[Haskell-cafe] Data.Binary suboptimal instance
andrewcoppin at btinternet.com
Fri May 22 16:23:04 EDT 2009
Henning Thielemann wrote:
> On Fri, 22 May 2009, Andrew Coppin wrote:
>> My first problem was quite simple. I want to write a program that
>> reads an item from the input file, processes it, writes it to the
>> output file, and repeats until the input file is empty. Data.Binary
>> doesn't appear to provide any obvious way to do this. You can't be in
>> the Get and Put monads simultaneously, and I can't figure out how to
>> interleave them.
> You can! - It's again time to point out that Put shouldn't be a monad,
> but a monoid. But as it is, Put is a Writer monad on top of the
> Builder monoid. Better use that Builder monoid directly.
Thanks for the tip. :-D
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