The phrase doins has many context specific meanings.
It was first derived from the question: what are you doing?, where it was condensed into: whats doin?, until finally landing on the simple and concise: doins? (see example 1). As you can see this neologism is the product of years of precise cultural refinement.
It is has been further generalised simply as a greeting that can be uttered without the expectation of an answer. (see example 2)
Doins can also be used elegantly to refer to other peoples behaviour (what they're doing) (see example 3)
Finally, the meaning of doins, when appropriate, can be extended to events where human interaction is superfluous. Essentially, anything that is happening could be the doins, the only requisite being that the doins is happening in time, because do is a verb, and requires change. In this context, the specific, enlightened meaning of doins may only be deciphered by a potent adjective proceeding it. (see examples 4 and 5)
Example 1
Person 1: "doins"
Person 2: "not much, doins with you?"
Person 1: "you know, just the usual doins"
Example 2
Person 1: doins!
Person 2: (*gives hug while sobbing*) "you have no idea how good it is to see you."
Example 3 (In an academic context)
"Freuds doins was to uncover all of our doins: the most human doins, those doins done both consciously and unconsciously."
Example 4 (in the context of intellectual sparring)
Person 1: "Einstien famously declared that no doins can be done faster than the speed of light"
Person 2: "I think you'll find that its all relative to the velocity of those other doins"
Person 1: "the velocity of those doins will dilate any temporal doins therefore rendering the relative doins, as measured from either doins, as travelling at less then the speed of light"
Person 2:"wow you really know your doins"
Example 5 (in an existential context)
"i wonder what the meaning of all these cosmological doins are"