Idiomatic D?

[Matt Diesel]

Today I learnt D. I have a lot of experience with other 
languages, but I think D fills a gap. So far I've really liked 
it, having used C# and C a lot it feels right. I'm also pretty 
excited about some of the more powerful features.

I can teach myself a language no problem, but to make it useful 
it's always better to write it the way it was meant to be written.

Firstly, is there any good resource on what idiomatic D usage is? 
For instance Go has a huge page called Effective Go which tells 
you how you should use features, rather than what they are.

And secondly, I would be grateful if anyone could take a look at 
this very simple program and comment on how I'm using the 
language (ignoring the fact it's really simple and the lexer is 
rubbish). Just stuff like interface, class and variable naming 
and program structure.

Thanks a lot,

Matt