[Haskell-cafe] Why Maybe exists if there is Either?

Daniel Trstenjak daniel.trstenjak at gmail.com
Thu Jan 9 15:13:17 UTC 2014

Hi Vlatko,

On Thu, Jan 09, 2014 at 03:50:16PM +0100, Vlatko Basic wrote:
> I'm curious to find out what was the reasoning to make Maybe?
> What is the added value with introducing it?
> In which situations the above substitution does not hold?

If you just want to signalize a fail case without any additional
information, then a Maybe fits better than an Either, because
why should you need this bogus empty string?

How should you know that the string doesn't contain something relevant?


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