Re: [Haskell-cafe] Why Either = Left | Right instead of something like Result = Success | Failure

It's indeed arbitrary. Other common names are Inl and Inr (presumably standing for "inject left/right"). Some Haskell project do indeed use a more specific name. The advantage of using the generic Left/Right is reusability of library code. The particular name of the datatype and its constructors are competely arbitrary. The use of "Right" for "Success" is a handy pun -- the program returned "the right answer". HTH, / Thomas On 27 May 2010 15:25, Ionut G. Stan wrote:

Hi,

I was just wondering if there's any particular reason for which the two constructors of the Either data type are named Left and Right. I'm thinking that something like Success | Failure or Right | Wrong would have been a little better.

I've recently seen that Scala uses a similar convention for some error notifications so I'm starting to believe there's more background behind it than just an unfortunate naming.

Thanks, -- Ionuț G. Stan  |  http://igstan.ro _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe

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