PHPSA\Compiler\Expression

Complexity

Total Complexity

152

Size/Duplication

Total Lines	712
Duplicated Lines	0 %

Coupling/Cohesion

Components	1
Dependencies	82

Test Coverage

Coverage

65.16%

Importance

Changes

0

14 Methods

Rating	Name	Duplication	Size	Complexity
A	__construct()	0	5	1
B	passSymbolByRef()	0	39	5
A	passExprVariable()	0	16	2
A	constFetch()	0	17	4
D	factory()	0	166	60
D	compile()	0	84	23
C	passProperty()	0	60	11
A	getFullyQualifiedNodeName()	0	6	1
C	getNodeName()	0	36	7
C	passPropertyFetch()	0	41	7
B	passConstFetch()	0	22	4
A	declareVariable()	0	10	2
D	passSymbol()	0	91	16
D	getArray()	0	32	9

<?php
/**
 * @author Patsura Dmitry https://github.com/ovr <talk@dmtry.me>
 */

namespace PHPSA\Compiler;

use InvalidArgumentException;
use PHPSA\Check;
use PHPSA\CompiledExpression;
use PHPSA\Compiler\Event\ExpressionBeforeCompile;
use PHPSA\Context;
use PhpParser\Node;
use PHPSA\Definition\ClassDefinition;
use PHPSA\Exception\RuntimeException;
use PHPSA\Variable;
use PHPSA\Compiler\Expression\AbstractExpressionCompiler;
use Webiny\Component\EventManager\EventManager;

class Expression

This class has a complexity of 152 which exceeds the configured maximum of 50.

{
    /**
     * @var Context
     */
    protected $context;

    /**
     * @var EventManager
     */
    protected $eventManager;

    /**
     * @param Context $context
     */
    public function __construct(Context $context, EventManager $eventManager)
    {
        $this->context = $context;
        $this->eventManager = $eventManager;
    }

    /**
     * @param $expr
     * @return ExpressionCompilerInterface|AbstractExpressionCompiler
     */
    protected function factory($expr)
    {
        switch (get_class($expr)) {
            /**
             * Call(s)
             */
            case Node\Expr\MethodCall::class:
                return new Expression\MethodCall();
            case Node\Expr\FuncCall::class:
                return new Expression\FunctionCall();
            case Node\Expr\StaticCall::class:
                return new Expression\StaticCall();
            /**
             * Operators
             */
            case Node\Expr\New_::class:
                return new Expression\Operators\NewOp();
            case Node\Expr\Instanceof_::class:
                return new Expression\Operators\InstanceOfOp();
            /**
             * AssignOp
             */
            case Node\Expr\AssignOp\Pow::class:
                return new Expression\AssignOp\Pow();
            case Node\Expr\AssignOp\Plus::class:
                return new Expression\AssignOp\Plus();
            case Node\Expr\AssignOp\Minus::class:
                return new Expression\AssignOp\Minus();
            case Node\Expr\AssignOp\Mul::class:
                return new Expression\AssignOp\Mul();
            case Node\Expr\AssignOp\Div::class:
                return new Expression\AssignOp\Div();
            case Node\Expr\AssignOp\Mod::class:
                return new Expression\AssignOp\Mod();
            case Node\Expr\AssignOp\BitwiseOr::class:
                return new Expression\AssignOp\BitwiseOr();
            case Node\Expr\AssignOp\BitwiseAnd::class:
                return new Expression\AssignOp\BitwiseAnd();
            case Node\Expr\AssignOp\BitwiseXor::class:
                return new Expression\AssignOp\BitwiseXor();
            case Node\Expr\AssignOp\Concat::class:
                return new Expression\AssignOp\Concat();
            case Node\Expr\AssignOp\ShiftLeft::class:
                return new Expression\AssignOp\ShiftLeft();
            case Node\Expr\AssignOp\ShiftRight::class:
                return new Expression\AssignOp\ShiftRight();

            /**
             * BinaryOp
             */
            case Node\Expr\BinaryOp\Identical::class:
                return new Expression\BinaryOp\Identical();
            case Node\Expr\BinaryOp\Concat::class:
                return new Expression\Operators\Concat();
            case Node\Expr\BinaryOp\NotIdentical::class:
                return new Expression\BinaryOp\NotIdentical();
            case Node\Expr\BinaryOp\Equal::class:
                return new Expression\BinaryOp\Equal();
            case Node\Expr\BinaryOp\NotEqual::class:
                return new Expression\BinaryOp\NotEqual();
            case Node\Expr\BinaryOp\Spaceship::class:
                return new Expression\BinaryOp\SpaceShip();
                
            /**
             * @link http://php.net/manual/en/language.operators.increment.php
             */
            case Node\Expr\PostInc::class:
                return new Expression\Operators\PostInc();
            case Node\Expr\PostDec::class:
                return new Expression\Operators\PostDec();
            case Node\Expr\PreInc::class:
                return new Expression\Operators\PreInc();
            case Node\Expr\PreDec::class:
                return new Expression\Operators\PreDec();
            /**
             * Arithmetical
             */
            case Node\Expr\BinaryOp\Div::class:
                return new Expression\Operators\Arithmetical\Div();
            case Node\Expr\BinaryOp\Plus::class:
                return new Expression\Operators\Arithmetical\Plus();
            case Node\Expr\BinaryOp\Minus::class:
                return new Expression\Operators\Arithmetical\Minus();
            case Node\Expr\BinaryOp\Mul::class:
                return new Expression\Operators\Arithmetical\Mul();
            case Node\Expr\BinaryOp\Mod::class:
                return new Expression\Operators\Arithmetical\Mod();
            case Node\Expr\BinaryOp\Pow::class:
                return new Expression\Operators\Arithmetical\Pow();

            /**
             * Bitwise
             * @link http://php.net/manual/ru/language.operators.bitwise.php
             */
            case Node\Expr\BinaryOp\BitwiseOr::class:
                return new Expression\Operators\Bitwise\BitwiseOr();
            case Node\Expr\BinaryOp\BitwiseXor::class:
                return new Expression\Operators\Bitwise\BitwiseXor();
            case Node\Expr\BinaryOp\BitwiseAnd::class:
                return new Expression\Operators\Bitwise\BitwiseAnd();
            case Node\Expr\BinaryOp\ShiftRight::class:
                return new Expression\Operators\Bitwise\ShiftRight();
            case Node\Expr\BinaryOp\ShiftLeft::class:
                return new Expression\Operators\Bitwise\ShiftLeft();
            case Node\Expr\BitwiseNot::class:
                return new Expression\Operators\Bitwise\BitwiseNot();
            /**
             * Logical
             */
            case Node\Expr\BinaryOp\BooleanOr::class:
                return new Expression\Operators\Logical\BooleanOr();
            case Node\Expr\BinaryOp\BooleanAnd::class:
                return new Expression\Operators\Logical\BooleanAnd();
            case Node\Expr\BooleanNot::class:
                return new Expression\Operators\Logical\BooleanNot();
            case Node\Expr\BinaryOp\LogicalAnd::class:
                return new Expression\Operators\Logical\LogicalAnd();
            case Node\Expr\BinaryOp\LogicalOr::class:
                return new Expression\Operators\Logical\LogicalOr();
            case Node\Expr\BinaryOp\LogicalXor::class:
                return new Expression\Operators\Logical\LogicalXor();

            /**
             * Comparison
             */
            case Node\Expr\BinaryOp\Greater::class:
                return new Expression\Operators\Comparison\Greater();
            case Node\Expr\BinaryOp\GreaterOrEqual::class:
                return new Expression\Operators\Comparison\GreaterOrEqual();
            case Node\Expr\BinaryOp\Smaller::class:
                return new Expression\Operators\Comparison\Smaller();
            case Node\Expr\BinaryOp\SmallerOrEqual::class:
                return new Expression\Operators\Comparison\SmallerOrEqual();

            /**
             * Casts
             */
            case Node\Expr\Cast\Array_::class:
                return new Expression\Casts\ArrayCast();
            case Node\Expr\Cast\Bool_::class:
                return new Expression\Casts\BoolCast();
            case Node\Expr\Cast\Int_::class:
                return new Expression\Casts\IntCast();
            case Node\Expr\Cast\Double::class:
                return new Expression\Casts\DoubleCast();
            case Node\Expr\Cast\Object_::class:
                return new Expression\Casts\ObjectCast();
            case Node\Expr\Cast\String_::class:
                return new Expression\Casts\StringCast();
            case Node\Expr\Cast\Unset_::class:
                return new Expression\Casts\UnsetCast();


            /**
             * Other
             */
            case Node\Expr\Closure::class:
                return new Expression\Closure();
            case Node\Expr\UnaryMinus::class:
                return new Expression\Operators\UnaryMinus();
            case Node\Expr\UnaryPlus::class:
                return new Expression\Operators\UnaryPlus();
        }

        return false;
    }

    /**
     * @param object|string $expr
     * @return CompiledExpression
     */
    public function compile($expr)

This operation has 544 execution paths which exceeds the configured maximum of 200.

    {
        if (is_string($expr)) {
            return new CompiledExpression(CompiledExpression::STRING, $expr);
        }

        if (is_null($expr)) {
            return new CompiledExpression(CompiledExpression::NULL);
        }

        if (!is_object($expr)) {
            throw new InvalidArgumentException('$expr must be string/object/null');
        }

        $this->eventManager->fire(
            ExpressionBeforeCompile::EVENT_NAME,
            new ExpressionBeforeCompile(
                $expr,
                $this->context
            )
        );

        $className = get_class($expr);
        switch ($className) {
            case Node\Arg::class:
                /**
                 * @todo Better compile
                 */
                return $this->compile($expr->value);
            case Node\Expr\PropertyFetch::class:
                return $this->passPropertyFetch($expr);
            case Node\Stmt\Property::class:
                return $this->passProperty($expr);
            case Node\Expr\ClassConstFetch::class:
                return $this->passConstFetch($expr);
            case Node\Expr\Assign::class:
                return $this->passSymbol($expr);
            case Node\Expr\AssignRef::class:
                return $this->passSymbolByRef($expr);
            case Node\Expr\Variable::class:
                return $this->passExprVariable($expr);

            /**
             * Expressions
             */
            case Node\Expr\Array_::class:
                return $this->getArray($expr);
            case Node\Expr\ConstFetch::class:
                return $this->constFetch($expr);
            case Node\Name::class:
                return $this->getNodeName($expr);
            case Node\Name\FullyQualified::class:
                return $this->getFullyQualifiedNodeName($expr);

            /**
             * Simple Scalar(s)
             */
            case \PHPSA\Node\Scalar\Nil::class:
                return new CompiledExpression(CompiledExpression::NULL);
            case Node\Scalar\LNumber::class:
                return new CompiledExpression(CompiledExpression::INTEGER, $expr->value);
            case Node\Scalar\DNumber::class:
                return new CompiledExpression(CompiledExpression::DOUBLE, $expr->value);
            case Node\Scalar\String_::class:
                return new CompiledExpression(CompiledExpression::STRING, $expr->value);
            case \PHPSA\Node\Scalar\Boolean::class:
                return new CompiledExpression(CompiledExpression::BOOLEAN, $expr->value);
            case \PHPSA\Node\Scalar\Fake::class:
                return new CompiledExpression($expr->type, $expr->value);
        }

        $expressionCompiler = $this->factory($expr);
        if (!$expressionCompiler) {
            $this->context->debug("Expression compiler is not implemented for {$className}");
            return new CompiledExpression(CompiledExpression::UNIMPLEMENTED);
        }

        $result = $expressionCompiler->pass($expr, $this->context);
        if (!$result instanceof CompiledExpression) {
            throw new RuntimeException('Please return CompiledExpression from ' . get_class($expressionCompiler));
        }

        return $result;
    }

    /**
     * @todo Implement
     *
     * @param Node\Stmt\Property $st
     * @return CompiledExpression
     */
    public function passProperty(Node\Stmt\Property $st)

Avoid variables with short names like $st. Configured minimum length is 3.

    {
        $docBlock = $st->getDocComment();
        if (!$docBlock) {
            $this->context->notice(
                'missing-docblock',
                sprintf('Missing docblock for $%s property', $st->props[0]->name),
                $st
            );

            return new CompiledExpression();
        }

        $phpdoc = new \phpDocumentor\Reflection\DocBlock($docBlock->getText());

        $varTags = $phpdoc->getTagsByName('var');
        if ($varTags) {

The expression $varTags of type phpDocumentor\Reflection\DocBlock\Tag[] is implicitly converted to a boolean; are you sure this is intended? If so, consider using ! empty($expr) instead to make it clear that you intend to check for an array without elements.

            /** @var \phpDocumentor\Reflection\DocBlock\Tag\VarTag $varTag */
            $varTag = current($varTags);

            $typeResolver = new \phpDocumentor\Reflection\TypeResolver();

            try {
                $type = $typeResolver->resolve($varTag->getType());
            } catch (\InvalidArgumentException $e) {
                return new CompiledExpression();
            }

            if ($type) {
                switch (get_class($type)) {
                    case \phpDocumentor\Reflection\Types\Object_::class:
                        return new CompiledExpression(
                            CompiledExpression::OBJECT
                        );
                    case \phpDocumentor\Reflection\Types\Integer::class:
                        return new CompiledExpression(
                            CompiledExpression::INTEGER
                        );
                    case \phpDocumentor\Reflection\Types\String_::class:
                        return new CompiledExpression(
                            CompiledExpression::STRING
                        );
                    case \phpDocumentor\Reflection\Types\Float_::class:
                        return new CompiledExpression(
                            CompiledExpression::DOUBLE
                        );
                    case \phpDocumentor\Reflection\Types\Null_::class:
                        return new CompiledExpression(
                            CompiledExpression::NULL
                        );
                    case \phpDocumentor\Reflection\Types\Boolean::class:
                        return new CompiledExpression(
                            CompiledExpression::BOOLEAN
                        );
                }
            }
        }

        return new CompiledExpression();
    }

    /**
     * @param Node\Expr\Variable $expr
     * @return CompiledExpression
     */
    public function declareVariable(Node\Expr\Variable $expr)
    {
        $variable = $this->context->getSymbol($expr->name);
        if (!$variable) {
            $variable = new Variable($expr->name, null, CompiledExpression::UNKNOWN, $this->context->getCurrentBranch());

It seems like $expr->name can also be of type object<PhpParser\Node\Expr>; however, PHPSA\Variable::__construct() does only seem to accept string, maybe add an additional type check?

            $this->context->addVariable($variable);
        }

        return new CompiledExpression($variable->getType(), $variable->getValue(), $variable);
    }

    /**
     * @param Node\Name\FullyQualified $expr
     * @return CompiledExpression
     */
    public function getFullyQualifiedNodeName(Node\Name\FullyQualified $expr)
    {
        $this->context->debug('Unimplemented FullyQualified', $expr);

        return new CompiledExpression;
    }

    /**
     * @param Node\Name $expr
     * @return CompiledExpression
     */
    public function getNodeName(Node\Name $expr)
    {
        $nodeString = $expr->toString();
        if ($nodeString === 'null') {
            return new CompiledExpression(CompiledExpression::NULL);
        }

        if (in_array($nodeString, ['parent'], true)) {
            /** @var ClassDefinition $scope */
            $scope = $this->context->scope;
            assert($scope instanceof ClassDefinition);

            if ($scope->getExtendsClass()) {

The expression $scope->getExtendsClass() of type string|null is loosely compared to true; this is ambiguous if the string can be empty. You might want to explicitly use !== null instead.

                $definition = $scope->getExtendsClassDefinition();
                if ($definition) {
                    return new CompiledExpression(CompiledExpression::OBJECT, $definition);
                }
            } else {
                $this->context->notice(
                    'no-parent',
                    'Cannot access parent:: when current class scope has no parent',
                    $expr
                );
            }
        }

        if (in_array($nodeString, ['self', 'static'], true)) {
            return CompiledExpression::fromZvalValue($this->context->scope);
        }

        if (defined($nodeString)) {
            return CompiledExpression::fromZvalValue(constant($expr));
        }

        return new CompiledExpression(CompiledExpression::STRING, $expr->toString());
    }

    /**
     * @param Node\Expr\PropertyFetch $expr
     * @return CompiledExpression
     */
    protected function passPropertyFetch(Node\Expr\PropertyFetch $expr)
    {
        $propertNameCE = $this->compile($expr->name);

        $scopeExpression = $this->compile($expr->var);
        if ($scopeExpression->isObject()) {
            $scopeExpressionValue = $scopeExpression->getValue();
            if ($scopeExpressionValue instanceof ClassDefinition) {
                $propertyName = $propertNameCE->isString() ? $propertNameCE->getValue() : false;
                if ($propertyName) {
                    if ($scopeExpressionValue->hasProperty($propertyName, true)) {
                        $property = $scopeExpressionValue->getProperty($propertyName, true);
                        return $this->compile($property);
                    } else {
                        $this->context->notice(
                            'undefined-property',
                            sprintf(
                                'Property %s does not exist in %s scope',
                                $propertyName,
                                $scopeExpressionValue->getName()
                            ),
                            $expr
                        );
                    }
                }
            }

            return new CompiledExpression(CompiledExpression::UNKNOWN);
        } elseif (!$scopeExpression->canBeObject()) {
            return new CompiledExpression(CompiledExpression::UNKNOWN);
        }

        $this->context->notice(
            'property-fetch-on-non-object',
            "It's not possible to fetch property on not object",
            $expr,
            Check::CHECK_BETA
        );

        return new CompiledExpression(CompiledExpression::UNKNOWN);
    }

    /**
     * @param Node\Expr\ClassConstFetch $expr
     * @return CompiledExpression
     */
    protected function passConstFetch(Node\Expr\ClassConstFetch $expr)
    {
        $leftCE = $this->compile($expr->class);
        if ($leftCE->isObject()) {
            $leftCEValue = $leftCE->getValue();
            if ($leftCEValue instanceof ClassDefinition) {
                if (!$leftCEValue->hasConst($expr->name, true)) {
                    $this->context->notice(
                        'undefined-const',
                        sprintf('Constant %s does not exist in %s scope', $expr->name, $expr->class),
                        $expr
                    );
                    return new CompiledExpression(CompiledExpression::UNKNOWN);
                }

                return new CompiledExpression();
            }
        }

        $this->context->debug('Unknown const fetch', $expr);
        return new CompiledExpression();
    }

    /**
     * @param Node\Expr\Assign $expr
     * @return CompiledExpression
     */
    protected function passSymbol(Node\Expr\Assign $expr)

This operation has 240 execution paths which exceeds the configured maximum of 200.

    {
        $compiledExpression = $this->compile($expr->expr);

        if ($expr->var instanceof Node\Expr\List_) {
            $isCorrectType = false;

            switch ($compiledExpression->getType()) {
                case CompiledExpression::ARR:
                    $isCorrectType = true;
                    break;
            }

            if ($expr->var->vars) {

The expression $expr->var->vars of type PhpParser\Node\Expr[] is implicitly converted to a boolean; are you sure this is intended? If so, consider using ! empty($expr) instead to make it clear that you intend to check for an array without elements.

                foreach ($expr->var->vars as $key => $var) {
                    if ($var instanceof Node\Expr\Variable) {
                        $name = $expr->var->name;

The property name does not seem to exist in PhpParser\Node\Expr\List_.

                        $symbol = $this->context->getSymbol($name);
                        if (!$symbol) {
                            $symbol = new Variable(
                                $name,

It seems like $name defined by $expr->var->name on line 528 can also be of type object<PhpParser\Node\Expr>; however, PHPSA\Variable::__construct() does only seem to accept string, maybe add an additional type check?

                                null,
                                CompiledExpression::UNKNOWN,
                                $this->context->getCurrentBranch()
                            );
                            $this->context->addVariable($symbol);
                        }

                        if (!$isCorrectType) {
                            $symbol->modify(CompiledExpression::NULL, null);
                        }

                        $symbol->incSets();
                    }
                }
            }

            return new CompiledExpression();
        }


        if ($expr->var instanceof Node\Expr\Variable) {
            $compiledExpressionName = $this->compile($expr->var->name);

The variable name $compiledExpressionName exceeds the maximum configured length of 20.

            switch ($compiledExpressionName->getType()) {
                case CompiledExpression::STRING:
                    break;
                default:
                    $this->context->debug('Unexpected type of Variable name after compile');
                    return new CompiledExpression();
            }

            $symbol = $this->context->getSymbol($compiledExpressionName->getValue());
            if ($symbol) {
                $symbol->modify($compiledExpression->getType(), $compiledExpression->getValue());
                $this->context->modifyReferencedVariables(
                    $symbol,
                    $compiledExpression->getType(),
                    $compiledExpression->getValue()
                );
            } else {
                $symbol = new Variable(
                    $compiledExpressionName->getValue(),
                    $compiledExpression->getValue(),
                    $compiledExpression->getType(),
                    $this->context->getCurrentBranch()
                );
                $this->context->addVariable($symbol);
            }

            $symbol->incSets();
            return $compiledExpression;
        }

        if ($expr->var instanceof Node\Expr\PropertyFetch) {
            $compiledExpression = $this->compile($expr->var->var);
            if ($compiledExpression->getType() == CompiledExpression::OBJECT) {
                $objectDefinition = $compiledExpression->getValue();
                if ($objectDefinition instanceof ClassDefinition) {
                    if (is_string($expr->var->name)) {
                        if ($objectDefinition->hasProperty($expr->var->name)) {
                            return $this->compile($objectDefinition->getProperty($expr->var->name));
                        }
                    }
                }
            }
        }

        $this->context->debug('Unknown how to pass symbol');
        return new CompiledExpression();
    }

    /**
     * @param Node\Expr\AssignRef $expr
     * @return CompiledExpression
     */
    protected function passSymbolByRef(Node\Expr\AssignRef $expr)
    {
        if ($expr->var instanceof Node\Expr\Variable) {
            $name = $expr->var->name;

            $compiledExpression = $this->compile($expr->expr);

            $symbol = $this->context->getSymbol($name);
            if ($symbol) {
                $symbol->modify($compiledExpression->getType(), $compiledExpression->getValue());
            } else {
                $symbol = new Variable(
                    $name,

It seems like $name defined by $expr->var->name on line 611 can also be of type object<PhpParser\Node\Expr>; however, PHPSA\Variable::__construct() does only seem to accept string, maybe add an additional type check?

                    $compiledExpression->getValue(),
                    $compiledExpression->getType(),
                    $this->context->getCurrentBranch()
                );
                $this->context->addVariable($symbol);
            }

            if ($expr->expr instanceof Node\Expr\Variable) {
                $rightVarName = $expr->expr->name;

                $rightSymbol = $this->context->getSymbol($rightVarName);
                if ($rightSymbol) {
                    $rightSymbol->incUse();
                    $symbol->setReferencedTo($rightSymbol);
                } else {
                    $this->context->debug('Cannot fetch variable by name: ' . $rightVarName);
                }
            }

            $symbol->incSets();
            return $compiledExpression;
        }

        $this->context->debug('Unknown how to pass symbol by ref');
        return new CompiledExpression();
    }

    /**
     * @param Node\Expr\Variable $expr
     * @return CompiledExpression
     */
    protected function passExprVariable(Node\Expr\Variable $expr)
    {
        $variable = $this->context->getSymbol($expr->name);
        if ($variable) {
            $variable->incGets();
            return new CompiledExpression($variable->getType(), $variable->getValue(), $variable);
        }

        $this->context->notice(
            'undefined-variable',
            sprintf('You trying to use undefined variable $%s', $expr->name),
            $expr
        );

        return new CompiledExpression();
    }

    /**
     * Compile Array_ expression to CompiledExpression
     *
     * @param Node\Expr\Array_ $expr
     * @return CompiledExpression
     */
    protected function getArray(Node\Expr\Array_ $expr)
    {
        if ($expr->items === []) {
            return new CompiledExpression(CompiledExpression::ARR, []);
        }

        $resultArray = [];

        foreach ($expr->items as $item) {
            $compiledValueResult = $this->compile($item->value);
            if ($item->key) {
                $compiledKeyResult = $this->compile($item->key);
                switch ($compiledKeyResult->getType()) {
                    case CompiledExpression::INTEGER:
                    case CompiledExpression::DOUBLE:
                    case CompiledExpression::BOOLEAN:
                    case CompiledExpression::NULL:
                    case CompiledExpression::STRING:
                        $resultArray[$compiledKeyResult->getValue()] = $compiledValueResult->getValue();
                        break;
                    default:
                        $this->context->debug("Type {$compiledKeyResult->getType()} is not supported for key value");
                        return new CompiledExpression(CompiledExpression::ARR);
                        break;

break is not strictly necessary here and could be removed.

                }
            } else {
                $resultArray[] = $compiledValueResult->getValue();
            }
        }

        return new CompiledExpression(CompiledExpression::ARR, $resultArray);
    }

    /**
     * Convert const fetch expr to CompiledExpression
     *
     * @param Node\Expr\ConstFetch $expr
     * @return CompiledExpression
     */
    protected function constFetch(Node\Expr\ConstFetch $expr)
    {
        if ($expr->name instanceof Node\Name) {
            if ($expr->name->parts[0] === 'true') {
                return new CompiledExpression(CompiledExpression::BOOLEAN, true);
            }

            if ($expr->name->parts[0] === 'false') {
                return new CompiledExpression(CompiledExpression::BOOLEAN, false);
            }
        }

        /**
         * @todo Implement check
         */
        return $this->compile($expr->name);
    }
}