Have you seen a function declared like this?

def foo a, **b
  ...
end

I understand that a single * is the splat operator. What does ** mean?

Possible Duplicate:
What is the !! operator in JavaScript?
What does !! (double exclamation point) mean?

I am going through some custom JavaScript code at my workplace and I am not able to understand the following construct.

var myThemeKey = (!!$('row') && $('row').hasClassName('green-theme')) ? 'green' : 'white';

I understand everything on the above line except !! operator. I assume that it is a NOT operator and NOT of NOT is the original value but why would someone do a NOT of NOT?

Can someone please help me understand what is happening on the above line of code?

What does this mean in Python:

sock.recvfrom(2**16)

I know what sock is, and I get the gist of the recvfrom function, but what the heck is 2**16? Specifically, the two asterisk/double asterisk operator?

(english keywords, because it's hard to search for this: times-times star-star asterisk-asterisk double-times double-star double-asterisk operator)

Possible Duplicate:
What is the “double tilde” (~~) operator in JavaScript?

I found this snip of code in a node.js library's source. What effect does ~~ have on the input variable?

inArray[3] = ~~input;

It's also used in other ways:

return ~~ ((a - b) / 864e5 / 7 + 1.5);

Possible Duplicates:
Lamda Explanation and what it is as well as a good example
What is the => token called?

I have seen this code:

myContext.SomeEntities.Single(x => x.code == code);  

And I don´t know what does the => operator do.

Every search on google about the operator returns no results.

Thank you.