True but some still wants me to understand what a monofunctor is or something that sounds like a disease to do things like print to screen or get a random number

I feel that is the biggest barrier to their adoption nowadays (and also silly things like requiring ;; at the end of the line)

Pure functions are a good theoretical exercise but they can't exist in practice.

▲ jacquesm 4 hours ago | parent | next [-]

> Pure functions are a good theoretical exercise but they can't exist in practice.

Well, they can. But not all the way up to the top level of your program. But the longer you can hold off from your functions having side effects the more predictable and stable your codebase will be, with as an added benefit fewer bugs and less chance of runtime issues.

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DonHopkins 3 hours ago | parent | next [-]

Yes, but they're "Hello world!" hostile, so traditional programming language pedagogy doesn't work well.

Q: How many Prolog programmers does it take to change a lightbulb?

A: Yes.

	▲	mchaver 2 hours ago \| parent [-]
		I imagine LLMs have already thrown traditional programming language pedagogy out the window.

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raverbashing 2 hours ago | parent | prev [-]

Yes I agree, pure functions are good building blocks (for the most part), but I don't think the current abstractions and ways of bridging the FP and Procedural world are good enough

Also have you managed to eliminate the side effect of your IP register changing when your program is running? ;)

▲ roryc89 4 hours ago | parent | prev [-]

In most FP languages it is simple to print to screen and get a random number.

Pure functions often exist in practice and are useful for preventing many bugs. Sure, they may not be suitable for some situations but they can prevent a lot of foot guns.

Here's a Haskell example with all of the above:

  import System.Random (randomRIO)

  main :: IO ()
  main = do
    num <- randomRIO (1, 100)
    print $ pureFunction num

  pureFunction :: Int -> Int
  pureFunction x = x * x + 2 * x + 1