justicecoder

From Wikipedia:

In computer science, a preprocessor (or precompiler)[1] is a program that processes its input data to produce output that is used as input in another program. […], which is often used by some subsequent programs like compilers.

The emphasis is mine.

Both Typescript and SASS are examples of preprocessors.

By that logic, the C compiler would also be a preprocessor since it converts C code into assembly. Simply calling something a preprocessor just because its output is source code is not logically correct. The same applies to JPlus: the fact that it ultimately produces Java source code does not make it a preprocessor. Internally, it performs compiler-level processes such as AST generation, null-safety checks, and boilerplate code generation, so it should be regarded as a proper compiler.

This isn’t an accusation, but was this comment written with AI? There’s a glaring logical error here which I think a human would catch easily, but an LLM (which is just a natural language generator, not a logic processor) could possibly overlook.

Specifically, your arguments don’t really make a lot of sense. They’re also not targeted at my claim. It reads more like a defense of JPlus. To which I want to clarify, I merely took issue with the specific claim I quoted, I wasn’t trying to say there’s no point to JPlus. There’s no need to defend JPlus in general. So I’m going to dismiss runtime behaviors since that has nothing to do with the syntax.

Things can get confusing if the explanation is too long, so here’s a concise way to put it.

It’s not entirely clear whether Groovy includes 100% of Java syntax, but in my view, Groovy focuses on enhancing the language itself, addressing areas where it falls short compared to modern languages.

On the other hand, JPlus is similar to how TypeScript addresses JavaScript’s lack of type safety: it focuses on strengthening Java’s safety while improving developer convenience through features like boilerplate code generation. Importantly, JPlus code always compiles down to standard Java, which means it can be integrated seamlessly into existing Java projects without changing the build environment or toolchain.

In short:

Groovy: Focuses on enhancing the expressive power of Java, adding modern language features and syntactic flexibility.

JPlus: Focuses on enhancing language safety and developer convenience, while maintaining full compatibility with Java. This allows developers to adopt JPlus without worrying about breaking existing Java projects.

Kotlin is great for null-safety, but Kotlin isn’t a superset, you can’t just compile a java file with kotlin and have it work.

JPlus allows you to enforce null-safety without rewriting your existing Java code, which can be easier for teams working in legacy projects or who prefer staying in pure Java.

You say:

Groovy is not 100% identical

Then you say:

JPlus aims to keep Java syntax almost intact

Which implies that it is not 100% identical either.

So why do you apply that same argument against one but not the other? Seems like marketing bs.

As you mentioned, the phrasing might make it seem inconsistent. The key difference here is not whether they are “100% identical,” but the degree and nature of the changes.

Groovy introduces dynamic typing, optional syntax, runtime behaviors, and other language features that can fundamentally alter how Java code executes. Even if the code compiles, subtle differences in behavior can occur. In contrast, JPlus preserves nearly all standard Java syntax while only adding compile-time null-safety checks and boilerplate code generation. These changes have minimal impact on the execution of existing Java code and are primarily intended to improve safety and developer convenience.

Additionally, JPlus is currently developed based on Java 20 syntax, with added null-safety and boilerplate code generation features. Therefore, code up to Java 20 is fully compatible. Since future updates will support the latest Java syntax as well, the phrasing “almost identical” is used intentionally. In practice, JPlus will continue to be Java syntax + α.

Technically, neither language is “100% identical” to Java, but the practical impact is very different. Groovy can alter runtime behavior, whereas JPlus preserves existing behavior almost entirely while adding safety and developer convenience. This is not marketing exaggeration, but a reflection of the difference in the invasiveness of changes.

Kotlin isn’t a superset, you can’t just compile a java file with kotlin and have it work afaik. That seems to be the point here.

This is more like a preprocessor anyway, like SASS to CSS. The compiler spits out Java source code, not jvm bytecode.

Exactly, as you said, Kotlin isn’t a Java superset. you can’t just compile a Java file with Kotlin and have it work. JPlus works similarly in that it outputs standard Java source code rather than JVM bytecode.

However, JPlus is not merely a “preprocessor.” It actually parses Java source like a compiler, performs null-safety checks and boilerplate code generation on the generated parse tree, and finally produces standard Java code. In that sense, JPlus should be considered a compiler. The only difference is that its output is Java code; if the code generation step were extended to produce JVM bytecode directly, it could bypass the Java source entirely and generate bytecode straightaway.

The key point is that, just like TypeScript addresses JavaScript’s lack of type safety, JPlus fills in some of Java’s gaps. It allows you to keep almost all of your existing Java code while adding features like null-safety and automatic boilerplate generation, improving both safety and developer convenience.

There’s Groovy. Their examples use a bit different syntax, like a lack of semicolons, and Gradle might also give the wrong idea. But it’s fully compatible with Java source code iirc, just adds its own stuff on top and broadens the allowed syntax a bit.

Groovy is highly compatible with Java and most Java code runs in Groovy without changes. However, it’s not 100% identical. Groovy introduces dynamic typing, additional syntax, and runtime behaviors that can differ from Java. JPlus, on the other hand, aims to keep Java syntax almost intact while adding null-safety and boilerplate code generation making it easier to apply to existing Java projects without rewriting code

Might be useful to some, but the underlying assumption that “more features = better” is questionable in general.

You’re right. more features don’t always mean better. JPlus isn’t just about adding features; Our goal is to reduce boilerplate and enforce null-safety in existing Java code without rewriting it. Even when adding new functionality, JPlus avoids features that would be difficult for existing Java developers to adopt. All new features are designed to feel natural to Java, keeping the learning curve minimal so developers can use them intuitively without extra study. Its value comes from practical safety and developer convenience, rather than simply having more language features

Notably, there is currently no ‘superset’ language that keeps Java syntax almost intact

There’s groovy iirc.

Groovy is highly compatible with Java and most Java code runs in Groovy without changes. However, it’s not 100% identical. Groovy introduces dynamic typing, additional syntax, and runtime behaviors that can differ from Java. JPlus, on the other hand, aims to keep Java syntax almost intact while adding null-safety and boilerplate code generation making it easier to apply to existing Java projects without rewriting code

Isn’t kotlin a better option?

Kotlin is great for null-safety, but JPlus allows you to enforce null-safety without rewriting your existing Java code, which can be easier for teams working in legacy projects or who prefer staying in pure Java.