How Monoids are useful in Programming?

[badwolf]

I THINK FORBIDDING LOWERCASE CHARACTERS WOULD BE A GREAT RESTRICTION.

[red_reaper]

Now that's a epic haskell programming video

[valigotech]

I have shown this video to my React codebase. It turned into Elm

[joriskbos]

Whenever he says "what do I need for that?" The answer is always a function

[gillchristiang]

"that looks like something and average javascript programmer would write and is extremely lame"


lmfao this is why I watch your videos (oh and yeah I work with JS for a living)

[LeoOno]

following the logical sequence of your thought to arrive at the final composite function of all predicates using monoids was amazing, very enlightening so thanks a lot :)
!

[BryceTheGrand]

You could just create a function "f = (or .) . sequence"
This is a function that when given a list of functions of type [Char -> Bool] it returns a single function of type Char -> Bool.
This uses Monads by pulling "Char ->" outside of the list and returning a list of [Bool], which then uses "or" to see if one is true.
Or, to get it all in one line:
isForbidden = or . sequence [isBraille, isDigit, isUpper]

[MrRedstonefreedom]

If I ever pickup haskell, I saved this video since it's the fastest whirlwind tour of almost every aspect of the language environment 😂 -- in under 10 minutes!

help system, errors, composition, libraries, it's got it all

[fakt]

I knew about such a powerful tool as monoids before but I didn't know that any function that returns a monoid is also a monoid and it can be used in a very predictable way. Thank you.

[WilcoVerhoef]

*isForbidden c = any ($c) [ isEmoji, isBraille ]*

I don't like importing lesser known functions when the alternative is just as concise.

[nevokrien]

This is so bizarre he changed his tune so much

[СергейКузнецов-вюш]

More Haskell videos, they are so epic!

[japrogramer]

I used to Haskell but than I took a python to the knee.

[smuecke]

Why the hassle with importing stuff?

isForbidden c = any $ map ($ c) [isBraille, isEmoji]

[robertodantas]

I've been learning a lot from you! Your videos are great! Congrats! 👏👏👏

[jamma]

These are the best Haskell tutorials I've seen!

[Tomyb]

Apart from the other nice solutions or variations that have been outlined here in the comments, I wanted to mention that there is no need to fmap a newtype data constructor just to satisfy the type checker, given that newtypes are a no-op at runtime. All newtype instances are coercible with their underlying type, so you should be able to use the ```coerce``` function from Data.Coercible to turn them into Any or All with no runtime cost.

You probably need some type signature to clarify which instance to coerce into. Something like ```(coerce :: [a -> Bool] -> [a -> Any])``` or better yet
```isForbidden = getAny . (fold $ coerce predicates :: Char -> Any) where ...```

[AndrewBrownK]

I think the "m" in "mempty", "mappend", and "mconcat" stands for "M"onoid

[aBamieh]

Cool, i get so excited when you post haskell content

[danielsmith]

i like how there's an efficient solution 1:25 into the video but it's scrapped for epic haskell hubris