What task is best done in a functional programming style?

Question

I\'ve just recently discovered the functional programming style and I\'m convinced that it will reduce development efforts, make code easier to read, make software more main

Answer 1

Essentially, the functional paradigm is highly effective for parallel processing:

"The really interesting thing I want you to notice, here, is that as soon as you think of map and reduce as functions that everybody can use, and they use them, you only have to get one supergenius to write the hard code to run map and reduce on a global massively parallel array of computers, and all the old code that used to work fine when you just ran a loop still works only it's a zillion times faster which means it can be used to tackle huge problems in an instant.

Lemme repeat that. By abstracting away the very concept of looping, you can implement looping any way you want, including implementing it in a way that scales nicely with extra hardware."

http://www.joelonsoftware.com/items/2006/08/01.html