[Haskell-beginners] MaximumBy

[Alexander Chen]

Hi,

maximumBy :: Foldable t => (a -> a -> Ordering) -> t a -> a

its in the Data.List

May 22, 2020 8:33:33 PM CEST "Daniel van de Ghinste (Lord_Luvat)" <danielvandeghinste at gmail.com> wrote:Hi,

Maybe I’m on a different version, but I don’t see a function called maximumBy in my base Prelude. Can you give us a type signature for the function? If you’re not sure how to do that just type:
Prelude> :t maximumBy
In your ghci interpreter and it should return the type signature of whatever you have after ‘:t ‘ (this works for compound expressions too if you put them in brackets)

Perhaps maximumBy is what you’re meant to call your rewrite of the existing function I see called ‘maximum’ (seems to do the same thing). Let me know if thats the case and I can explain how it works.

Best regards,
Daniel van de Ghinste

On 22 May 2020, at 20:20, Alexander Chen <alexander at chenjia.nl> wrote:

Hi,

I want to re-write a function maximumBy (its an assignment).

However, I don't get how it works.

>maximumBy compare [1,53,9001, 10]
9001

but what does it actually do to get there? 

thanks in advance.

best,

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