[bunderbunder]

I don't really want to get into a flamewar about static vs dynamic. I'm a polyglot, I use several languages with multiple flavors of type system, I think that most options have at least a couple things to recommend them.

However, the grandparent has a point: Java's type system makes static typing much more painful than it needs to be. I didn't start working in Java until fairly recently, and it was only then that I started to understand how many fans of dynamic languages could say that static typing mostly just gets in the way. But, if the only static language you've spent much time with is Java. . . now I get it. Java's type system mostly just gets in the way.

[meddlepal]

How does Java's type system get in the way?

[bunderbunder]

It's statically typed, but with basically no type inference (the diamond operator is something, I guess, but not much). So you end up putting a lot of time into manually managing types. That creates friction when writing code, since you need to remember the name of the return type of every method you call in order to keep the compiler happy. Worse, it creates friction when refactoring code, since any change that involves splitting or merging two types, or tweaking a method's return type, ends up forcing a multitude of edits to other files in order to propitiate the compiler. I've seen 100-file pull requests where only one of those file changes was actually interesting.

Then, to add insult to injury, its static type system is very weak. A combination of type erasure, a failure to unify arrays with generic types, and poor type checking in the reflection system means that Java's static typing doesn't give you particularly much help with writing well-factored code compared to most other modern high-level languages.

Speaking of generics, the compiler's handling of generics often leaves me feeling like I'm talking to the police station receptionist from Twin Peaks. Every time I have to explicitly pass "Foo.class" as an explicit argument when the compiler should already have all the information it needs to know what type of result I expect, I cry a little inside.

Long story short, if I could name a type system to be the poster child for useless bureaucratic work for the sake of work, it would be Java's.

[meddlepal]

Some fair points... some comments and one question:

1. Java 10 has type inference so that should improve your first point going forward to some degree. That said, I would also say type system syntax != type system.

2. Compared to what other modern high-level languages? Also slight changing of goal posts, but what other modern high-level language that has some market adoption?

3. Agree with passing `Foo.class` or type tokens around. Very annoying.

[stuaxo]

It's not powerful enough at the same time as being overly verbose.

After using python for a bit I came back to Java and tried to do all sorts of things that just were not easy without a lot of faff.

[passivepinetree]

What would you consider to be a good static typing system?

[bunderbunder]

C#'s, if you're looking for a Java-style language done right.

Objective-C's is also interesting, for one that makes some different design tradeoffs. Being optionally static with duck typing, for one.

Any ML variant, if you want to see how expressive a language can get when static typing is treated as a way for the compiler to work for you, not you working for the compiler.

[sattoshi]

ReasonML has it just right imho