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Today's Topics:
1. Re: Problem installing EclipseFp in Eclipse (Norbert Melzer)
2. Re: Problem installing EclipseFp in Eclipse (Brent Yorgey)
3. replacing fold with scan! (raffa f)
4. Re: Problem installing EclipseFp in Eclipse (Robert Weisser)
----------------------------------------------------------------------
Message: 1
Date: Thu, 1 May 2014 01:19:36 +0200
From: Norbert Melzer <[email protected]>
To: The Haskell-Beginners Mailing List - Discussion of primarily
beginner-level topics related to Haskell <[email protected]>
Subject: Re: [Haskell-beginners] Problem installing EclipseFp in
Eclipse
Message-ID:
<ca+bcvsuh14yxve4pgx4ezcpfhjo6memvh2cbqgy3z6_za31...@mail.gmail.com>
Content-Type: text/plain; charset="utf-8"
Omit cabal-dev it is not maintained anymore and most of its functionality
is part of cabal already (cabal sandbox)
Am 01.05.2014 00:18 schrieb "Robert Weisser" <[email protected]>:
> I decided to try out Eclipse with the EclipseFP plug-in for Haskell.
> I downloaded Eclipse, and then started to install EclipseFP. At
> some point, I got a screen which said that I needed to install
> buildwrapper and scion-browser. It offered to install both
> of them, and optionally install hoogle, hlint, stylish-haskell,
> SourceGraph, and cabal-dev. The option to install the additional
> items was pre-checked. I left it checked. The installation of
> buildwrapper, etc. took a long time. It seemed to be going well
> until I saw the messages below, which say that installing SourceGraph
> will likely break several other packages, most of which were part
> of the EclipseFP installation.
>
> I am not a complete novice with Haskell but I am a complete novice
> with Cabal. I'm not sure what to do. Here are some options I have
> considered:
>
> 1. Use --force-reinstalls and hope for the best.
>
> 2. Try to resolve the problem with Cabal, although I don't know to
> do this.
>
> 3. Use EclipseFP without SourceGraph and cabal-dev.
>
> 4. Use EclipseFP without SourceGraph, but install cabal-dev using
> cabal on the command line.
>
> 5. Forget about Eclipse altogether, and go back to using vim.
>
> Any advice would be appreciated.
>
> By the way, I am using Haskell Platform 7.6.3.
>
> Here are the messages I saw in the Eclipse console window:
>
> <terminated> Installing executable SourceGraph
>
> Resolving dependencies...
> In order, the following would be installed:
> asn1-types-0.2.3 (new package)
> asn1-encoding-0.8.1.3 (new package)
> asn1-parse-0.8.1 (new package)
> bktrees-0.3.1 (new package)
> byteable-0.1.1 (new package)
> cereal-0.4.0.1 (new package)
> colour-2.3.3 (new package)
> cpphs-1.18.2 (new version)
> crypto-pubkey-types-0.4.2.2 (new package)
> cryptohash-0.11.4 (new package)
> digest-0.0.1.2 (new package)
> dlist-0.5 (new version)
> aeson-0.7.0.3 (reinstall) changes: dlist-0.7.0.1 -> 0.5
> data-default-instances-dlist-0.0.1 (reinstall) changes: dlist-0.7.0.1 ->
> 0.5
> data-default-0.5.3 (reinstall)
> cookie-0.4.1.1 (new package)
> haskell-src-exts-1.13.5 (new version)
> hslua-0.3.12 (new package)
> mime-types-0.1.0.4 (new package)
> multiset-0.2.2 (new package)
> pandoc-types-1.12.3.2 (new package)
> pem-0.2.2 (new package)
> polyparse-1.8 (new version)
> publicsuffixlist-0.1 (new package)
> http-client-0.3.2 (new package)
> regex-pcre-builtin-0.94.4.8.8.34 (new package)
> highlighting-kate-0.5.6.1 (new package)
> resourcet-0.4.10.2 (new version)
> securemem-0.1.3 (new package)
> crypto-cipher-types-0.0.9 (new package)
> cipher-aes-0.2.7 (new package)
> cipher-rc4-0.1.4 (new package)
> crypto-random-0.0.7 (new package)
> cprng-aes-0.5.2 (new package)
> crypto-numbers-0.2.3 (new package)
> crypto-pubkey-0.2.4 (new package)
> socks-0.5.4 (new package)
> temporary-1.1.2.5 (new package)
> text-stream-decode-0.1.0.5 (new package)
> conduit-1.0.17.1 (new version)
> http-client-conduit-0.2.0.1 (new package)
> wl-pprint-text-1.1.0.2 (new package)
> graphviz-2999.16.0.0 (new package)
> x509-1.4.11 (new package)
> x509-store-1.4.4 (new package)
> x509-system-1.4.5 (new package)
> x509-validation-1.5.0 (new package)
> tls-1.2.6 (new package)
> connection-0.2.1 (new package)
> http-client-tls-0.2.1.1 (new package)
> http-conduit-2.0.0.10 (new package)
> xml-1.3.13 (new package)
> texmath-0.6.6.1 (new package)
> yaml-0.8.8.2 (reinstall) changes: conduit-1.1.1 -> 1.0.17.1,
> resourcet-1.1.2
> -> 0.4.10.2
> zip-archive-0.2.2.1 (new package)
> pandoc-1.12.3.3 (new package)
> Graphalyze-0.14.0.2 (new package)
> SourceGraph-0.7.0.5 (new package)
> cabal: The following packages are likely to be broken by the reinstalls:
> stylish-haskell-0.5.10.0
> scion-browser-0.3.1
> persistent-template-1.3.1.3
> persistent-sqlite-1.3.0.5
> persistent-1.3.0.6
> buildwrapper-0.8.0
> dynamic-cabal-0.3.1
> Use --force-reinstalls if you want to install anyway.
>
>
> _______________________________________________
> Beginners mailing list
> [email protected]
> http://www.haskell.org/mailman/listinfo/beginners
>
>
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------------------------------
Message: 2
Date: Wed, 30 Apr 2014 20:40:07 -0400
From: Brent Yorgey <[email protected]>
To: [email protected]
Subject: Re: [Haskell-beginners] Problem installing EclipseFp in
Eclipse
Message-ID: <[email protected]>
Content-Type: text/plain; charset=us-ascii
There's no particular need for SourceGraph and definitely no need for
cabal-dev. I say try (3).
On Thu, May 01, 2014 at 12:18:05AM +0200, Robert Weisser wrote:
> I decided to try out Eclipse with the EclipseFP plug-in for Haskell.
> I downloaded Eclipse, and then started to install EclipseFP. At
> some point, I got a screen which said that I needed to install
> buildwrapper and scion-browser. It offered to install both
> of them, and optionally install hoogle, hlint, stylish-haskell,
> SourceGraph, and cabal-dev. The option to install the additional
> items was pre-checked. I left it checked. The installation of
> buildwrapper, etc. took a long time. It seemed to be going well
> until I saw the messages below, which say that installing SourceGraph
> will likely break several other packages, most of which were part
> of the EclipseFP installation.
>
> I am not a complete novice with Haskell but I am a complete novice
> with Cabal. I'm not sure what to do. Here are some options I have
> considered:
>
> 1. Use --force-reinstalls and hope for the best.
>
> 2. Try to resolve the problem with Cabal, although I don't know to
> do this.
>
> 3. Use EclipseFP without SourceGraph and cabal-dev.
>
> 4. Use EclipseFP without SourceGraph, but install cabal-dev using
> cabal on the command line.
>
> 5. Forget about Eclipse altogether, and go back to using vim.
>
> Any advice would be appreciated.
>
> By the way, I am using Haskell Platform 7.6.3.
>
> Here are the messages I saw in the Eclipse console window:
>
> <terminated> Installing executable SourceGraph
>
> Resolving dependencies...
> In order, the following would be installed:
> asn1-types-0.2.3 (new package)
> asn1-encoding-0.8.1.3 (new package)
> asn1-parse-0.8.1 (new package)
> bktrees-0.3.1 (new package)
> byteable-0.1.1 (new package)
> cereal-0.4.0.1 (new package)
> colour-2.3.3 (new package)
> cpphs-1.18.2 (new version)
> crypto-pubkey-types-0.4.2.2 (new package)
> cryptohash-0.11.4 (new package)
> digest-0.0.1.2 (new package)
> dlist-0.5 (new version)
> aeson-0.7.0.3 (reinstall) changes: dlist-0.7.0.1 -> 0.5
> data-default-instances-dlist-0.0.1 (reinstall) changes: dlist-0.7.0.1 -> 0.5
> data-default-0.5.3 (reinstall)
> cookie-0.4.1.1 (new package)
> haskell-src-exts-1.13.5 (new version)
> hslua-0.3.12 (new package)
> mime-types-0.1.0.4 (new package)
> multiset-0.2.2 (new package)
> pandoc-types-1.12.3.2 (new package)
> pem-0.2.2 (new package)
> polyparse-1.8 (new version)
> publicsuffixlist-0.1 (new package)
> http-client-0.3.2 (new package)
> regex-pcre-builtin-0.94.4.8.8.34 (new package)
> highlighting-kate-0.5.6.1 (new package)
> resourcet-0.4.10.2 (new version)
> securemem-0.1.3 (new package)
> crypto-cipher-types-0.0.9 (new package)
> cipher-aes-0.2.7 (new package)
> cipher-rc4-0.1.4 (new package)
> crypto-random-0.0.7 (new package)
> cprng-aes-0.5.2 (new package)
> crypto-numbers-0.2.3 (new package)
> crypto-pubkey-0.2.4 (new package)
> socks-0.5.4 (new package)
> temporary-1.1.2.5 (new package)
> text-stream-decode-0.1.0.5 (new package)
> conduit-1.0.17.1 (new version)
> http-client-conduit-0.2.0.1 (new package)
> wl-pprint-text-1.1.0.2 (new package)
> graphviz-2999.16.0.0 (new package)
> x509-1.4.11 (new package)
> x509-store-1.4.4 (new package)
> x509-system-1.4.5 (new package)
> x509-validation-1.5.0 (new package)
> tls-1.2.6 (new package)
> connection-0.2.1 (new package)
> http-client-tls-0.2.1.1 (new package)
> http-conduit-2.0.0.10 (new package)
> xml-1.3.13 (new package)
> texmath-0.6.6.1 (new package)
> yaml-0.8.8.2 (reinstall) changes: conduit-1.1.1 -> 1.0.17.1, resourcet-1.1.2
> -> 0.4.10.2
> zip-archive-0.2.2.1 (new package)
> pandoc-1.12.3.3 (new package)
> Graphalyze-0.14.0.2 (new package)
> SourceGraph-0.7.0.5 (new package)
> cabal: The following packages are likely to be broken by the reinstalls:
> stylish-haskell-0.5.10.0
> scion-browser-0.3.1
> persistent-template-1.3.1.3
> persistent-sqlite-1.3.0.5
> persistent-1.3.0.6
> buildwrapper-0.8.0
> dynamic-cabal-0.3.1
> Use --force-reinstalls if you want to install anyway.
> _______________________________________________
> Beginners mailing list
> [email protected]
> http://www.haskell.org/mailman/listinfo/beginners
------------------------------
Message: 3
Date: Wed, 30 Apr 2014 23:42:09 -0300
From: raffa f <[email protected]>
To: [email protected]
Subject: [Haskell-beginners] replacing fold with scan!
Message-ID:
<cahdwbej_6lmpdlawjewyt89hqhku8m+qr-rvj-ljg8bvddp...@mail.gmail.com>
Content-Type: text/plain; charset="utf-8"
hi everyone! here's my new problem. i wrote my version of filter:
filter' :: (a -> Bool) -> [a] -> [a]
filter' f = foldr (\x acc -> if f x then x:acc else acc) []
and it works! however, i wanted to use scan too. so i just replaced foldr
with scanr, to see what would happen:
filter'' :: (a -> Bool) -> [a] -> [a]
filter'' f = scanr (\x acc -> if f x then x:acc else acc) []
but that doesn't work! ghci gives me this:
folds.hs:15:59:
Couldn't match expected type `a' with actual type `[a0]'
`a' is a rigid type variable bound by
the type signature for filter'' :: (a -> Bool) -> [a] -> [a]
at folds.hs:14:13
In the second argument of `scanr', namely `[]'
In the expression:
scanr (\ x acc -> if f x then x : acc else acc) []
In an equation for filter'':
filter'' f = scanr (\ x acc -> if f x then x : acc else acc) []
Failed, modules loaded: none.
the problem seems to be with the start value of [], it seems? i don't
understand, i thought scan and fold worked pretty much the same. i learned
about these functions today, so i'm still trying to wrap my head around
them...
thank you!
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Message: 4
Date: Thu, 01 May 2014 05:17:57 +0200
From: "Robert Weisser" <[email protected]>
To: "The Haskell-Beginners Mailing List - Discussion of primarily
beginner-level topics related to Haskell" <[email protected]>
Subject: Re: [Haskell-beginners] Problem installing EclipseFp in
Eclipse
Message-ID: <[email protected]>
Content-Type: text/plain; charset="utf-8"
Thanks. That's great info.
----- Original Message -----
From: Norbert Melzer
Sent: 04/30/14 07:19 PM
To: The Haskell-Beginners Mailing List - Discussion of primarily beginner-level
topics related to Haskell
Subject: Re: [Haskell-beginners] Problem installing EclipseFp in Eclipse
Omit cabal-dev it is not maintained anymore and most of its functionality is
part of cabal already (cabal sandbox)
Am 01.05.2014 00:18 schrieb "Robert Weisser" < [email protected] >:
I decided to try out Eclipse with the EclipseFP plug-in for Haskell.
I downloaded Eclipse, and then started to install EclipseFP. At
some point, I got a screen which said that I needed to install
buildwrapper and scion-browser. It offered to install both
of them, and optionally install hoogle, hlint, stylish-haskell,
SourceGraph, and cabal-dev. The option to install the additional
items was pre-checked. I left it checked. The installation of
buildwrapper, etc. took a long time. It seemed to be going well
until I saw the messages below, which say that installing SourceGraph
will likely break several other packages, most of which were part
of the EclipseFP installation.
I am not a complete novice with Haskell but I am a complete novice
with Cabal. I'm not sure what to do. Here are some options I have
considered:
1. Use --force-reinstalls and hope for the best.
2. Try to resolve the problem with Cabal, although I don't know to
do this.
3. Use EclipseFP without SourceGraph and cabal-dev.
4. Use EclipseFP without SourceGraph, but install cabal-dev using
cabal on the command line.
5. Forget about Eclipse altogether, and go back to using vim.
Any advice would be appreciated.
By the way, I am using Haskell Platform 7.6.3.
Here are the messages I saw in the Eclipse console window:
<terminated> Installing executable SourceGraph
Resolving dependencies...
In order, the following would be installed:
asn1-types-0.2.3 (new package)
asn1-encoding-0.8.1.3 (new package)
asn1-parse-0.8.1 (new package)
bktrees-0.3.1 (new package)
byteable-0.1.1 (new package)
cereal-0.4.0.1 (new package)
colour-2.3.3 (new package)
cpphs-1.18.2 (new version)
crypto-pubkey-types-0.4.2.2 (new package)
cryptohash-0.11.4 (new package)
digest-0.0.1.2 (new package)
dlist-0.5 (new version)
aeson-0.7.0.3 (reinstall) changes: dlist-0.7.0.1 -> 0.5
data-default-instances-dlist-0.0.1 (reinstall) changes: dlist-0.7.0.1 -> 0.5
data-default-0.5.3 (reinstall)
cookie-0.4.1.1 (new package)
haskell-src-exts-1.13.5 (new version)
hslua-0.3.12 (new package)
mime-types-0.1.0.4 (new package)
multiset-0.2.2 (new package)
pandoc-types-1.12.3.2 (new package)
pem-0.2.2 (new package)
polyparse-1.8 (new version)
publicsuffixlist-0.1 (new package)
http-client-0.3.2 (new package)
regex-pcre-builtin-0.94.4.8.8.34 tel:0.94.4.8.8.34 (new package)
highlighting-kate-0.5.6.1 (new package)
resourcet-0.4.10.2 (new version)
securemem-0.1.3 (new package)
crypto-cipher-types-0.0.9 (new package)
cipher-aes-0.2.7 (new package)
cipher-rc4-0.1.4 (new package)
crypto-random-0.0.7 (new package)
cprng-aes-0.5.2 (new package)
crypto-numbers-0.2.3 (new package)
crypto-pubkey-0.2.4 (new package)
socks-0.5.4 (new package)
temporary-1.1.2.5 (new package)
text-stream-decode-0.1.0.5 (new package)
conduit-1.0.17.1 (new version)
http-client-conduit-0.2.0.1 (new package)
wl-pprint-text-1.1.0.2 (new package)
graphviz-2999.16.0.0 (new package)
x509-1.4.11 (new package)
x509-store-1.4.4 (new package)
x509-system-1.4.5 (new package)
x509-validation-1.5.0 (new package)
tls-1.2.6 (new package)
connection-0.2.1 (new package)
http-client-tls-0.2.1.1 (new package)
http-conduit-2.0.0.10 (new package)
xml-1.3.13 (new package)
texmath-0.6.6.1 (new package)
yaml-0.8.8.2 (reinstall) changes: conduit-1.1.1 -> 1.0.17.1, resourcet-1.1.2
-> 0.4.10.2
zip-archive-0.2.2.1 (new package)
pandoc-1.12.3.3 (new package)
Graphalyze-0.14.0.2 (new package)
SourceGraph-0.7.0.5 (new package)
cabal: The following packages are likely to be broken by the reinstalls:
stylish-haskell-0.5.10.0
scion-browser-0.3.1
persistent-template-1.3.1.3
persistent-sqlite-1.3.0.5
persistent-1.3.0.6
buildwrapper-0.8.0
dynamic-cabal-0.3.1
Use --force-reinstalls if you want to install anyway.
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