Java > Scala

[bearophile]

David Eagen:

> So, it's nearly twice as fast but still the slowest of the four.

I guess that a Python program too will be faster than the D code.

Your D code looks good enough now. The problem is that to create fast programs you need well tuned libraries and a good compiler back-end, and this requires lot of work and time. Currently steering too much D development efforts toward tuning is a bad idea because there are several more important issues, even design ones (like applying the already written patches present in GitHug).

Cosmetic matters about your code:

args[1 .. args.length]  ==>  args[1 .. $]
endsWith(hostName, "foo.com")  ==> hostName.endsWith("foo.com")

Now I suggest to compile your D program with:
- O -release -inline -profile
and run it on a smaller input (because it will run slower or much slower).

rename the profiling output files (otherwise they get corrupted, I don't know if this problem is in bugzilla), and profile it again with:
- O -release -profile

Taking a look at the profiler output will help find where the problems are. Maybe that profiling will generate material for a Bugzilla entry too.

If you also want to try disabling the GC in the inflationary phase of the program:

import core.memory: GC;
...
    GC.disable();
    foreach (arg; args[1 .. args.length])
...
    GC.enable();
    /* Sort the host names */
...

Bye,
bearophile