On 5/26/11 6:27 PM, Costello, Roger L. wrote:

Hi Folks,

I am working on a project and am trying hard to write the code in a functional style.

Sadly, upon reviewing what I’ve written, I realize that I am not succeeding. I just devised a recipe for solving the problem and then created functions corresponding to steps in the recipe. I am still thinking imperatively, not functionally.

Is there a book or article that describes how to approach problems from a functional mindset?

How did you “flip the switch” in your brain to the functional mindset?

Hi Roger,

reminding oneself to take it literal, I found can be quite clarifying.

At the core of it, I found it helps to "avoid thinking state", i.e. putting stuff into variables. If you find yourself doing that a lot, it's a sign for the wrong track. You'll find, again and again, you don't need to keep that state. Just pass up the result of a call.

Inversely, avoid "lines that do not deliver a result", which "just do something". Or, to be precise, note when you don't use a result.

Taking "functional programming" literal, you'd try thinking about the entire problem as but nested function calls with no intermediary state holders, rather than "implicitly tacting state tables", if that makes any sense.

Best,
Henning

/Roger


_______________________________________________
Beginners mailing list
Beginners@haskell.org
http://www.haskell.org/mailman/listinfo/beginners