AOSA4 - 500 lines or less

This is my review and summary of the latest AOSA book "500 Lines or Less", where experienced programmers solve interesting problems in short(-ish) programs. The book is available for free online, but if you are interested and can afford it, please consider buying the PDF or paperback versions.

Blockcode: A visual programming toolkit

Dethe Elza introduces us to a minimal version of Waterbear. Waterbear wraps existing language with a block-based syntax. (Block-based languages are visual programming languages like Scratch and Lego Mindstorms.)

Since Waterbear is browser-based, we are shown well-structured, understandable JavaScript code, as far as I can tell - I don't use JavaScript normally, and I enjoyed reading the code shown here, especially since it does not rely on external libraries such as jQuery, and includes comments and necessary clean-up routines.

In addition to the Code introduced, I want to highlight the excellent "Lessons Learned" section in the end of the chapter. First, we get a very concise take on the MVC pattern in modern browser application. Dethe then reflects on the advantages of being forced to reduce a larger project to 500 LOC or less:

• a small prototype helps you realize what core features of your project are, and what features are not important or even historical and should be removed
• a small prototype helps you experience at very small costs/penalties for failure
• a small prototype makes it more apparent what features should be introduced next