The Microsoft .NET Framework API¹ has a curiously named interface
ILogicalThreadAffinative. According to their naming standard, namely concatenating capitalized meaningful English words into a single string, this represents something which is “logical thread affinative” (and the prefix “I” is for “interface”, which is irrelevant to this question), or, how I read it, affinative to a logical thread.
While the meaning of the “logical thread” is clear to the user², I am curious what could the word affinative mean, and is this not an invented word at all. To me, it looks like a two-stage suffixal defivation:
affine (adj.) > ?affinate (adj.) > ?affinative (adj.),
but I cannot find either of the latter two words in any dictionary, or even Google. I have been in this business for 30 years, give or take a few, and never heard them. Also, as documented, the concept is nothing more than being simply affine to a logical thread; the entity having this property simply “sticks” to the logical thread and follows it as it spans physical threads³.
Is the word affinative (and/or affinate) is, well, a meaningful word? And if it is, how is it different from affine?
Update: From @ZebraFish's answer it appears the correct spelling of the adjective is affinitive, and, by extension, that my own use of affine (including this post) in the sense “exhibiting affinity” is probably not correct or, at the very least, is not the best word choice.
¹ For the inquisitive but uninitiated, the acronym API, or Application Programming Interface, in this context means a very general set of programming functions for anyone writing a program to use. Usually, at this scale, when such a set is designed for literally tens of millions of users, the API design passes a long, stringent, iterative review for consistency, well-defined behavior and, not the least, naming. I would not even bother asking this question if the case in point was a set of narrow purpose functions developed by a small project (I have seen much worse), but this one is a general-purpose interface to a very popular, flagship platform from a very large company. This is why I am in doubt.
² Understanding what is a (logical) thread is probably not essential here. Simply speaking, it is merely a programmed sequence of actions that is logically causal and continuous, but physically executes on different parts of a computer or even different computers at different times.
³ To give an analogy, suppose you read a Kindle book on your phone, put it down, then later open the same book on a tablet and continue reading where you left off. The page number where you stopped and then continued goes along with, or is affine (or “affinative”??) to the “logical thread” of reading the book.