Re: [Haskell-cafe] Call for discussion: OverloadedLists extension

Roman Cheplyaka wrote:

* Heinrich Apfelmus [2012-09-23 10:51:26+0200]

...

Unfortunately, making literals polymorphic does not always achieve the desired effect of reducing syntax. In fact, they can instead increase syntax! In other words, I would like to point out that there is a trade-off involved: is it worth introducing a small syntactic reduction at the cost of both a small additional conceptual complexity and some syntactic enlargement elsewhere?

Can't you just disable the extension when you realise that it makes your life harder?

I thought so, too, but there is actually a "social" catch. Namely, a library/DSL can be designed with that extension in mind and advocate its use. The [scotty][] library is an example for this. In particular, the RoutePattern type is made an instance of IsString and the example code uses it extensively. If I want to disable the extension, I have to translate the example code first. When learning a library for the first time, this can be rather confusing. [scotty]: http://hackage.haskell.org/package/scotty Best regards, Heinrich Apfelmus -- http://apfelmus.nfshost.com