The sort of elliptical utterances without focus above are common and well known linguistics. Discourse analysis (DA) is the branch of linguistics that deals with spoken conversation. In DA, elliptical statements are a common element in conversations among eople who are friends or who at least share a common context and jargon. With so much common knowledge, speakers only have to say the minimal new information needed to get the idea across. Transcripts of spoken conversation among friends seem almost hopelessly illiterate to those outside their context, but the conversations are actually very efficient for those in the know.

What this tells me about the chatterbox is that people really do treat it as chatter, as a written version of a spoken conversation. And as you say, there is a fascinating deviation from the spoken paradigm when people inject detailed perl code or site references. Such detailed information probably could not be remebered easily in spoken conversation, but it works well here.