[RX14]

Crystal does the same as ruby for instance variable access, it's just that such methods are such an easy target for inlining by LLVM there's practically no performance penalty. The flexibility of gets and sets simply being method calls is very awesome and very worth it.

[vidarh]

It sounds like more substantial semantic differences then, as in the Ruby case the challenge with making it fast is that you can't take shortcuts like that without first verifying that there are no possible calls to any code that can have side effects like making changes to the receiver - you need to be prepared to "deoptimize" the code back to doing full method calls at any point, as in the general case you have no guarantee that the code will remain a simple getter/setter.