false;

        foreach ($stmts as $i => $stmt) {

            if ($stmt instanceof Node\Stmt\Namespace_) {

                $currentStyle = null === $stmt->stmts ? 'semicolon' : 'brace';

                if (null === $style) {

                    $style = $currentStyle;

                    if ($hasNotAllowedStmts) {

                        $this->emitError(new Error(

                            'Namespace declaration statement has to be the very first statement in the script',

                            $stmt->getLine() // Avoid marking the entire namespace as an error

                        ));

                    }

                } elseif ($style !== $currentStyle) {

                    $this->emitError(new Error(

                        'Cannot mix bracketed namespace declarations with unbracketed namespace declarations',

                        $stmt->getLine() // Avoid marking the entire namespace as an error

                    ));

                    // Treat like semicolon style for namespace normalization

                    return 'semicolon';

                }

                continue;

            }

            /* declare(), __halt_compiler() and nops can be used before a namespace declaration */

            if ($stmt instanceof Node\Stmt\Declare_

                || $stmt instanceof Node\Stmt\HaltCompiler

                || $stmt instanceof Node\Stmt\Nop) {

                continue;

            }

            /* There may be a hashbang line at the very start of the file */

            if ($i === 0 && $stmt instanceof Node\Stmt\InlineHTML && preg_match('/\A#!.*\r?\n\z/', $stmt->value)) {

                continue;

            }

            /* Everything else if forbidden before namespace declarations */

            $hasNotAllowedStmts = true;

        }

        return $style;

    }

    /**

     * Fix up parsing of static property calls in PHP 5.

     *

     * In PHP 5 A::$b[c][d] and A::$b[c][d]() have very different interpretation. The former is

     * interpreted as (A::$b)[c][d], while the latter is the same as A::{$b[c][d]}(). We parse the

     * latter as the former initially and this method fixes the AST into the correct form when we

     * encounter the "()".

     *

     * @param  Node\Expr\StaticPropertyFetch|Node\Expr\ArrayDimFetch $prop

     * @param  Node\Arg[] $args

     * @param  array      $attributes

     *

     * @return Expr\StaticCall

     */

    protected function fixupPhp5StaticPropCall($prop, array $args, array $attributes) : Expr\StaticCall {

        if ($prop instanceof Node\Expr\StaticPropertyFetch) {

            $name = $prop->name instanceof VarLikeIdentifier

                ? $prop->name->toString() : $prop->name;

            $var = new Expr\Variable($name, $prop->name->getAttributes());

            return new Expr\StaticCall($prop->class, $var, $args, $attributes);

        } elseif ($prop instanceof Node\Expr\ArrayDimFetch) {

            $tmp = $prop;

            while ($tmp->var instanceof Node\Expr\ArrayDimFetch) {

                $tmp = $tmp->var;

            }

            /** @var Expr\StaticPropertyFetch $staticProp */

            $staticProp = $tmp->var;

            // Set start attributes to attributes of innermost node

            $tmp = $prop;

            $this->fixupStartAttributes($tmp, $staticProp->name);

            while ($tmp->var instanceof Node\Expr\ArrayDimFetch) {

                $tmp = $tmp->var;

                $this->fixupStartAttributes($tmp, $staticProp->name);

            }

            $name = $staticProp->name instanceof VarLikeIdentifier

                ? $staticProp->name->toString() : $staticProp->name;

            $tmp->var = new Expr\Variable($name, $staticProp->name->getAttributes());

            return new Expr\StaticCall($staticProp->class, $prop, $args, $attributes);

        } else {

            throw new \Exception;

        }

    }

    protected function fixupStartAttributes(Node $to, Node $from) {

        $startAttributes = ['startLine', 'startFilePos', 'startTokenPos'];

        foreach ($startAttributes as $startAttribute) {

            if ($from->hasAttribute($startAttribute)) {

                $to->setAttribute($startAttribute, $from->getAttribute($startAttribute));

            }

        }

    }

    protected function handleBuiltinTypes(Name $name) {

        $builtinTypes = [

            'bool'     => true,

            'int'      => true,

            'float'    => true,

            'string'   => true,

            'iterable' => true,

            'void'     => true,

            'object'   => true,

            'null'     => true,

            'false'    => true,

            'mixed'    => true,

            'never'    => true,

            'true'     => true,

        ];

        if (!$name->isUnqualified()) {

            return $name;

        }

        $lowerName = $name->toLowerString();

        if (!isset($builtinTypes[$lowerName])) {

            return $name;

        }

        return new Node\Identifier($lowerName, $name->getAttributes());

    }

    /**

     * Get combined start and end attributes at a stack location

     *

     * @param int $pos Stack location

     *

     * @return array Combined start and end attributes

     */

    protected function getAttributesAt(int $pos) : array {

        return $this->startAttributeStack[$pos] + $this->endAttributeStack[$pos];

    }

    protected function getFloatCastKind(string $cast): int

    {

        $cast = strtolower($cast);

        if (strpos($cast, 'float') !== false) {

            return Double::KIND_FLOAT;

        }

        if (strpos($cast, 'real') !== false) {

            return Double::KIND_REAL;

        }

        return Double::KIND_DOUBLE;

    }

    protected function parseLNumber($str, $attributes, $allowInvalidOctal = false) {

        try {

            return LNumber::fromString($str, $attributes, $allowInvalidOctal);

        } catch (Error $error) {

            $this->emitError($error);

            // Use dummy value

            return new LNumber(0, $attributes);

        }

    }

    /**

     * Parse a T_NUM_STRING token into either an integer or string node.

     *

     * @param string $str        Number string

     * @param array  $attributes Attributes

     *

     * @return LNumber|String_ Integer or string node.

     */

    protected function parseNumString(string $str, array $attributes) {

        if (!preg_match('/^(?:0|-?[1-9][0-9]*)$/', $str)) {

            return new String_($str, $attributes);

        }

        $num = +$str;

        if (!is_int($num)) {

            return new String_($str, $attributes);

        }

        return new LNumber($num, $attributes);

    }

    protected function stripIndentation(

        string $string, int $indentLen, string $indentChar,

        bool $newlineAtStart, bool $newlineAtEnd, array $attributes

    ) {

        if ($indentLen === 0) {

            return $string;

        }

        $start = $newlineAtStart ? '(?:(?<=\n)|\A)' : '(?<=\n)';

        $end = $newlineAtEnd ? '(?:(?=[\r\n])|\z)' : '(?=[\r\n])';

        $regex = '/' . $start . '([ \t]*)(' . $end . ')?/';

        return preg_replace_callback(

            $regex,

            function ($matches) use ($indentLen, $indentChar, $attributes) {

                $prefix = substr($matches[1], 0, $indentLen);

                if (false !== strpos($prefix, $indentChar === " " ? "\t" : " ")) {

                    $this->emitError(new Error(

                        'Invalid indentation - tabs and spaces cannot be mixed', $attributes

                    ));

                } elseif (strlen($prefix) < $indentLen && !isset($matches[2])) {

                    $this->emitError(new Error(

                        'Invalid body indentation level ' .

                        '(expecting an indentation level of at least ' . $indentLen . ')',

                        $attributes

                    ));

                }

                return substr($matches[0], strlen($prefix));

            },

            $string

        );

    }

    protected function parseDocString(

        string $startToken, $contents, string $endToken,

        array $attributes, array $endTokenAttributes, bool $parseUnicodeEscape

    ) {

        $kind = strpos($startToken, "'") === false

            ? String_::KIND_HEREDOC : String_::KIND_NOWDOC;

        $regex = '/\A[bB]?<<<[ \t]*[\'"]?([a-zA-Z_\x7f-\xff][a-zA-Z0-9_\x7f-\xff]*)[\'"]?(?:\r\n|\n|\r)\z/';

        $result = preg_match($regex, $startToken, $matches);

        assert($result === 1);

        $label = $matches[1];

        $result = preg_match('/\A[ \t]*/', $endToken, $matches);

        assert($result === 1);

        $indentation = $matches[0];

        $attributes['kind'] = $kind;

        $attributes['docLabel'] = $label;

        $attributes['docIndentation'] = $indentation;

        $indentHasSpaces = false !== strpos($indentation, " ");

        $indentHasTabs = false !== strpos($indentation, "\t");

        if ($indentHasSpaces && $indentHasTabs) {

            $this->emitError(new Error(

                'Invalid indentation - tabs and spaces cannot be mixed',

                $endTokenAttributes

            ));

            // Proceed processing as if this doc string is not indented

            $indentation = '';

        }

        $indentLen = \strlen($indentation);

        $indentChar = $indentHasSpaces ? " " : "\t";

        if (\is_string($contents)) {

            if ($contents === '') {

                return new String_('', $attributes);

            }

            $contents = $this->stripIndentation(

                $contents, $indentLen, $indentChar, true, true, $attributes

            );

            $contents = preg_replace('~(\r\n|\n|\r)\z~', '', $contents);

            if ($kind === String_::KIND_HEREDOC) {

                $contents = String_::parseEscapeSequences($contents, null, $parseUnicodeEscape);

            }

            return new String_($contents, $attributes);

        } else {

            assert(count($contents) > 0);

            if (!$contents[0] instanceof Node\Scalar\EncapsedStringPart) {

                // If there is no leading encapsed string part, pretend there is an empty one

                $this->stripIndentation(

                    '', $indentLen, $indentChar, true, false, $contents[0]->getAttributes()

                );

            }

            $newContents = [];

            foreach ($contents as $i => $part) {

                if ($part instanceof Node\Scalar\EncapsedStringPart) {

                    $isLast = $i === \count($contents) - 1;

                    $part->value = $this->stripIndentation(

                        $part->value, $indentLen, $indentChar,

                        $i === 0, $isLast, $part->getAttributes()

                    );

                    $part->value = String_::parseEscapeSequences($part->value, null, $parseUnicodeEscape);

                    if ($isLast) {

                        $part->value = preg_replace('~(\r\n|\n|\r)\z~', '', $part->value);

                    }

                    if ('' === $part->value) {

                        continue;

                    }

                }

                $newContents[] = $part;

            }

            return new Encapsed($newContents, $attributes);

        }

    }

    /**

     * Create attributes for a zero-length common-capturing nop.

     *

     * @param Comment[] $comments

     * @return array

     */

    protected function createCommentNopAttributes(array $comments) {

        $comment = $comments[count($comments) - 1];

        $commentEndLine = $comment->getEndLine();

        $commentEndFilePos = $comment->getEndFilePos();

        $commentEndTokenPos = $comment->getEndTokenPos();

        $attributes = ['comments' => $comments];

        if (-1 !== $commentEndLine) {

            $attributes['startLine'] = $commentEndLine;

            $attributes['endLine'] = $commentEndLine;

        }

        if (-1 !== $commentEndFilePos) {

            $attributes['startFilePos'] = $commentEndFilePos + 1;

            $attributes['endFilePos'] = $commentEndFilePos;

        }

        if (-1 !== $commentEndTokenPos) {

            $attributes['startTokenPos'] = $commentEndTokenPos + 1;

            $attributes['endTokenPos'] = $commentEndTokenPos;

        }

        return $attributes;

    }

    /** @param ElseIf_|Else_ $node */

    protected function fixupAlternativeElse($node) {

        // Make sure a trailing nop statement carrying comments is part of the node.

        $numStmts = \count($node->stmts);

        if ($numStmts !== 0 && $node->stmts[$numStmts - 1] instanceof Nop) {

            $nopAttrs = $node->stmts[$numStmts - 1]->getAttributes();

            if (isset($nopAttrs['endLine'])) {

                $node->setAttribute('endLine', $nopAttrs['endLine']);

            }

            if (isset($nopAttrs['endFilePos'])) {

                $node->setAttribute('endFilePos', $nopAttrs['endFilePos']);

            }

            if (isset($nopAttrs['endTokenPos'])) {

                $node->setAttribute('endTokenPos', $nopAttrs['endTokenPos']);

            }

        }

    }

    protected function checkClassModifier($a, $b, $modifierPos) {

        try {

            Class_::verifyClassModifier($a, $b);

        } catch (Error $error) {

            $error->setAttributes($this->getAttributesAt($modifierPos));

            $this->emitError($error);

        }

    }

    protected function checkModifier($a, $b, $modifierPos) {

        // Jumping through some hoops here because verifyModifier() is also used elsewhere

        try {

            Class_::verifyModifier($a, $b);

        } catch (Error $error) {

            $error->setAttributes($this->getAttributesAt($modifierPos));

            $this->emitError($error);

        }

    }

    protected function checkParam(Param $node) {

        if ($node->variadic && null !== $node->default) {

            $this->emitError(new Error(

                'Variadic parameter cannot have a default value',

                $node->default->getAttributes()

            ));

        }

    }

    protected function checkTryCatch(TryCatch $node) {

        if (empty($node->catches) && null === $node->finally) {

            $this->emitError(new Error(

                'Cannot use try without catch or finally', $node->getAttributes()

            ));

        }

    }

    protected function checkNamespace(Namespace_ $node) {

        if (null !== $node->stmts) {

            foreach ($node->stmts as $stmt) {

                if ($stmt instanceof Namespace_) {

                    $this->emitError(new Error(

                        'Namespace declarations cannot be nested', $stmt->getAttributes()

                    ));

                }

            }

        }

    }

    private function checkClassName($name, $namePos) {

        if (null !== $name && $name->isSpecialClassName()) {

            $this->emitError(new Error(

                sprintf('Cannot use \'%s\' as class name as it is reserved', $name),

                $this->getAttributesAt($namePos)

            ));

        }

    }

    private function checkImplementedInterfaces(array $interfaces) {

        foreach ($interfaces as $interface) {

            if ($interface->isSpecialClassName()) {

                $this->emitError(new Error(

                    sprintf('Cannot use \'%s\' as interface name as it is reserved', $interface),

                    $interface->getAttributes()

                ));

            }

        }

    }

    protected function checkClass(Class_ $node, $namePos) {

        $this->checkClassName($node->name, $namePos);

        if ($node->extends && $node->extends->isSpecialClassName()) {

            $this->emitError(new Error(

                sprintf('Cannot use \'%s\' as class name as it is reserved', $node->extends),

                $node->extends->getAttributes()

            ));

        }

        $this->checkImplementedInterfaces($node->implements);

    }

    protected function checkInterface(Interface_ $node, $namePos) {

        $this->checkClassName($node->name, $namePos);

        $this->checkImplementedInterfaces($node->extends);

    }

    protected function checkEnum(Enum_ $node, $namePos) {

        $this->checkClassName($node->name, $namePos);

        $this->checkImplementedInterfaces($node->implements);

    }

    protected function checkClassMethod(ClassMethod $node, $modifierPos) {

        if ($node->flags & Class_::MODIFIER_STATIC) {

            switch ($node->name->toLowerString()) {

                case '__construct':

                    $this->emitError(new Error(

                        sprintf('Constructor %s() cannot be static', $node->name),

                        $this->getAttributesAt($modifierPos)));

                    break;

                case '__destruct':