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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. Bounded number types? (stuebinm) 2. Creating a Triple List from a List (A. Mc.) 3. Re: Creating a Triple List from a List (Francesco Ariis) ---------------------------------------------------------------------- Message: 1 Date: Sat, 27 Feb 2021 19:00:27 +0100 From: stuebinm <stueb...@disroot.org> To: The Haskell-Beginners Mailing List - Discussion of primarily beginner-level topics related to Haskell <beginners@haskell.org> Subject: [Haskell-beginners] Bounded number types? Message-ID: <004ce73c-486d-be27-bccc-68a7f00aa...@disroot.org> Content-Type: text/plain; charset="utf-8"; Format="flowed" Hi all, I'm wondering: is there any type that represents e.g. a floating point value that is guaranteed to be within some interval (e.g. [0,1]?). My practical use-case would be that I'm reading in input data from json, which may be ill-behaved — obviously I could just manually check, and then keep track of which numbers in which record fields are within which intervals, but coming from less strongly typed programming languages I wonder if there would be a "typed" way to do this, too. -------------- next part -------------- A non-text attachment was scrubbed... Name: OpenPGP_0x695C841098BECF1D.asc Type: application/pgp-keys Size: 3131 bytes Desc: not available URL: <http://mail.haskell.org/pipermail/beginners/attachments/20210227/d108a61f/attachment-0001.key> -------------- next part -------------- A non-text attachment was scrubbed... Name: OpenPGP_signature Type: application/pgp-signature Size: 840 bytes Desc: OpenPGP digital signature URL: <http://mail.haskell.org/pipermail/beginners/attachments/20210227/d108a61f/attachment-0001.sig> ------------------------------ Message: 2 Date: Sat, 27 Feb 2021 18:07:21 -0800 From: "A. Mc." <47dragonf...@gmail.com> To: beginners@haskell.org Subject: [Haskell-beginners] Creating a Triple List from a List Message-ID: <CAOsti3=ittf0pl4txtwljvvkfj2trwd-kaxdf9hmjc78qze...@mail.gmail.com> Content-Type: text/plain; charset="utf-8" Hello, What is the best way to take: [1, 2, 3, 4 ] And convert it to: [ [ [ 1 ], [ 2 ] ], [ [3]. [4] ] ] so that each member pair is: [ [1], [2] ] roughly analogous to a 1x2 vector? Thanks in advance and thank you for your time. -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://mail.haskell.org/pipermail/beginners/attachments/20210227/3a966693/attachment-0001.html> ------------------------------ Message: 3 Date: Sun, 28 Feb 2021 03:29:27 +0100 From: Francesco Ariis <fa...@ariis.it> To: The Haskell-Beginners Mailing List - Discussion of primarily beginner-level topics related to Haskell <beginners@haskell.org> Subject: Re: [Haskell-beginners] Creating a Triple List from a List Message-ID: <20210228022927.GA30216@extensa> Content-Type: text/plain; charset=utf-8 Il 27 febbraio 2021 alle 18:07 A. Mc. ha scritto: > Hello, > > What is the best way to take: > [1, 2, 3, 4 ] > > And convert it to: > > [ [ [ 1 ], [ 2 ] ], [ [3]. [4] ] ] > > so that each member pair is: > > [ [1], [2] ] > > roughly analogous to a 1x2 vector? A 1×2 vector would be > [[1 2], [3, 4]] am I wrong? If so, a quick and dirty solution could be d2 :: [a] -> [[a]] d2 [] = [] d2 [a] = error "odd element" d2 as = let (is, es) = splitAt 2 as in is : d2 es -- λ> d2 [1..6] -- [[1,2],[3,4],[5,6]] ------------------------------ Subject: Digest Footer _______________________________________________ Beginners mailing list Beginners@haskell.org http://mail.haskell.org/cgi-bin/mailman/listinfo/beginners ------------------------------ End of Beginners Digest, Vol 151, Issue 14 ******************************************