cafe-latte VS excoptional

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++."

> I mean Scala because I guess it actually has it, but worth pointing out it's like 30 LOC to define one for JS, depending on how many convenience methods you want.

Here's one I wrote: https://github.com/sbernheim4/excoptional

I fully believe it to be one of the best Option implementations in JS/TS

https://github.com/sbernheim4/excoptional is an option object for js/ts

One benefit to keeping your value wrapped in a Maybe is that as you transform and manipulate the value and pass it around in your system, you leave it up to the last place in your system that uses the value to define the fallback value in the case of a None rather than defining a fallback value part way through and establish a convention that the fallback value means nothing was found at some other part of your system.

Another benefit to using Maybes is that you avoid the rigamarole of null checks at every call site where you want to use the value. If you have a function that returns null or a value, whenever you call that function you'll always have to add an if guard to validate it's not null. If it is, that function itself may return null, and callers to it will again have to implement the same check.

I wrote a JS implementation of the Option object and the readme has lots of specific examples about these benefits: https://github.com/sbernheim4/excoptional