[Haskell-beginners] Beginners Digest, Vol 89, Issue 38 How to define a simple function
Francisco Gutierrez
fgutiers2002 at yahoo.com
Mon Nov 23 23:55:40 UTC 2015
Dear sirs:I am defining a function halve, that breaks a list in two halfs. But I always get an error. Below is my code. What am I doing wrong?Thanks!halve xs = [take (floor (longitud/2)), drop (floor (longitud/2))] where longitud = length xs
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Sent: Saturday, November 21, 2015 8:21 PM
Subject: Beginners Digest, Vol 89, Issue 38
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Today's Topics:
1. Re: Warning: Tab Character (Dan Stromberg)
2. Re: Warning: Tab Character (Jeon-Young Kang)
3. Re: Warning: Tab Character (Thomas Jakway)
----------------------------------------------------------------------
Message: 1
Date: Sat, 21 Nov 2015 16:44:21 -0800
From: Dan Stromberg <strombrg at gmail.com>
To: The Haskell-Beginners Mailing List - Discussion of primarily
beginner-level topics related to Haskell <beginners at haskell.org>
Subject: Re: [Haskell-beginners] Warning: Tab Character
Message-ID:
<CAOvKW55oxCcEhtqppC0bXQZjOEEv5vcYnBTWHaj9C5vhhm7g+w at mail.gmail.com>
Content-Type: text/plain; charset="utf-8"
I believe the first version of make required tabs, but some subsequent
versions have relaxed that requirement to make things easier.
Here's an example on a Linux Mint system (the 20's are of course spaces) :
$ od -cx < Makefile
cmd output started 2015 Sat Nov 21 04:39:47 PM PST
0000000 \n g o : \n . / t \n \n
670a 3a6f 200a 2020 2e20 742f 0a0a
0000016
above cmd output done 2015 Sat Nov 21 04:39:47 PM PST
dstromberg at dell-inspiron:/var/tmp/make-tabs i686-pc-linux-gnu 25234
$ make
cmd output started 2015 Sat Nov 21 04:39:48 PM PST
Makefile:3: *** missing separator. Stop.
above cmd output done 2015 Sat Nov 21 04:39:48 PM PST
dstromberg at dell-inspiron:/var/tmp/make-tabs i686-pc-linux-gnu 25234
$ make --version
cmd output started 2015 Sat Nov 21 04:39:53 PM PST
GNU Make 3.81
Copyright (C) 2006 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.
There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A
PARTICULAR PURPOSE.
This program built for i686-pc-linux-gnu
above cmd output done 2015 Sat Nov 21 04:39:53 PM PST
dstromberg at dell-inspiron:/var/tmp/make-tabs i686-pc-linux-gnu 25234
I'll add that vim's Makefile syntax highlighting puts the space-indented
line in red, suggesting an error. Changing the spaces to a single tab
makes the red go away.
HTH
On Sat, Nov 21, 2015 at 3:34 PM, Thomas Jakway <tjakway at nyu.edu> wrote:
> Why would make require tabs...?
> Admittedly it's been a long time since I've written any makefiles by hand
> but I always use spaces instead of tabs and have never had any problems.
>
> On Nov 21, 2015 6:01 PM, David Moberg <kaddkaka at gmail.com> wrote:
> >
> > Have you found "soft tabs"? That option will make TextMate use spaces
> instead of tab characters. Read 4.11 "Using Spaces Instead of Tabs" in Dan
> Strombergs link for instrucitons.
> >
> > 2015-11-21 21:36 GMT+01:00 Jeon-Young Kang <jykang22 at gmail.com>:
> >>
> >> I've tried to choose "instead of spaces". But there is no option of
> mine (Textmate 2 beta).
> >>
> >> On Sat, Nov 21, 2015 at 3:14 PM, Dan Stromberg <strombrg at gmail.com>
> wrote:
> >>>
> >>>
> >>> Perhaps enable soft tabs?
> >>> https://manual.macromates.com/en/working_with_text
> >>>
> >>> This is an issue in Python too (at least from PEP8's perspective) -
> but note that many "make" programs require tabs instead of spaces.
> >>>
> >>> On Sat, Nov 21, 2015 at 11:13 AM, Jeon-Young Kang <jykang22 at gmail.com>
> wrote:
> >>>>
> >>>> Hello everyone.
> >>>>
> >>>>
> >>>> I am a newbie of Haskell, using Textmate on mac.
> >>>>
> >>>>
> >>>> I got the following warning. How can I fix it?
> >>>>
> >>>>
> >>>> Warning:
> >>>>
> >>>> Tab character
> >>>>
> >>>> Ok, modules loaded: Main.
> >>>>
> >>>>
> >>>>
> >>>> Sincerely,
> >>>> Young
> >>>>
> >>>> _______________________________________________
> >>>> Beginners mailing list
> >>>> Beginners at haskell.org
> >>>> http://mail.haskell.org/cgi-bin/mailman/listinfo/beginners
> >>>>
> >>>
> >>>
> >>>
> >>> --
> >>> Dan Stromberg
> >>>
> >>> _______________________________________________
> >>> Beginners mailing list
> >>> Beginners at haskell.org
> >>> http://mail.haskell.org/cgi-bin/mailman/listinfo/beginners
> >>>
> >>
> >>
> >>
> >> --
> >> Department of Geography
> >> State University of New York at Buffalo
> >>
> >> jykang22 at gmail.com
> >>
> >> Jeon-Young Kang
> >>
> >> _______________________________________________
> >> Beginners mailing list
> >> Beginners at haskell.org
> >> http://mail.haskell.org/cgi-bin/mailman/listinfo/beginners
> >>
> >
> _______________________________________________
> Beginners mailing list
> Beginners at haskell.org
> http://mail.haskell.org/cgi-bin/mailman/listinfo/beginners
>
--
Dan Stromberg
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Message: 2
Date: Sat, 21 Nov 2015 20:03:08 -0500
From: Jeon-Young Kang <jykang22 at gmail.com>
To: The Haskell-Beginners Mailing List - Discussion of primarily
beginner-level topics related to Haskell <beginners at haskell.org>
Subject: Re: [Haskell-beginners] Warning: Tab Character
Message-ID:
<CALWtiK8DqDr292Bb=J7rEa8unXBrRTt6++HSSm82DuZjY6miTQ at mail.gmail.com>
Content-Type: text/plain; charset="utf-8"
Thanks! I figured out.
On Sat, Nov 21, 2015 at 7:44 PM, Dan Stromberg <strombrg at gmail.com> wrote:
>
> I believe the first version of make required tabs, but some subsequent
> versions have relaxed that requirement to make things easier.
>
> Here's an example on a Linux Mint system (the 20's are of course spaces) :
> $ od -cx < Makefile
> cmd output started 2015 Sat Nov 21 04:39:47 PM PST
> 0000000 \n g o : \n . / t \n \n
> 670a 3a6f 200a 2020 2e20 742f 0a0a
> 0000016
> above cmd output done 2015 Sat Nov 21 04:39:47 PM PST
> dstromberg at dell-inspiron:/var/tmp/make-tabs i686-pc-linux-gnu 25234
>
> $ make
> cmd output started 2015 Sat Nov 21 04:39:48 PM PST
> Makefile:3: *** missing separator. Stop.
> above cmd output done 2015 Sat Nov 21 04:39:48 PM PST
> dstromberg at dell-inspiron:/var/tmp/make-tabs i686-pc-linux-gnu 25234
>
> $ make --version
> cmd output started 2015 Sat Nov 21 04:39:53 PM PST
> GNU Make 3.81
> Copyright (C) 2006 Free Software Foundation, Inc.
> This is free software; see the source for copying conditions.
> There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A
> PARTICULAR PURPOSE.
>
> This program built for i686-pc-linux-gnu
> above cmd output done 2015 Sat Nov 21 04:39:53 PM PST
> dstromberg at dell-inspiron:/var/tmp/make-tabs i686-pc-linux-gnu 25234
>
>
> I'll add that vim's Makefile syntax highlighting puts the space-indented
> line in red, suggesting an error. Changing the spaces to a single tab
> makes the red go away.
>
> HTH
>
> On Sat, Nov 21, 2015 at 3:34 PM, Thomas Jakway <tjakway at nyu.edu> wrote:
>
>> Why would make require tabs...?
>> Admittedly it's been a long time since I've written any makefiles by hand
>> but I always use spaces instead of tabs and have never had any problems.
>>
>> On Nov 21, 2015 6:01 PM, David Moberg <kaddkaka at gmail.com> wrote:
>> >
>> > Have you found "soft tabs"? That option will make TextMate use spaces
>> instead of tab characters. Read 4.11 "Using Spaces Instead of Tabs" in Dan
>> Strombergs link for instrucitons.
>> >
>> > 2015-11-21 21:36 GMT+01:00 Jeon-Young Kang <jykang22 at gmail.com>:
>> >>
>> >> I've tried to choose "instead of spaces". But there is no option of
>> mine (Textmate 2 beta).
>> >>
>> >> On Sat, Nov 21, 2015 at 3:14 PM, Dan Stromberg <strombrg at gmail.com>
>> wrote:
>> >>>
>> >>>
>> >>> Perhaps enable soft tabs?
>> >>> https://manual.macromates.com/en/working_with_text
>> >>>
>> >>> This is an issue in Python too (at least from PEP8's perspective) -
>> but note that many "make" programs require tabs instead of spaces.
>> >>>
>> >>> On Sat, Nov 21, 2015 at 11:13 AM, Jeon-Young Kang <jykang22 at gmail.com>
>> wrote:
>> >>>>
>> >>>> Hello everyone.
>> >>>>
>> >>>>
>> >>>> I am a newbie of Haskell, using Textmate on mac.
>> >>>>
>> >>>>
>> >>>> I got the following warning. How can I fix it?
>> >>>>
>> >>>>
>> >>>> Warning:
>> >>>>
>> >>>> Tab character
>> >>>>
>> >>>> Ok, modules loaded: Main.
>> >>>>
>> >>>>
>> >>>>
>> >>>> Sincerely,
>> >>>> Young
>> >>>>
>> >>>> _______________________________________________
>> >>>> Beginners mailing list
>> >>>> Beginners at haskell.org
>> >>>> http://mail.haskell.org/cgi-bin/mailman/listinfo/beginners
>> >>>>
>> >>>
>> >>>
>> >>>
>> >>> --
>> >>> Dan Stromberg
>> >>>
>> >>> _______________________________________________
>> >>> Beginners mailing list
>> >>> Beginners at haskell.org
>> >>> http://mail.haskell.org/cgi-bin/mailman/listinfo/beginners
>> >>>
>> >>
>> >>
>> >>
>> >> --
>> >> Department of Geography
>> >> State University of New York at Buffalo
>> >>
>> >> jykang22 at gmail.com
>> >>
>> >> Jeon-Young Kang
>> >>
>> >> _______________________________________________
>> >> Beginners mailing list
>> >> Beginners at haskell.org
>> >> http://mail.haskell.org/cgi-bin/mailman/listinfo/beginners
>> >>
>> >
>> _______________________________________________
>> Beginners mailing list
>> Beginners at haskell.org
>> http://mail.haskell.org/cgi-bin/mailman/listinfo/beginners
>>
>
>
>
> --
> Dan Stromberg
>
> _______________________________________________
> Beginners mailing list
> Beginners at haskell.org
> http://mail.haskell.org/cgi-bin/mailman/listinfo/beginners
>
>
--
Department of Geography
State University of New York at Buffalo
jykang22 at gmail.com
Jeon-Young Kang
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------------------------------
Message: 3
Date: Sat, 21 Nov 2015 20:22:04 -0500
From: Thomas Jakway <tjakway at nyu.edu>
To: The Haskell-Beginners Mailing List - Discussion of primarily
beginner-level topics related to Haskell <beginners at haskell.org>
Subject: Re: [Haskell-beginners] Warning: Tab Character
Message-ID: <66118521-5ef8-4d50-b8dc-d65a38dd9620 at email.android.com>
Content-Type: text/plain; charset=utf-8
Huh, cool. I had no idea. Thanks!
On Nov 21, 2015 7:44 PM, Dan Stromberg <strombrg at gmail.com> wrote:
>
>
> I believe the first version of make required tabs, but some subsequent versions have relaxed that requirement to make things easier.
>
> Here's an example on a Linux Mint system (the 20's are of course spaces) :
> $ od -cx < Makefile
> cmd output started 2015 Sat Nov 21 04:39:47 PM PST
> 0000000? \n?? g?? o?? :? \n?????????????????? .?? /?? t? \n? \n
> ?????????? 670a??? 3a6f??? 200a??? 2020??? 2e20??? 742f??? 0a0a
> 0000016
> above cmd output done??? 2015 Sat Nov 21 04:39:47 PM PST
> dstromberg at dell-inspiron:/var/tmp/make-tabs i686-pc-linux-gnu 25234
>
> $ make
> cmd output started 2015 Sat Nov 21 04:39:48 PM PST
> Makefile:3: *** missing separator.? Stop.
> above cmd output done??? 2015 Sat Nov 21 04:39:48 PM PST
> dstromberg at dell-inspiron:/var/tmp/make-tabs i686-pc-linux-gnu 25234
>
> $ make --version
> cmd output started 2015 Sat Nov 21 04:39:53 PM PST
> GNU Make 3.81
> Copyright (C) 2006? Free Software Foundation, Inc.
> This is free software; see the source for copying conditions.
> There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A
> PARTICULAR PURPOSE.
>
> This program built for i686-pc-linux-gnu
> above cmd output done??? 2015 Sat Nov 21 04:39:53 PM PST
> dstromberg at dell-inspiron:/var/tmp/make-tabs i686-pc-linux-gnu 25234
>
>
> I'll add that vim's Makefile syntax highlighting puts the space-indented line in red, suggesting an error.? Changing the spaces to a single tab makes the red go away.
>
> HTH
>
> On Sat, Nov 21, 2015 at 3:34 PM, Thomas Jakway <tjakway at nyu.edu> wrote:
>>
>> Why would make require tabs...?
>> Admittedly it's been a long time since I've written any makefiles by hand but I always use spaces instead of tabs and have never had any problems.
>>
>> On Nov 21, 2015 6:01 PM, David Moberg <kaddkaka at gmail.com> wrote:
>> >
>> > Have you found "soft tabs"? That option will make?TextMate use spaces instead of tab characters. Read?4.11 "Using Spaces Instead of Tabs" in Dan Strombergs link for instrucitons.
>> >
>> > 2015-11-21 21:36 GMT+01:00 Jeon-Young Kang <jykang22 at gmail.com>:
>> >>
>> >> I've tried to choose "instead of spaces". But there is no option of mine (Textmate 2 beta).
>> >>
>> >> On Sat, Nov 21, 2015 at 3:14 PM, Dan Stromberg <strombrg at gmail.com> wrote:
>> >>>
>> >>>
>> >>> Perhaps enable soft tabs?
>> >>> https://manual.macromates.com/en/working_with_text
>> >>>
>> >>> This is an issue in Python too (at least from PEP8's perspective) - but note that many "make" programs require tabs instead of spaces.
>> >>>
>> >>> On Sat, Nov 21, 2015 at 11:13 AM, Jeon-Young Kang <jykang22 at gmail.com> wrote:
>> >>>>
>> >>>> Hello everyone.
>> >>>>
>> >>>>
>> >>>> I am a newbie of Haskell, using Textmate on mac.
>> >>>>
>> >>>>
>> >>>> I got the following warning. How can I fix it?
>> >>>>
>> >>>>
>> >>>> Warning:
>> >>>>
>> >>>> ? ? Tab character
>> >>>>
>> >>>> Ok, modules loaded: Main.
>> >>>>
>> >>>>
>> >>>>
>> >>>> Sincerely,
>> >>>> Young
>> >>>>
>> >>>> _______________________________________________
>> >>>> Beginners mailing list
>> >>>> Beginners at haskell.org
>> >>>> http://mail.haskell.org/cgi-bin/mailman/listinfo/beginners
>> >>>>
>> >>>
>> >>>
>> >>>
>> >>> --
>> >>> Dan Stromberg
>> >>>
>> >>> _______________________________________________
>> >>> Beginners mailing list
>> >>> Beginners at haskell.org
>> >>> http://mail.haskell.org/cgi-bin/mailman/listinfo/beginners
>> >>>
>> >>
>> >>
>> >>
>> >> --
>> >> Department of Geography
>> >> State University of New York at Buffalo
>> >>
>> >> jykang22 at gmail.com
>> >> ?
>> >> Jeon-Young Kang
>> >>
>> >> _______________________________________________
>> >> Beginners mailing list
>> >> Beginners at haskell.org
>> >> http://mail.haskell.org/cgi-bin/mailman/listinfo/beginners
>> >>
>> >
>> _______________________________________________
>> Beginners mailing list
>> Beginners at haskell.org
>> http://mail.haskell.org/cgi-bin/mailman/listinfo/beginners
>
>
>
>
> --
> Dan Stromberg
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