2013/2/25 Michael Snoyman <michael@snoyman.com>

At that point, we've now made two changes to REWRITE rules:

1. They can takes a new ALWAYS parameters.
2. There's a new, special identifier currentLocation available.

What would be the advantage is of that approach versus introducing a single new REWRITE_WITH_LOCATION pragma?

Just a remark: 'currentLocation' is not a function (it's a special keyword) but behaves like one - it returns some kind of value. But it's not referentially transparent - it returns a different value depending on where it's used. This is something that I really don't expect from Haskell. So having it return `IO Location` seems therefore much better option. And if someone really wants to get the location as a pure value, (s)he can simply wrap it with `unsafePerformIO`, which signals code readers to be careful with that part.

Best regards,

Petr