I was looking for F# book Bedok National Library, but couldn’t find it. So I borrowed this book instead.

After finishing it, I can’t say I like it. Maybe because the book is aimed towards Java programmers (the functional part is done in Groovy/Scala). But at least I was not totally wasted my time. I picked up few things, mostly on the concept of functional programming. Here’s what I learned from this book.

Why Functional Programming?

Should we learn Functional Programming (FP)? Apparently yes. Here’s why:

1. We can closely model the solution exactly like how we would solve it in our brain
2. FP allows us to closely mirrors the mathematical function which in turn allows us to design stronger algorithm

Feature of Functional Programming

1. First class function: function which takes function as parameter, or returns a function.
2. Pure function: function that has no side effects
3. Recursion: function which calls itself
4. Immutable variables: variables which once set, the value can’t be changed
5. Non-strict (lazy-loading) evaluation: only produce the result when the the result is consummated
6. Pattern matching: match the variable’s value to a pattern.
7. Anonymous function: function which don’t need to give name. E.g. Lambda function.
8. Closures: a type of anonymous function which is used as a function factory. Using closure, we can easily build functions then pass them to other functions while referring to local variables

The book was quite thin for a programming book standard 😀 I found the book quite easy to follow. Maybe because I have accidentally familiar with functional concepts used in jQuery.