Skimmers Guide for Week 9 of Functional Programming for the Object-Oriented Programmer

“…don’t read Lisp functions from top to bottom… look for the most important code (typically closer to the bottom of the function, often the most visually dense) and read it first.“

What did we read about?

This was our ninth week of ‘Functional Programming for the Object-Oriented Programmer‘ by Brian Manick.

We began on Page 90, at the start of section “7.6 Processing Sequences of Maps”. We did the two exercises, starting on Page 94, and then continued reading through to Page 98 at the end of chapter 7.

Continuing with the student courses example, we work through how to manipulate the course data. New and powerful features of Clojure are introduced, such as destructing and external binding.

Rather interesting we finally touch upon design at a high level within functional programming. Brian discusses his thoughts on how to handle encapsulation within a dynamic language as well.

What stood out?

• Destructuring arguments, Page 92, is an incredibly useful tool that reminds me a lot of pattern matching. Brian covers it very well succinctly, although there promises to be an entire chapter on it later!
• Avoiding argument passing by using external binding is a very interesting topic (starting on the bottom of  Page 94). Again it will be covered in a later chapter but is raises the interesting design question on where and when to “nest functions”?

If you read nothing else this week…

• Information Hiding, Page 98, brief but thought provoking section on encapsulation. Do you think using private helper functions and file based modularity is enough?
• Discussion of the pros and cons of nesting functions, bottom of Page 96. In functional programming, does deciding on the number of higher level functions to use and their responsibilities reflect the design of classes in imperative programming?