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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. Re: Antiderivative (indefinite integral)? (Twan van Laarhoven) 2. cabal install error: (Illegal instance declaration for `StrictByteString String') (miro) 3. can't install hackage package (Emmanuel Touzery) 4. Re: can't install hackage package (Emmanuel Touzery) 5. Re: can't install hackage package (Hartmut) 6. Fwd: Re: can't install hackage package (Emmanuel Touzery) ---------------------------------------------------------------------- Message: 1 Date: Mon, 21 Jan 2013 16:30:26 +0100 From: Twan van Laarhoven <twa...@gmail.com> Subject: Re: [Haskell-beginners] Antiderivative (indefinite integral)? To: beginners@haskell.org Message-ID: <50fd5f12.6060...@gmail.com> Content-Type: text/plain; charset=UTF-8; format=flowed If you don't care about efficiency, you can define antideriv :: (Int -> Int) -> Int -> Int antideriv f x | x >= 0 = sum [ f y | y <- [0..x-1] ] | x < 0 = - sum [ f y | y <- [x..-1] ] which has the property that antideriv f x1 - antideriv f x0 == sum [f x | x <- [x0..x1-1]] Twan On 19/01/13 19:55, Martin Drautzburg wrote: > Hello all, > > not strictly a Haskell question, but anyways ... > > is it possible to compute the antiderivative of a function f::Int->Int ? > > I understand that you can compute the definite integral by simply summing up > the values of f within a given interval. > > My first guess would be: no this is not possible. The antiderivative F of a > function f::Int->Int needs to have the property that F(b) - F(a) must be the > sum of f within [a,b]. To do this I must know all values withib [a,b]. But at > the time I compute the antiderivative I do not know this interval yet. > > What is striking me is that in calculus I can often symbolically compute the > antiderivative and I get a simple function, and I can get the value of F for a > given x and I get a simple number. Why is that so? > ------------------------------ Message: 2 Date: Mon, 21 Jan 2013 20:43:17 +0100 From: miro <miroslav.kar...@gmail.com> Subject: [Haskell-beginners] cabal install error: (Illegal instance declaration for `StrictByteString String') To: beginners@haskell.org Message-ID: <50fd9a55.8030...@gmail.com> Content-Type: text/plain; charset="iso-8859-1"; Format="flowed" Hi, please,....I'm trying to install one package (neo4j-haskell-http-client) and below is the error I'm getting. Pls. any ideas how can I fix that? --------------- 1 of 1] Compiling Data.ByteString.Class ( Data/ByteString/Class.hs, dist/build/Data/ByteString/Class.o ) Data/ByteString/Class.hs:39:10: Illegal instance declaration for `StrictByteString String' (All instance types must be of the form (T a1 ... an) where a1 ... an are *distinct type variables*, and each type variable appears at most once in the instance head. Use -XFlexibleInstances if you want to disable this.) In the instance declaration for `StrictByteString String' Data/ByteString/Class.hs:55:10: Illegal instance declaration for `LazyByteString String' (All instance types must be of the form (T a1 ... an) where a1 ... an are *distinct type variables*, and each type variable appears at most once in the instance head. Use -XFlexibleInstances if you want to disable this.) In the instance declaration for `LazyByteString String' Updating documentation index /Users/miro/Library/Haskell/doc/index.html cabal: Error: some packages failed to install: bytestring-class-0.0.0 failed during the building phase. The exception was: ExitFailure 1 neo4j-haskell-0.4.1 depends on bytestring-class-0.0.0 which failed to install. --------------- cheers, m. -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://www.haskell.org/pipermail/beginners/attachments/20130121/a2ec26ae/attachment-0001.htm> ------------------------------ Message: 3 Date: Mon, 21 Jan 2013 20:53:29 +0100 From: Emmanuel Touzery <etouz...@gmail.com> Subject: [Haskell-beginners] can't install hackage package To: "beginners@haskell.org" <beginners@haskell.org> Message-ID: <cac42remcxhbnmpesyfqqh4sfo03qtak49bab90k7exk8msm...@mail.gmail.com> Content-Type: text/plain; charset="iso-8859-1" Hello, I've been using this hackage package "rex" without problems on two computers (linux, windows) but now I fail setting it up on a third computer which confuses me, and the error message is not really enlightening for me: $ cabal update Downloading the latest package list from hackage.haskell.org $ cabal --version cabal-install version 1.16.0.2 using version 1.16.0.3 of the Cabal library $ cabal install rex Resolving dependencies... cabal: Could not resolve dependencies: trying: rex-0.3.1 Any idea? Thank you! Emmanuel -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://www.haskell.org/pipermail/beginners/attachments/20130121/73d457d6/attachment-0001.htm> ------------------------------ Message: 4 Date: Mon, 21 Jan 2013 21:10:10 +0100 From: Emmanuel Touzery <etouz...@gmail.com> Subject: Re: [Haskell-beginners] can't install hackage package To: "beginners@haskell.org" <beginners@haskell.org> Message-ID: <cac42renhveeyo1g7ppx5a66tgn7rqteoycdf0swxjvdycjv...@mail.gmail.com> Content-Type: text/plain; charset="iso-8859-1" This is on fedora18 if it can help. On 21 Jan 2013 20:53, "Emmanuel Touzery" <etouz...@gmail.com> wrote: > Hello, > > I've been using this hackage package "rex" without problems on two > computers (linux, windows) but now I fail setting it up on a third computer > which confuses me, and the error message is not really enlightening for me: > > $ cabal update > Downloading the latest package list from hackage.haskell.org > $ cabal --version > cabal-install version 1.16.0.2 > using version 1.16.0.3 of the Cabal library > $ cabal install rex > Resolving dependencies... > cabal: Could not resolve dependencies: > trying: rex-0.3.1 > > Any idea? > > Thank you! > > Emmanuel > -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://www.haskell.org/pipermail/beginners/attachments/20130121/119c615c/attachment-0001.htm> ------------------------------ Message: 5 Date: Mon, 21 Jan 2013 21:36:12 +0100 From: Hartmut <hartmut0...@googlemail.com> Subject: Re: [Haskell-beginners] can't install hackage package To: beginners@haskell.org Message-ID: <50fda6bc.8000...@googlemail.com> Content-Type: text/plain; charset="iso-8859-1"; Format="flowed" Hi, I wanted to try this under Windows also, but there are even more problems, since "pcre-light" dependency is not available (perhaps in case of using MSys, MingW) Hartmut Windows, cabal 1.16.0.2, I got cabal install rex --dry-run Resolving dependencies... In order, the following would be installed (use -v for more details): hslogger-1.2.1 MissingH-1.2.0.0 pcre-light-0.4 split-0.2.1.1 th-lift-0.5.5 th-orphans-0.6 haskell-src-meta-0.6.0.1 rex-0.3.1 cabal install Resolving dependencies... Configuring pcre-light-0.4... cabal: Missing dependency on a foreign library: * *Missing C library: pcre* This problem can usually be solved by installing the system package that provides this library (you may need the "-dev" version). If the library is already installed but in a non-standard location then you can use the flags --extra-include-dirs= and --extra-lib-dirs= to specify where it is. cabal: Error: some packages failed to install: pcre-light-0.4 failed during the configure step. The exception was: ExitFailure 1 rex-0.3.1 depends on pcre-light-0.4 which failed to install. Am 21.01.2013 21:10, schrieb Emmanuel Touzery: > > This is on fedora18 if it can help. > > On 21 Jan 2013 20:53, "Emmanuel Touzery" <etouz...@gmail.com > <mailto:etouz...@gmail.com>> wrote: > > Hello, > > I've been using this hackage package "rex" without problems on > two computers (linux, windows) but now I fail setting it up on a > third computer which confuses me, and the error message is not > really enlightening for me: > > $ cabal update > Downloading the latest package list from hackage.haskell.org > <http://hackage.haskell.org> > $ cabal --version > cabal-install version 1.16.0.2 > using version 1.16.0.3 of the Cabal library > $ cabal install rex > Resolving dependencies... > cabal: Could not resolve dependencies: > trying: rex-0.3.1 > > Any idea? > > Thank you! > > Emmanuel > > > > _______________________________________________ > Beginners mailing list > Beginners@haskell.org > http://www.haskell.org/mailman/listinfo/beginners -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://www.haskell.org/pipermail/beginners/attachments/20130121/9af3983a/attachment-0001.htm> ------------------------------ Message: 6 Date: Mon, 21 Jan 2013 21:40:55 +0100 From: Emmanuel Touzery <etouz...@gmail.com> Subject: [Haskell-beginners] Fwd: Re: can't install hackage package To: "beginners@haskell.org" <beginners@haskell.org> Message-ID: <cac42rekxoosnqosx-kkqaf3+yzg+y7cnt0g2ictr-wwmyp5...@mail.gmail.com> Content-Type: text/plain; charset="iso-8859-1" I made it work on another windows computer by copying a pcre.dll i found on internet and setting some environment variables. It's not difficult but right now i forgot the details.. ---------- Forwarded message ---------- From: "Hartmut" <hartmut0...@googlemail.com> Date: 21 Jan 2013 21:37 Subject: Re: [Haskell-beginners] can't install hackage package To: <beginners@haskell.org> Hi, I wanted to try this under Windows also, but there are even more problems, since "pcre-light" dependency is not available (perhaps in case of using MSys, MingW) Hartmut Windows, cabal 1.16.0.2, I got cabal install rex --dry-run Resolving dependencies... In order, the following would be installed (use -v for more details): hslogger-1.2.1 MissingH-1.2.0.0 pcre-light-0.4 split-0.2.1.1 th-lift-0.5.5 th-orphans-0.6 haskell-src-meta-0.6.0.1 rex-0.3.1 cabal install Resolving dependencies... Configuring pcre-light-0.4... cabal: Missing dependency on a foreign library: * *Missing C library: pcre* This problem can usually be solved by installing the system package that provides this library (you may need the "-dev" version). If the library is already installed but in a non-standard location then you can use the flags --extra-include-dirs= and --extra-lib-dirs= to specify where it is. cabal: Error: some packages failed to install: pcre-light-0.4 failed during the configure step. The exception was: ExitFailure 1 rex-0.3.1 depends on pcre-light-0.4 which failed to install. Am 21.01.2013 21:10, schrieb Emmanuel Touzery: This is on fedora18 if it can help. On 21 Jan 2013 20:53, "Emmanuel Touzery" <etouz...@gmail.com> wrote: > Hello, > > I've been using this hackage package "rex" without problems on two > computers (linux, windows) but now I fail setting it up on a third computer > which confuses me, and the error message is not really enlightening for me: > > $ cabal update > Downloading the latest package list from hackage.haskell.org > $ cabal --version > cabal-install version 1.16.0.2 > using version 1.16.0.3 of the Cabal library > $ cabal install rex > Resolving dependencies... > cabal: Could not resolve dependencies: > trying: rex-0.3.1 > > Any idea? > > Thank you! > > Emmanuel > _______________________________________________ Beginners mailing listBeginners@haskell.orghttp://www.haskell.org/mailman/listinfo/beginners _______________________________________________ Beginners mailing list Beginners@haskell.org http://www.haskell.org/mailman/listinfo/beginners -------------- next part -------------- An HTML attachment was scrubbed... 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