{Keyword,Map}.merge_new/2

[Austin Ziegler]

This isn’t something I’ve needed often, but every time I have needed
it, I have to look up the docs of merge/3. Basically, I want to merge
two keyword lists or maps but only add new values (do not replace old
values). I know that this is just:

```elixir
Keyword.merge(left, right, fn _k, lv, _rv -> lv end)
```

But I have to look it up in the docs every time; I think that adding
the new name here would be good UX. Alternatively, the accepted values
for `merge/3` could be changed to accept a conflict function or an
atom indicating the merge strategy. This is, IMO, worse UX because it
would also be incompatible with older versions (delaying its adoption
by libraries).

-a
--
Austin Ziegler • halos...@gmail.com • aus...@halostatue.ca
http://www.halostatue.ca/ • http://twitter.com/halostatue

[José Valim]

I believe the most efficient way to do what you want is to reverse the order of arguments and call Map.merge/2 and Keyword.merge/2.

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