This chapter focused on an attention to cleanliness. When coding we’re often so focused on solving the problem at hand that it’s all too tempting to tick it off as done without properly considering errors. Revisiting your code, testing it thoroughly and tidying it up are all important parts of the coding process.

While cleaning up our code, we also learned some new special forms, explored the meaning of type errors and wrote some more interesting functions.

If you’re keen, take out a pen and paper and map out what you’ve learned: