/prague/ Q&A

Ask /prog/ anything.

Although don't expect an answer or even a good one.

Also, keep it /prog/ related.

>>42

I'm familiar with object-oriented programming, but what is functional programming?

Object-oriented programming is when things are centered around objects and their composition (inheritance, for example), and functions/procedures/methods are defined in terms of/around objects. Functional programming is when emphasis is put on functions instead and their composition, and objects/structures are just things that functions operate on. Purely functional programming is the extremest form of this, where all code is part of functions (in the mathematical sense) and so there is no mutation ("assignment"). Turns out that all of the above are equal in computational power (i.e. there are no computations that one of them can do but the other ones can't), so this is really just about clarity and efficiency and all those other things.

Are they compatible? Are they reconcilable?

Yes; an excellent example is Common Lisp and the CLOS.

Do individual programmers generally favor one over the other, or do they utilise each when appropriate?

The average programmer has the IQ of a highly-trained rhesus monkey. That being said, a Haskell programmer will almost always use functional programming (even when clarity/performance are hurt) while a Java programmer will almost use object-oriented programming (because they don't know any better).

Are the any other styles or philosophies of note or of relevance?

Read up about defmacro. Also read SICP (or if you find it too hard, something like Land of Lisp).