(4) Thanks for criticizing my bad coding style (using map in a void context). I am digging into the link to find out why I should avoid to use this style... :)

Don't be too hard on yourself for this one. Void map/grep have been argued over for years in the perl community. Some don't see a problem with it, others do. Definitely look into the issue and decide for yourself what is right.

I'm personally neutral on void map. I use foreach in most cases where a void map could be used, because I think it more clearly expresses the intent of the code. However, I would have no problem using a void map if I thought it made things more readable.

You might like to check out this nice article on void map