[Proposal] Eloquent Collections functional enhancements

[wishfoundry]

Propose to add the following interface to Collection class

/**
 * @method each()
 * @method filter()
 * @method slice()
 * @method sort()
 * @method hasAny()
 * @method any()
 */

This should allow for easier manipulation of collections with closures

These functions are well known and there use should be reasonably easy to guess. An example implementation might look like the following(obviously will need to be adjusted for Laravel coding standards if approved to move forward)

<?php namespace Illuminate\Database\Eloquent;

class Collection{ use FunctionalCollectionsTrait; }

trait FunctionalCollectionsTrait
{

    /**
     * Run a function over every item
     *
     * @param  Closure  $closure
     * @return bool
     */

    public function each(Closure $closure)
    {
        $this->items = array_map($closure, $this->items);
    }

    /**
     * Filter items in collection with closures
     * (keep if return true, delete if return false)
     *
     * @param  Closure  $closure
     * @return void
     */

    public function filter(Closure $closure)
    {
        $this->items =  array_filter($this->items, $closure);
    }

    /**
     * @param int $offset
     * @param int $length
     */
    public  function slice($offset, $length = 0)
    {
        if($length == 0)
            $this->items = array_slice($this->items, $offset);
        else
            $this->items = array_slice($this->items, $offset, $length);
    }


    /**
     * Sort collection by the value returned from the closure
     *
     * @param Closure $closure
     * @param string  $direction
     *
     * @return void
     */
    public function sort(Closure $closure, $direction = 'ASC')
    {
        foreach($this->items as $item)
        {
            $key = $closure($item);
            $sortable[$key] = $item;
        }
        $direction = (strtolower($direction) == 'desc') ? SORT_DESC : SORT_ASC;
        if ($direction == SORT_ASC) ksort($sortable);
        else krsort($sortable);

        $this->items = array_values($sortable);
    }

    /**
     * Check if any item matches a truth test
     *
     * @param Closure $closure
     *
     * @return bool
     */
    public function hasAny(Closure $closure)
    {
       foreach($this->items as $item)
       {
           if($closure($item)) return true;
       }
       return false;
    }

    /**
     * Determine if the collection is empty or not.
     *
     * @return bool
     */
    public function isEmpty()
    {
        return empty($this->items);
    }

}

[taylorotwell]

Good ideas. Will look at implementing them soon.

[jasonlewis]

Very nice, I like it.

+1

[bencorlett]

@taylorotwell Maybe can you make an interface in illuminate/support which has these methods? would be pretty cool to use throughout :)

[daylerees]

A huge +1 to this, a very clean way to avoid a ton of ugly array methods and loops.

[johnnncodes]

+1 Nice nice!

[Anahkiasen]

A lot of the methods that could be really useful for collections can be found in my Underscore package if you want ideas or if this pull is rejected.

[daylerees]

Hi @Anahkiasen I was talking to Taylor the other evening about the possibility of this. We will see what happens :) thanks for your work on that!

[taylorotwell]

Implemented each, filter, and isEmpty.

[kaning]

Should the collection be mutated?