Oh, I also disliked implicit conversions a lot. I considered them a wart at some point. Made everything hard to read and reason about.
Almost every other way of "extending" a type would have worked better in practice eg. Xtend’s Extension Methods.
Almost every other way of "extending" a type would have worked better in practice eg. Xtend’s Extension Methods.
It's not like Scala developers didn't know extension methods before designing implicits.
Instead, they tried to come up with a more useful, principled way, which also covers a lot of the stuff which is hardcoded and implemented ad-hoc in other languages (like implicit conversions in Java).
In the end, I think they made the right call:
- Implicit parameters are the basis for abstractions which unify the "strategy pattern" of OO languages with FP's typeclasses,
- implicit classes provide extension methods, but are better in pretty much every regard (higher reusability, less error prone) and
- implicit conversions cover the ad-hoc conversions everyone takes for granted, without having to hard-code these hacks into the language (e. g. don't like Java's/C#'s/... implicit convert-everything-to-String conversion? Don't import it in Scala).