On Wed, May 21, 2014 at 9:11 AM, Adam Bergmark <adam@bergmark.nl> wrote:
As is, I don't find data-default to be useful, and decided to move away from it in fay for a number of reasons: [...]

I agree. Default is the bad kind of trivial: it gives you nothing, but in exchange takes away type inference and the ability to choose different defaults for varying circumstances. I wouldn't support adding it to base, and prefer to avoid packages that use it.