That’s an impressive step in complexity! FWIW, for ‘f x y = x <> " " <> y’ that website gave the same result as the book… ‘f = (<>) . (<> " ")’… so it seems to do a good job of giving a simplified solution. Understood re only using point-free for simple, clear cases… though it was a good exercise for me to understand what’s going on with the function composition operator (.). Thank you! Brad Sent from my iPhone

On Sep 12, 2023, at 1:08 AM, Sylvain Henry wrote:

Hi,

https://pointfree.io/ gives:

Input: f x y z = x <> " " <> y <> " " <> z

Output: f = ((<>) .) . flip flip " " . ((<>) .) . (<>) . (<> " ")

So no, it's not something simple!

For clarity I would recommend using the non-point-free version, even in the case given in the book. Use point-free only in simple cases like `map (+ 1)` where the meaning is obvious.

Sylvain

...

On 12/09/2023 02:45, Brad Smith wrote: I just started working my way through a Haskell book... first time with functional programming. Mid way through the first chapter she's introducing point-free programming with a trivial example transitioning from not point-free...

makeGreeting salutation person = salutation <> " " <> person

to point free...

makeGreeting' = (<>) . (<> " ")

After a little playing with it... it seems to make sense. So I thought I'd try evolving from salutation and name to salutation, first, and last names. But, after a bit of tinkering, I haven't been able to make it work...

I'm sure it's something simple (one way or the other)... any help would be appreciated!

Brad

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