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Re: Get mapM to be lazy for IO

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On 2018-12-13 09:52:45 -05, Barry Fishman wrote:
> On 2018-12-11 05:19:18 -08, kfjwheeler@gmail.com wrote:
>> I'm kind of a beginner when it comes to Haskell.  Specifically with
>> regards to IO.
>>
>> I'm tying to write a very simple program that asks the user to input
>> a list of words.  It gets words until the user enters "done".
>>
>> I'm getting close, but it's still asking for input after I enter
>> "done".  I can't seem to get mapM to be lazy in the way I want.
>
> IO can be lazy, but the order of actions needs to preserved, so that
> each putStrLn prompt precedes it's getLine.

Oops, I was wrong.  If I replace the:

   xs <- getWordList 1

with:

  xs <- take 3 `fmap` getWordList 1

the values continue to be read.  So the IO can't be read lazily as far
as I can tell.

--
Barry Fishman

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Thread

Get mapM to be lazy for IO kfjwheeler@gmail.com - 2018-12-11 05:19 -0800
  Re: Get mapM to be lazy for IO Mark Carroll <mtbc@bcs.org> - 2018-12-11 13:36 +0000
    Re: Get mapM to be lazy for IO Kaylen Wheeler <kfjwheeler@gmail.com> - 2018-12-12 17:52 -0800
      Re: Get mapM to be lazy for IO Paul Rubin <no.email@nospam.invalid> - 2018-12-12 19:29 -0800
    Re: Get mapM to be lazy for IO Kaylen Wheeler <kfjwheeler@gmail.com> - 2018-12-12 18:21 -0800
      Re: Get mapM to be lazy for IO Paul Rubin <no.email@nospam.invalid> - 2018-12-12 19:31 -0800
  Re: Get mapM to be lazy for IO Barry Fishman <barry@ecubist.org> - 2018-12-13 09:52 -0500
    Re: Get mapM to be lazy for IO Barry Fishman <barry@ecubist.org> - 2018-12-13 10:21 -0500
      Re: Get mapM to be lazy for IO Barry Fishman <barry@ecubist.org> - 2018-12-13 10:46 -0500

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