foreach iterator with closure

[Denis]

To keep this reply brief, I'll just summarize:

Lots of great takeaways from both of your posts, and a handful of 
topics you mentioned that I need to dig into further now. This is 
great (I too like D :)

I very much appreciate the extra insight into how things work and 
why certain design decisions were made: for me, this is essential 
for gaining fluency in a language.

Thanks again for all your help!
Denis