datastructures interfaces

<?php
use Eos\Datastructures\Immutable;
use Eos\Datastructures\Struct;

class Rectangle extends Struct implements Immutable {
  public $x;
  public $y;
  public $height;
  public $width;
}

$rect = new Rectangle(['x' => 5, 'y' => 6, 'height' => 56, 'width' => 19]);

$rect->x = 5; // will throw ImmutableException

So you're talking overloading objects, rather than extending? Basically, just to create very lightweight value objects? In which case yeah, I'd be happy enough for that. Progress is progress :) Thanks

On the with() method on the immutable structs, would that always return a new struct? If you're chaining these then you'd be returning a new struct just to throw them away? Would they be built by reference, or would they be new and independent?

Presumably each with() call would return a new struct instance, but with PHP's copy-on-write the memory impact should be minimal. That's how PSR-7 works, and the initial benchmarks said it was cheap enough to do.

And I guess now I see the point of nullables, since without them a struct would only sort of function. Unless we allowed a property to have a default value defined, so even $r = Rectangle{}; would give a valid set of values. Honestly I think I prefer that to nullable, as nulls are nothing but a source of pain and suffering.

That is, you'd have:

struct Rectangle {
  int $x = 0;
  int $y = 0;
  float $width = 0;
  float $height = 0;
}

$r = Rectangle{};
print $r->x; // prints 0.

That way there's still never a null.