Comments on Java Numerics

[David G. Hough at validgh]

> What we wanted with Java is that you could write a numeric program
> and send it to someone else after testing it and know it would behave,
> for them, the same way it behaved for you.  Otherwise there is no way
> to ever finish "testing" a program.  The ability to write once and test
> once
> and have confidence everywhere is the KEY idea of Java...

And the slogan should not be just "write once run anywhere" but

"Write once, TEST ONCE, run anywhere"

This corresponds to the notion (advanced about operating systems and
other complex systems) that if the interfaces are sufficiently well
defined, then you can freely change the implementations underneath the
interfaces without necessarily having to retest the whole system to 
determine if your changes affect some should-be unrelated component
elsewhere.    It's a noble vision, even if somewhat distant from most
current practice, and extremely difficult to achieve when the interfaces
themselves are changing rapidly in an immature industry.