Add a get_or_add method to Dictionary

[aaronfranke]

Implements this proposal and closes godotengine/godot-proposals#7059

[ajreckof]

The implementation is quite simple and in line with other dictionary functions. I'm just not sure about the name but I can't find a better one and python setDefault is even worse so this might be the best name😓

[RandomShaper]

My issue with get_or_set_default() is that it can be read as "get or set-default" and "get-or-set default." I'd say it's intended to be the former. get_ensuring_default() sounds better to me.

[aaronfranke]

I am good with either of the proposed names, none seems obviously better to me.

Really, it's more like "(get) or ((set and get) default)".

[RandomShaper]

Don't you like get_ensuring_default() more the more you read it? 😁

[AThousandShips]

I think get_ensuring_default() risks seeming like it always sets it, unsure how to state it clearly

[RandomShaper]

At this point I don't think the full behavior of the method can be summarized enough without leaving some thought to the user. In the defense of get_ensuring_default() I'll say that the "ensuring default," idea can't really mean anything else than "return if the key exists, otherwise set first," because there's already set().

[Repiteo]

What about ensure_key_then_get()? This makes the order of operations clear, as you're retrieving the value at the specified key regardless; if the key already exists, you just get the stored value — if the key didn't exist, you ensure it does via a default value, then you retrieve said default value

[Iniquitatis]

How about get_or_add or something along these lines?

[RandomShaper]

How about get_or_add or something along these lines?

I support that. Just let's be sure that Dictionary's jargon has room for "add"; in other words, it's not already using "insert" or the like for the same meaning.

[ajreckof]

No function use either of them yet and doc use both even in the same sentence like so :

So I would say either add or insert is okay I'm more accustomed to insert for dictionaries but this might just be a personal thing

[RandomShaper]

Maybe "insert" is more used in Godot containers in general.

get_or_insert() then?

[SysError99]

We should instead use what similar languages were offering, in this case set_default is a great candidate since it's very similar to Python.

https://docs.python.org/2/library/stdtypes.html

If this PR gets merged successfully, I'll try to cherry pick this to 3.x

[ajreckof]

I really don't like the Python set_default as it is really unclear on what it does

[peterhoglund]

I read get_or_set_deafault as getting or setting the default. I also agree Python's set_default is bad since it doesn't explain what is happening. What about just get_or_set?

[aaronfranke]

@RandomShaper "Insert" is usually associated with some kind of order, like with Array.insert(), so I would prefer to not use that terminology here. This method does not affect the order, if anything is added then it always goes to the "end".

[RandomShaper]

Back to get_or_add(), then?

[peterhoglund]

Sorry, I didn't see get_or_add() was suggested. I like it since it's obvious what it does. get_or_insert() is equally good imo, but since get_or_add is shorter it wins for me.

[akien-mga]

I think there's a relatively good consensus for get_or_add, so I suggest changing this PR to use this name.

[akien-mga]

The commit message also needs to be amended.

[YuriSizov]

Thanks!