As a follow up to a previous post where he discussed reverse polish notation, Nick Halstead has decided to split off the code he created for that previous post into a new, sleeker post without much of the explanation and heavy on the code.

My last post about back to basics covered reverse polish notation including a link to a RPN parser which I wrote to allow people to learn by example (best way in my opinion and in yours). The post got quite long and the PHP code was not really relevant to the subject so I have decided to include in this separate post instead.

There's two parts to the post - a pseudo-code explanation that an overview of how things work and the actual code, a block of code (in the 30 line area) that runs through each item and, based on a token, pushes the value into the array differently.