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Besides null being a potential type for any reference and causing a ton of issues I do not think most Java programmers regularly care about the lack of abstrac

Besides null being a potential type for any reference and causing a ton of issues I do not think most Java programmers regularly care about the lack of abstractions like higher-kinded or union types. Would be nice to have, but never have I felt like I needed them. Enum types didn't exist in Java when the Comparable interface was implemented. That's why some API's look old-school by comparison because newer language features didn't exist yet.

masklinn 11y ago
> I do not think most Java programmers regularly care about the lack of abstractions like higher-kinded or union types. Would be nice to have, but never have I felt like I needed them. That could be stated about pretty much every feature added since Java 1 really, it's not like the blub paradox has disappeared from our reality. How do you know that you wanted union types when you've never used a language which had them (and had features hindering such a conceptualisation, C-style enums are not really helpful there, even less so when extended the way Java did)
lmm 11y ago
> I do not think most Java programmers regularly care about the lack of abstractions like higher-kinded or union types. Would be nice to have, but never have I felt like I needed them. My counterargument would be the popularity of annotation-based libraries in Java. An annotation is basically a place where the official type system has proven inadequate.
- masklinn 11y ago
  That's not entirely true, part of annotation's use case is metasyntactic: codegen, code analysis and just plain structured/extractable comments.
stickfigure 11y ago
For an eye-opening experience, walk through the tour of Ceylon sometime. It has the most sophisticated implementation union & intersection types I've yet seen: http://ceylon-lang.org/documentation/1.1/tour/types/ http://ceylon-lang.org/documentation/1.1/tour/types/ Compared to union/intersection types, I find myself craving higher kinded types less frequently. I do feel the absence strongly, however, when I'm writing tools. I think the lack of higher kinded types manifests in the Java community as inferior libraries (eg ORMs) that require more manual-feeding of information via annotations or extra parameters to methods.
rbanffy 11y ago
> I do not think most Java programmers regularly care about the lack of abstractions like higher-kinded or union types. When you become used to a given language, you start to reason in its terms. A programmer who is used to Java is used to its shortcomings and will not miss Lisp macros or dynamic types.

masklinn 11y ago

> I do not think most Java programmers regularly care about the lack of abstractions like higher-kinded or union types. Would be nice to have, but never have I felt like I needed them. That could be stated about pretty much every feature added since Java 1 really, it's not like the blub paradox has disappeared from our reality. How do you know that you wanted union types when you've never used a language which had them (and had features hindering such a conceptualisation, C-style enums are not really helpful there, even less so when extended the way Java did)

lmm 11y ago

> I do not think most Java programmers regularly care about the lack of abstractions like higher-kinded or union types. Would be nice to have, but never have I felt like I needed them. My counterargument would be the popularity of annotation-based libraries in Java. An annotation is basically a place where the official type system has proven inadequate.

masklinn 11y ago
That's not entirely true, part of annotation's use case is metasyntactic: codegen, code analysis and just plain structured/extractable comments.

stickfigure 11y ago

For an eye-opening experience, walk through the tour of Ceylon sometime. It has the most sophisticated implementation union & intersection types I've yet seen: http://ceylon-lang.org/documentation/1.1/tour/types/ http://ceylon-lang.org/documentation/1.1/tour/types/ Compared to union/intersection types, I find myself craving higher kinded types less frequently. I do feel the absence strongly, however, when I'm writing tools. I think the lack of higher kinded types manifests in the Java community as inferior libraries (eg ORMs) that require more manual-feeding of information via annotations or extra parameters to methods.

rbanffy 11y ago

> I do not think most Java programmers regularly care about the lack of abstractions like higher-kinded or union types. When you become used to a given language, you start to reason in its terms. A programmer who is used to Java is used to its shortcomings and will not miss Lisp macros or dynamic types.