Parsedown has also been moving towards compliance with CommonMark.<p><a href="http://parsedown.org/" rel="nofollow">http://parsedown.org/</a>
<a href="https://github.com/thephpleague/commonmark/blob/master/src/Util/ArrayCollection.php#L112" rel="nofollow">https://github.com/thephpleague/commonmark/blob/master/src/U...</a> What is the Point of abstracting away "empty?"
Aha! The controversial "Standard Markdown" (is that what it used to be called?) has been renamed to "CommonMark", hopefully avoiding the controversy. (Controversial because Gruber didn't like them using the Markdown name in a standardization effort).<p>I'm glad. I hope to see implementations continue to spread.
Sorry to add a critic. If you want to make your PHP classes easy to extend, refrain from private and prefer protected. Otherwise, a developer that wants to extend one of your classes will need to also override (i.e. copy and paste) into her class all private members called from the members she really wants to override.