case classes and simple pattern matching
After working for some time with Scala I've realised that I extremely lack having `case` classes (https://docs.scala-lang.org/tour/case-classes.html) and pattern matching in PHP:
You can write some example code:
```php
// you define a case class
case class WithdrawalPolicy(float $fee, bool $daily) // instances of case classes are immutable objects that are compared by state
{
// ... probably other methods (but usually they don't have any though)
}
// which is equivalent to
class WithdrawalPolicy
{
immutable protected $feeRate; /* @var float $feeRate */
immutable protected $daily; /* @var bool $daily */
public function __construct(float $feeRate, bool $daily) {
$this->_feeRate = $feeRate;
$this->_daily = $daily;
}
// some magic methods for accessing $feeRate, $daily
// also we get == and != operators for free that compare the state
}
// following creation and usage:
$policy = WithdrawalPolicy($feeRate=0.12, $daily=true);
echo $policy->feeRate;
echo $policy->daily;
// and the best part is pattern matching
$fee = $policy match {
case WithdrawalPolicy(_, true) => 0.0023; // do smth with daily policies
case WithdrawalPolicy(rate, _) => rate * 0.98; // whether daily or not, do smth with feeRate
}
```
They come in handy in projects with a lot of DTOs, ValueObjects and innerDSL concepts.