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Today's Topics:
1. Re: Pattern Matching for record syntax (Jeon-Young Kang)
2. Re: Pattern Matching for record syntax (Imants Cekusins)
3. Re: Pattern Matching for record syntax (Magnus Therning)
4. Re: Pattern Matching for record syntax (Jeon-Young Kang)
5. stack issues (frantisek kocun)
6. Re: stack issues (frantisek kocun)
----------------------------------------------------------------------
Message: 1
Date: Thu, 7 Jan 2016 17:43:19 -0500
From: Jeon-Young Kang <jykan...@gmail.com>
To: The Haskell-Beginners Mailing List - Discussion of primarily
beginner-level topics related to Haskell <beginners@haskell.org>
Subject: Re: [Haskell-beginners] Pattern Matching for record syntax
Message-ID:
<calwtik-ewjv5y+19xo3+fpxbua-rmovy2iydxltptn+5yjc...@mail.gmail.com>
Content-Type: text/plain; charset="utf-8"
For pattern matching.. I implemented like this.
compareName a (Person name age)
| (a == name) = age
but, I got stuck how to apply pattern matching for the two lists.
i.e., both names and persons are lists.
I really appreciate your advice..
On Thu, Jan 7, 2016 at 5:37 PM, Imants Cekusins <ima...@gmail.com> wrote:
> > filter is only applicable to list, not "record syntax".
>
> but [Person] is the input, isn't it?
>
> > Do I need functor for this??
>
> no need to define new functor instance to filter over a list of records.
>
> but you could use fmap over list, yes
>
> _______________________________________________
> Beginners mailing list
> Beginners@haskell.org
> http://mail.haskell.org/cgi-bin/mailman/listinfo/beginners
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>
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Message: 2
Date: Thu, 7 Jan 2016 23:50:32 +0100
From: Imants Cekusins <ima...@gmail.com>
To: The Haskell-Beginners Mailing List - Discussion of primarily
beginner-level topics related to Haskell <beginners@haskell.org>
Subject: Re: [Haskell-beginners] Pattern Matching for record syntax
Message-ID:
<cap1qinbrdfc891bdulf8btjsehetbxvwy4blkgrsx+tffmk...@mail.gmail.com>
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Could you filter, then map? I'd try that instead of pattern matching.
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Message: 3
Date: Thu, 07 Jan 2016 23:51:59 +0100
From: Magnus Therning <mag...@therning.org>
To: The Haskell-Beginners Mailing List - Discussion of primarily
beginner-level topics related to Haskell <beginners@haskell.org>
Subject: Re: [Haskell-beginners] Pattern Matching for record syntax
Message-ID: <87wprlj94g....@therning.org>
Content-Type: text/plain; charset="us-ascii"
Jeon-Young Kang writes:
> For pattern matching.. I implemented like this.
>
> compareName a (Person name age)
> | (a == name) = age
>
> but, I got stuck how to apply pattern matching for the two lists.
> i.e., both names and persons are lists.
>
> I really appreciate your advice..
Something like this works:
map age $ filter (\ p -> (name p) `elem` names) persons
/M
--
Magnus Therning OpenPGP: 0x927912051716CE39
email: mag...@therning.org jabber: mag...@therning.org
twitter: magthe http://therning.org/magnus
Finagle's Fifth Law:
Always draw your curves, then plot your readings.
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Message: 4
Date: Thu, 7 Jan 2016 18:02:12 -0500
From: Jeon-Young Kang <jykan...@gmail.com>
To: The Haskell-Beginners Mailing List - Discussion of primarily
beginner-level topics related to Haskell <beginners@haskell.org>
Subject: Re: [Haskell-beginners] Pattern Matching for record syntax
Message-ID:
<CALWtiK_=sb0ar+qkabqrgb8dvo97owte7p45w2h5o8bwpau...@mail.gmail.com>
Content-Type: text/plain; charset="utf-8"
I figured out.. Thank you so much.
On Thu, Jan 7, 2016 at 5:51 PM, Magnus Therning <mag...@therning.org> wrote:
>
> Jeon-Young Kang writes:
>
> > For pattern matching.. I implemented like this.
> >
> > compareName a (Person name age)
> > | (a == name) = age
> >
> > but, I got stuck how to apply pattern matching for the two lists.
> > i.e., both names and persons are lists.
> >
> > I really appreciate your advice..
>
> Something like this works:
>
> map age $ filter (\ p -> (name p) `elem` names) persons
>
> /M
>
> --
> Magnus Therning OpenPGP: 0x927912051716CE39
> email: mag...@therning.org jabber: mag...@therning.org
> twitter: magthe http://therning.org/magnus
>
> Finagle's Fifth Law:
> Always draw your curves, then plot your readings.
>
> _______________________________________________
> Beginners mailing list
> Beginners@haskell.org
> http://mail.haskell.org/cgi-bin/mailman/listinfo/beginners
>
>
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Message: 5
Date: Thu, 7 Jan 2016 22:46:11 -0500
From: frantisek kocun <frantisek.ko...@gmail.com>
To: beginners@haskell.org
Subject: [Haskell-beginners] stack issues
Message-ID:
<CAMcUN70acPqgjLCTtVkKhoBR==qv4vz_vfva+nb-eqlnsyf...@mail.gmail.com>
Content-Type: text/plain; charset="utf-8"
Hi,
I'm new to cabal/stack. I want to use "stack build" to build my project.
I can not use latest gkt >= 0.14.2 because of
setup: The pkg-config package 'cairo' version >=1.2.0 is required but it
could
Neither can I now use older version gtk >=0.12.0 && < 0.13
While constructing the BuildPlan the following exceptions were encountered:
-- Failure when adding dependencies:
gtk: needed (>=0.12.0 && <0.13), 0.14.2 found (latest version
available)
needed for package: ships-0.1.0.0
What can i do? Thanks
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Message: 6
Date: Thu, 7 Jan 2016 23:13:36 -0500
From: frantisek kocun <frantisek.ko...@gmail.com>
To: beginners@haskell.org
Subject: Re: [Haskell-beginners] stack issues
Message-ID:
<camcun73sygdenpc0-um+qmwild2jdb0f2aenrbkbghg2row...@mail.gmail.com>
Content-Type: text/plain; charset="utf-8"
Found that gtk was not installed. So I did
brew install gtk
but I got different problem
[ 22 of 209] Compiling Graphics.UI.Gtk.Embedding.Plug (
.stack-work/dist/x86_64-osx/Cabal-1.22.5.0/build/Graphics/UI/Gtk/Embedding/Plug.hs,
.stack-work/dist/x86_64-osx/Cabal-1.22.5.0/build/Graphics/UI/Gtk/Embedding/Plug.o
)
Graphics/UI/Gtk/Embedding/Plug.chs:120:6:
Couldn't match expected type ?Ptr ()?
with actual type ?Maybe DrawWindow?
In the first argument of ?gtk_plug_new?, namely
?(fromNativeWindowId (fromMaybe nativeWindowIdNone socketId))?
In the second argument of ?($)?, namely
?gtk_plug_new
(fromNativeWindowId (fromMaybe nativeWindowIdNone socketId))?
On Thu, Jan 7, 2016 at 10:46 PM, frantisek kocun <frantisek.ko...@gmail.com>
wrote:
> Hi,
>
> I'm new to cabal/stack. I want to use "stack build" to build my project.
>
> I can not use latest gkt >= 0.14.2 because of
> setup: The pkg-config package 'cairo' version >=1.2.0 is required but
> it could
>
> Neither can I now use older version gtk >=0.12.0 && < 0.13
>
> While constructing the BuildPlan the following exceptions were encountered:
>
> -- Failure when adding dependencies:
>
> gtk: needed (>=0.12.0 && <0.13), 0.14.2 found (latest version
> available)
>
> needed for package: ships-0.1.0.0
>
>
>
> What can i do? Thanks
>
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