System.exit(1) shouldn't be called at the end of the ScalaBuff run

[SandroGrzicic]

It isn't compatible with testing or programmatic access since it shuts down the whole JVM.

https://github.com/SandroGrzicic/ScalaBuff/pull/56#issuecomment-19856839

Proposed solution: throw an exception at end of execution if user specifies a "-debug" (or similar flag).

[robey]

In the unix world, the exit code is returned from main(), which is easy to test for, but java doesn't allow that, so (as far as I know) System.exit() is the only way.

I like @viktorklang 's idea: rename the current "main" to "run" (or something similar), and have it throw an exception if there were any errors. Then make a new "main" that does nothing but call "run", catch exceptions, and turn that into a System.exit. You can call "run" from the tests and verify that an exception was/was-not thrown. "main" can be called from the system executable.

[SandroGrzicic]

Great, that actually sounds reasonable and clean.

[SandroGrzicic]

I've done some tiny amount of work on this (exams.. I'll do more in a few days, along with the OSGi ticket) and so far the main/run solution seems nice.

I really need to overhaul the (new) run method, though, it's too big.

I've also noticed that we're working on one input file at a time. Adding .par on the main processing for loop increased the performance as measured by the PerformanceTest by approx. 2x. :) It's a totally unscientific and quick&dirty test and hopefully there won't be any concurrency issues (so far all unit tests check out). But it's one of the reasons that Scala is so awesome. :)

Forgot to reference the issue from the commit: https://github.com/SandroGrzicic/ScalaBuff/commit/3244493944849e4898e8e5f36af9b96c3802d6f5

I'll probably improve the current "boolean flag" return, it reminds me too much of C programs. :|

(although I hope @viktorklang likes my AtomicBoolean. ^^)