[dchichkov]

>> In summary, I think a lot of what we find "readable" depends on what we are used to.

I think a general rule is that source code readability is inverse to the amount of context information that one needs to remember in order to interpret and understand the code.

If you can look at the code at any place (and at any scale, ranging from a single line to the whole call graph), and without any context understand what is happening at this particular place - code is readable. And on the opposite, if you need to know a lot about the context of each particular line of code - code is unreadable.