Consider adding Bidirectional Map

[evpav]

https://en.wikipedia.org/wiki/Bidirectional_map

[rtheunissen]

You can create one very easily.

class BiMap 
{
    protected $map;

    public function __construct()
    {
        $this->map = new \Ds\Map();
    }

    public function put($key, $value) 
    {
        $this->map->put($key, $value);
        $this->map->put($value, $key);
    }

    public function get($key)
    {
        return $this->map->get($key);
    }
}

Or am I missing something here?

[rtheunissen]

The ideal is to provide fundamental structures that allow for easy composition.

[evpav]

Or am I missing something here?

length, keys, values would be 2x; few corner cases and specifics; room for memory optimization (2 maps/tree).

The ideal is to provide fundamental structures that allow for easy composition.

I'm ok with that, just thought it would be convenient for users to have a good implementation(s) of the bimap here, because I haven't seen one for php yet.

[rtheunissen]

Good points, especially around length being 2x. Could you compose using 2 maps instead and override length? What would length return anyway; max(k.length, v.length)?

I'll take a closer look at BiMaps because I don't know much about them.

[rtheunissen]

I am not convinced of the practical benefits at this stage, might reconsider later on.