\n<\/p>\n
The content of this tutorial is intended to apply to PoC5. Most of the instructions given below will not work in the older PoC4 implementations of AlethZero (C++) and Ethereal (Go)<\/i><\/p>\n
Over the last few weeks, we have made a large number of changes to the Ethereum protocol. POC4, introducing a large body of changes made by Gavin Wood and myself, was announced as an informal description<\/a> two weeks ago, and has been formally specified in Gavin Wood\u2019s \u201cyellow paper\u201d at http:\/\/gavwood.com\/Paper.pdf<\/a>. The protocol spec did change substantially, but at the same time things are solidifying; we know why we want transactions to pay fees instead of contracts, so that\u2019s not likely to change, we know that code and data will be separate, and the byte-based code and memory and 32-byte-block-based stack and storage are unlikely to change, and we know that the workings of the EVM in general will be similar to what they are now instead of some kind of elaborate Merkle-code-tree construction. POC4 has given myself what I wanted out of Ethereum Script 2<\/a>, Gavin a much more optimization-friendly VM architecture, and users a shiny new currency<\/a>. Meanwhile, Chen Houwu, Heiko Kees and Konrad Feldmeier have taken the lead as our main Python developers, and the networking side of the pyethereum client is getting to the point where it is getting ready to talk to Go and C++. At the same time, aside from all of the managerial tasks that are part and parcel of having a key role in a large project, I have taken it upon myself to bring up to speed the pyethereum VM implementation and the compiler for the HLL programming language.<\/p>\n The purpose of this post will be to provide an in-depth technical tutorial into the workings of pyethereum and Serpent, and show you how you can start writing the tools to build your own contracts and applications. The Bitcoin Expo hackathon is happening today and tomorrow, so feel free to make an Ethereum contract your project if you are among those attending.<\/p>\n First of all, importantly, HLL is no longer called HLL; the language is now called Serpent. Why? Because it\u2019s basically Python.<\/p>\n With recent upgrades to the compiler, Serpent is now a highly feature-filled programming language, with powerful features including:<\/p>\n The intent of the Serpent language is to make programming smart contracts and decetralized applications in Ethereum as easy as programming boring command line apps is in Python. The language is designed to be maximally clean and maximally simple, combining the benefits of a compiled language with an easy-to-use coding experience. Just the logic, and nothing but the logic. Unfortunately, floating point numbers are missing, as are higher-order constructs like list comprehensions and closures, but aside from that Serpent has basically everything that you need.<\/p>\n\n