Collection inspiration

[nozavroni]

Here is a list of things from Doctrine's collections classes that I want to implement as well...

• [ ] Collection::__toString()

    /**
     * Returns a string representation of this object.
     *
     * @return string
     */
    public function __toString()
    {
        return __CLASS__ . '@' . spl_object_hash($this);
    }

• [ ] Basic iterator methods and toArray()

/**
     * {@inheritDoc}
     */
    public function toArray()
    {
        return $this->elements;
    }

    /**
     * {@inheritDoc}
     */
    public function first()
    {
        return reset($this->elements);
    }

    /**
     * {@inheritDoc}
     */
    public function last()
    {
        return end($this->elements);
    }

    /**
     * {@inheritDoc}
     */
    public function key()
    {
        return key($this->elements);
    }

    /**
     * {@inheritDoc}
     */
    public function next()
    {
        return next($this->elements);
    }

    /**
     * {@inheritDoc}
     */
    public function current()
    {
        return current($this->elements);
    }

    /**
     * {@inheritDoc}
     */
    public function remove($key)
    {
        if ( ! isset($this->elements[$key]) && ! array_key_exists($key, $this->elements)) {
            return null;
        }

        $removed = $this->elements[$key];
        unset($this->elements[$key]);

        return $removed;
    }

    /**
     * {@inheritDoc}
     */
    public function removeElement($element)
    {
        $key = array_search($element, $this->elements, true);

        if ($key === false) {
            return false;
        }

        unset($this->elements[$key]);

        return true;
    }

• [ ] Contains and exists rather than both wrapped into one

    /**
     * {@inheritDoc}
     */
    public function contains($element)
    {
        return in_array($element, $this->elements, true);
    }

    /**
     * {@inheritDoc}
     */
    public function exists(Closure $p)
    {
        foreach ($this->elements as $key => $element) {
            if ($p($key, $element)) {
                return true;
            }
        }

        return false;
    }

• [ ] indexOf

    /**
     * {@inheritDoc}
     */
    public function indexOf($element)
    {
        return array_search($element, $this->elements, true);
    }

• [ ] getIterator()

    /**
     * Required by interface IteratorAggregate.
     *
     * {@inheritDoc}
     */
    public function getIterator()
    {
        return new ArrayIterator($this->elements);
    }

• [ ] forAll()

    /**
     * {@inheritDoc}
     */
    public function forAll(Closure $p)
    {
        foreach ($this->elements as $key => $element) {
            if ( ! $p($key, $element)) {
                return false;
            }
        }

        return true;
    }

• [ ] partition

    /**
     * {@inheritDoc}
     */
    public function partition(Closure $p)
    {
        $matches = $noMatches = array();

        foreach ($this->elements as $key => $element) {
            if ($p($key, $element)) {
                $matches[$key] = $element;
            } else {
                $noMatches[$key] = $element;
            }
        }

        return array(new static($matches), new static($noMatches));
    }

• [ ] clear

    /**
     * {@inheritDoc}
     */
    public function clear()
    {
        $this->elements = array();
    }

• [ ] slice

    /**
     * {@inheritDoc}
     */
    public function slice($offset, $length = null)
    {
        return array_slice($this->elements, $offset, $length, true);
    }

• [ ] matching (like my where method was)

    /**
     * {@inheritDoc}
     */
    public function matching(Criteria $criteria)
    {
        $expr     = $criteria->getWhereExpression();
        $filtered = $this->elements;

        if ($expr) {
            $visitor  = new ClosureExpressionVisitor();
            $filter   = $visitor->dispatch($expr);
            $filtered = array_filter($filtered, $filter);
        }

        if ($orderings = $criteria->getOrderings()) {
            foreach (array_reverse($orderings) as $field => $ordering) {
                $next = ClosureExpressionVisitor::sortByField($field, $ordering == Criteria::DESC ? -1 : 1);
            }

            uasort($filtered, $next);
        }

        $offset = $criteria->getFirstResult();
        $length = $criteria->getMaxResults();

        if ($offset || $length) {
            $filtered = array_slice($filtered, (int)$offset, $length);
        }

        return new static($filtered);
    }

• [ ] Visitor pattern for matching criteria - take a look at the way they use the visitor pattern to match collection elements against a given set of criteria. It's pretty clever. I want something like this.

I found another interesting Collections library which is actually implemented as a Symfony bundle, here: http://jmsyst.com/libs/PHP-Collection

• [ ] SequenceCollection and/or IsSequential trait

I've only given it a rudimentary glance, but one thing I liked and will most likely want to implement in my collections classes is a "SequentialCollection" or possibly a "IsSequential" trait. This would add functionality for collections where their order ALWAYS MATTERS. They are a sequence of elements. This would be useful for things such as job queues where the order they are executed matters (FIFO). Or maybe like a collection of orders where the earliest orders receive the highest priority. I'm sure there are tons of other applications for a sequential collection but I can't think properly right now.

[nozavroni]

collections have been abstracted to their own library/repo - nozavroni/collect