spindle / spindle-collection

    /**

     * @return int|float

     */

    public function sum()

    {

        $ops = $this->ops;

        $before = '$_result = 0;';

        $ops[] = '    $_result += $_;';

        return self::evaluate($this->seed, $this->vars, $this->compile($ops), $before, '');

    }

    /**

     * @return int|float

    /**

     * @return int|float

     */

    public function product()

    {

        $ops = $this->ops;

        $before = '$_result = 1;';

        $ops[] = '    $_result *= $_;';

        return self::evaluate($this->seed, $this->vars, $this->compile($ops), $before, '');

    }

    /**

     * @return \Spindle\Collection (new instance)

    /**

     * @return \Generator

     */

    public function getIterator()

    {

        $ops = $this->ops;

        $ops[] = 'yield $_key => $_;';

        $gen = self::evaluate(

            $this->seed,

            $this->vars,

            $this->compile($ops),

            '$_result = static function() use($_seed){',

            '};'

        );

        return $gen();

    }

    /**

     * @return array