Specification Tree vs Iterable approach

AndSpecification.php

<?php

class AndSpecification extends Specification
{
    public function __construct(
        private SpecificationInterface $left,
        private SpecificationInterface $right,
    ) {
    }

    public function isSatisfiedBy(object $candidate): bool
    {
        return $this->left->isSatisfiedBy($candidate) && $this->right->isSatisfiedBy($candidate);
    }
}

Guard.php

<?php

class Guard
{
    /**
     * @param iterable<Specification> $requirements
     */
    public function __construct(private iterable $requirements)
    {
    }

    public function isSatisfiedByIterableApproach(OrderInterface $order): bool
    {
        // Iterable approach
        foreach ($this->requirements as $requirement) {
            if (!$requirement->isSatisfiedBy($order)) {
                return false;
            }
        }

        return true;
    }

    public function isSatisfiedByDynamicTreeApproach(OrderInterface $order): bool
    {
        // Dynamic Tree approach
        $first = array_shift($this->requirements);

        foreach ($this->requirements as $requirement) {
           $first = $first->and($requirement);
        }

        return $first->isSatisfiedBy($order);
    }

    public function isSatisfiedByStaticApproach(OrderInterface $order): bool
    {
        // Static approach
        $requirements = new RequiredNonEmptyCartSpecification();
        $requirements
            ->and(new RequiredBillingAddressSpecification())
            ->and(new RequiredShippingSpecification())
            ->and(new RequiredPaymentSpecification())
        ;

        return $requirements->isSatisfiedBy($order);
    }
}

OrSpecification.php

<?php

class OrSpecification extends Specification
{
    public function __construct(
        private SpecificationInterface $left,
        private SpecificationInterface $right,
    ) {
    }

    public function isSatisfiedBy(object $candidate): bool
    {
        return $this->left->isSatisfiedBy($candidate) || $this->right->isSatisfiedBy($candidate);
    }
}

Specification.php

<?php

abstract class Specification
{
    public abstract function isSatisfiedBy(object $candidate): bool;
    
    public function and(SpecificationInterface $specification): SpecificationInterface
    {
        return new AndSpecification($this, $specification);
    }
    
    public function or(SpecificationInterface $specification): SpecificationInterface
    {
        return new OrSpecification($this, $specification);
    }
}