cafe-latte VS eff

Have you already evaluated cafe-latte?

This may interest you: cafe-latte. It's an implementation of CL's condition system (which has restarts) in Java.

Lack of macros makes nothing impossible, but also makes many things harder. I think of them as code generators, tiny compilers on a micro scale; they are invoked by the proper compiler during compilation phase, as opposed to runtime, allowing you to inject code that you'd otherwise need to inline by hand.

It's possible to write pretty complex things like control flow abstractions using just structures and functions/methods, e.g. a CL-esque condition system in Java which only uses classes, static methods, and Java lambdas[0] for its syntax. Possible, but also IMO ugly when compared to the CL counterpart, because the low-level but irrelevant details (such as instantiation via `new` or generics) are still presented to the programmer.

[0] https://github.com/phoe/cafe-latte

Condition system in Java: https://github.com/phoe/cafe-latte

phoe then said "Notice that no one mentions that this way they also managed to drag a lot of Lisp programmers about halfway back to C++."

If your language has closures, you can turn effect handlers into callbacks executed down the stack if needed. At least, this is how I hacked it in Python in eff library.