On Tue, Jun 30, 2015 at 11:25 AM, Neil Mitchell
To all the people who are worried about breakage, I can guarantee this will cause breakage. It's a sad fact, and certainly the main negative to this proposal. I was on the fence initially when hvr suggested this change to me, but was convinced by performance and correctness. Whether the Haskell community as a whole thinks that makes it worth it is why it's a proposal. If anything, I'm concerned by the lack of people saying -1, please don't break my code...
I'm not convinced by the performance argument. Most people don't need performance from the small amount of FilePath usage they have. Those who do can switch to a different package. Now correctness would be a good argument, but this proposal doesn't really add that much in that respect, it seems. I'm still on the fence, but leaning towards -1, but I'm not saying please don't break my code. My code will be fine, I'm around to fix it. I'm more worried about other people's code (that I might rely on), maintainers that have left, or aren't that responsive, newcomers reading old tutorials, people getting angry about needing more CPP/fixing more code on new GHC releases, etc. We're still breaking code on every new GHC release, and it seems the amount of breakage is only increasing. Erik