PolyConf

Credit

The polyconf.core.deepmerge module is a heavy refactor of gh://toumorokoshi/deepmerge. (More specifically, I based it on the tip of main at the time, which was commit 33a078ac7a29b63dfb91fea806cc6b96ede3fd23.) I don't want this library to have 3rd party dependencies, so I basically stripped the dynamic configurability of deepmerge, such that the behavior of always_merge() became the only behavior.

The keyword arguments are quite self-explanatory, so to concisely define the behavior, consider this snippet:

always_merger = Merger(
    type_strategies=[
        (list, "append"),
        (dict, "merge"),
        (set, "union"),
    ],
    fallback_strategies=["override"],
    type_conflict_strategies=["override"],
)

The refactor is heavy, indeed. At the time of this writing, cloc calculates it at only 22 lines of code. However, I still want to give credit where it's due because there are a couple lessons in recursion and fallback behavior that would have been painful to work out myself. It also serves as a reminder for future reference because if I ever reverse the moratorium on 3rd party libs, I'll happily depend on deepmerge directly.