Doctrine\Common\Collections\Expr\ClosureExpressionVisitor::walkComparison PHP Method

    public function walkComparison(Comparison $comparison)
    {
        $field = $comparison->getField();
        $value = $comparison->getValue()->getValue();
        // shortcut for walkValue()
        switch ($comparison->getOperator()) {
            case Comparison::EQ:
                return function ($object) use($field, $value) {
                    return ClosureExpressionVisitor::getObjectFieldValue($object, $field) === $value;
                };
            case Comparison::NEQ:
                return function ($object) use($field, $value) {
                    return ClosureExpressionVisitor::getObjectFieldValue($object, $field) !== $value;
                };
            case Comparison::LT:
                return function ($object) use($field, $value) {
                    return ClosureExpressionVisitor::getObjectFieldValue($object, $field) < $value;
                };
            case Comparison::LTE:
                return function ($object) use($field, $value) {
                    return ClosureExpressionVisitor::getObjectFieldValue($object, $field) <= $value;
                };
            case Comparison::GT:
                return function ($object) use($field, $value) {
                    return ClosureExpressionVisitor::getObjectFieldValue($object, $field) > $value;
                };
            case Comparison::GTE:
                return function ($object) use($field, $value) {
                    return ClosureExpressionVisitor::getObjectFieldValue($object, $field) >= $value;
                };
            case Comparison::IN:
                return function ($object) use($field, $value) {
                    return in_array(ClosureExpressionVisitor::getObjectFieldValue($object, $field), $value);
                };
            case Comparison::NIN:
                return function ($object) use($field, $value) {
                    return !in_array(ClosureExpressionVisitor::getObjectFieldValue($object, $field), $value);
                };
            case Comparison::CONTAINS:
                return function ($object) use($field, $value) {
                    return false !== strpos(ClosureExpressionVisitor::getObjectFieldValue($object, $field), $value);
                };
            case Comparison::MEMBER_OF:
                return function ($object) use($field, $value) {
                    $fieldValues = ClosureExpressionVisitor::getObjectFieldValue($object, $field);
                    if (!is_array($fieldValues)) {
                        $fieldValues = iterator_to_array($fieldValues);
                    }
                    return in_array($value, $fieldValues);
                };
            case Comparison::STARTS_WITH:
                return function ($object) use($field, $value) {
                    return 0 === strpos(ClosureExpressionVisitor::getObjectFieldValue($object, $field), $value);
                };
            case Comparison::ENDS_WITH:
                return function ($object) use($field, $value) {
                    return $value === substr(ClosureExpressionVisitor::getObjectFieldValue($object, $field), -strlen($value));
                };
            default:
                throw new \RuntimeException("Unknown comparison operator: " . $comparison->getOperator());
        }
    }

 public function testArrayComparison()
 {
     $closure = $this->visitor->walkComparison($this->builder->eq("foo", 42));
     $this->assertTrue($closure(array('foo' => 42)));
 }