Comment by chasd00
9 hours ago
This was one of the promises of Java. You write your application and then you get a virtual machine (JVM). As time goes on you only maintain the virtual machine while the application remains the same.
9 hours ago
This was one of the promises of Java. You write your application and then you get a virtual machine (JVM). As time goes on you only maintain the virtual machine while the application remains the same.
"only" is doing some heavy lifting here. A modern VM is probably more complex than a kernel.
The funny thing happened and verified this promise. There were several architects working on IBM System Object Model (SOM). In 1996-1997 many good things ended, and SOM was terminated. But the work was so good that two architects did not stop and wrote the book: Putting Metaclasses to Work (1998). That book has got reference implementation in Java. So we have IBM SOM as closed source binary and we have Java source codes.
IBM SOM executes on Windows 10. I have checked Visual Age for C++ Direct2SOM extensions, OpenDoc for Windows. Very good. 32-bit i386, but otherwise runnable, usable.
And Java is hard to build, hard to execute on modern Java toolkit. Java seemingly had no List, and authors made their own List, but when Java also got its List, that breaks the build. When building problems are resolved, runtime problems come. Original Java was seemingly fine with Property key being object, but modern Java only wants strings. And Property-based dictionaries are all around. PMtW is about building VMT, and there is multiple class inheritance in PMtW model, not matching Java's comparably limited OOP. So PMtW is building dictionaries for methods to support what is described in book, and foundational Java class is malfunctioning.
I did not finish this road, don't know so what does it take after all to run Java code from 1998 on modern Java toolkit. So far looks pathetic compared to Win32 programming.