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You can reach the person managing the list at beginners-ow...@haskell.org When replying, please edit your Subject line so it is more specific than "Re: Contents of Beginners digest..." Today's Topics: 1. MaximumBy (Alexander Chen) 2. Re: MaximumBy (Daniel van de Ghinste (Lord_Luvat)) 3. Re: MaximumBy (Alexander Chen) 4. Re: Understanding types and constructors more thoroughly (Magnus Therning) 5. Re: MaximumBy (Francesco Ariis) 6. Re: MaximumBy (Ut Primum) ---------------------------------------------------------------------- Message: 1 Date: Fri, 22 May 2020 20:20:38 +0200 (CEST) From: Alexander Chen <alexan...@chenjia.nl> To: beginners@haskell.org Subject: [Haskell-beginners] MaximumBy Message-ID: <746561064.19225.1590171638...@ichabod.co-bxl> Content-Type: text/plain; charset="utf-8" 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, -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://mail.haskell.org/pipermail/beginners/attachments/20200522/7b1cdb0d/attachment-0001.html> ------------------------------ Message: 2 Date: Fri, 22 May 2020 20:33:33 +0200 From: "Daniel van de Ghinste (Lord_Luvat)" <danielvandeghin...@gmail.com> To: Alexander Chen <alexan...@chenjia.nl>, The Haskell-Beginners Mailing List - Discussion of primarily beginner-level topics related to Haskell <beginners@haskell.org> Subject: Re: [Haskell-beginners] MaximumBy Message-ID: <95b07d1e-14b7-46c1-9764-15d624f78...@gmail.com> Content-Type: text/plain; charset="utf-8" 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 <alexan...@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, > > > _______________________________________________ > Beginners mailing list > Beginners@haskell.org > http://mail.haskell.org/cgi-bin/mailman/listinfo/beginners -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://mail.haskell.org/pipermail/beginners/attachments/20200522/f31e65e2/attachment-0001.html> ------------------------------ Message: 3 Date: Fri, 22 May 2020 20:52:03 +0200 (CEST) From: Alexander Chen <alexan...@chenjia.nl> To: "Daniel van de Ghinste (Lord_Luvat)" <danielvandeghin...@gmail.com>, The Haskell-Beginners Mailing List - Discussion of primarily beginner-level topics related to Haskell <beginners@haskell.org> Subject: Re: [Haskell-beginners] MaximumBy Message-ID: <1715418034.21133.1590173523...@ichabod.co-bxl> Content-Type: text/plain; charset="utf-8" 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)" <danielvandeghin...@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 <alexan...@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, _______________________________________________ Beginners mailing list Beginners@haskell.org http://mail.haskell.org/cgi-bin/mailman/listinfo/beginners -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://mail.haskell.org/pipermail/beginners/attachments/20200522/3da57ad9/attachment-0001.html> ------------------------------ Message: 4 Date: Fri, 22 May 2020 21:02:09 +0200 From: Magnus Therning <mag...@therning.org> To: beginners@haskell.org Subject: Re: [Haskell-beginners] Understanding types and constructors more thoroughly Message-ID: <87h7w74wum....@therning.org> Content-Type: text/plain; charset="utf-8" Josh Diamond <evild...@live.co.uk> writes: > Actually I worked it out, no need for any help so please ignore Please consider writing how you solved it. Sometimes when searching the internet I come upon questions that the questioner then solve on her/his own, but _I_ don't get to see the solution. It robs me of an answer to my question, and the questioner is robbed of feedback and further insights. /M -- Magnus Therning OpenPGP: 0x927912051716CE39 email: mag...@therning.org twitter: magthe http://magnus.therning.org/ You can't depend on your judgement when your imagination is out of focus. — Mark Twain -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 832 bytes Desc: not available URL: <http://mail.haskell.org/pipermail/beginners/attachments/20200522/f0972d2d/attachment-0001.sig> ------------------------------ Message: 5 Date: Fri, 22 May 2020 21:10:43 +0200 From: Francesco Ariis <fa...@ariis.it> To: beginners@haskell.org Subject: Re: [Haskell-beginners] MaximumBy Message-ID: <20200522191043.GA14834@extensa> Content-Type: text/plain; charset=iso-8859-1 Hello Alexander, Il 22 maggio 2020 alle 20:20 Alexander Chen ha scritto: > 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? Do you know how to use foldr and friends? ------------------------------ Message: 6 Date: Fri, 22 May 2020 21:13:49 +0200 From: Ut Primum <utpri...@gmail.com> To: Alexander Chen <alexan...@chenjia.nl>, The Haskell-Beginners Mailing List - Discussion of primarily beginner-level topics related to Haskell <beginners@haskell.org> Subject: Re: [Haskell-beginners] MaximumBy Message-ID: <canjdmkjw6avdurgsq5x4eq-rciavtwdzrjnotxlcbfb3k1c...@mail.gmail.com> Content-Type: text/plain; charset="utf-8" Hi, if it is ok for you to work only with lists (not generic foldables), you could write it this way: maximumBy cmp [x] = x maximumBy cmp (x:y:xs) = if (cmp x y)==GT then maximumBy cmp (x:xs) else maximumBy cmp (y:xs) the signature is maximumBy :: (a -> a -> Ordering) -> [a] -> a Ut <http://www.avg.com/email-signature?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail> Mail priva di virus. www.avg.com <http://www.avg.com/email-signature?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail> <#m_-9203042563784922724_DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2> Il giorno ven 22 mag 2020 alle ore 20:53 Alexander Chen < alexan...@chenjia.nl> ha scritto: > 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)" < > danielvandeghin...@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 <alexan...@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, > > > _______________________________________________ > Beginners mailing list > Beginners@haskell.org > http://mail.haskell.org/cgi-bin/mailman/listinfo/beginners > > > > > > _______________________________________________ > Beginners mailing list > Beginners@haskell.org > http://mail.haskell.org/cgi-bin/mailman/listinfo/beginners > <http://www.avg.com/email-signature?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail> Mail priva di virus. www.avg.com <http://www.avg.com/email-signature?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail> <#DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2> -------------- next part -------------- An HTML attachment was scrubbed... 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