Make `ScopedValues.get` a method of `Base.get`

[LilithHafner]

ScopedValues.get(::ScopedValues.ScopedValue) performs a very similar role as Base.get(collection, index, default) and I think they should have the same API and name, i.e. rename ScopedValues.get to Base.get and make its API conform to the Base get API.

Right now, ScopedValues.get is it's own generic function, distinct from Base.getindex and from Base.get.

ScopedValues was introduced in 1.11, so this needs to be done before the 1.11 release if we want to do it at all.

Reading #50958, I don't see any explicit discussion about this name, but perhaps I'm missing something.

cc @vchuravy

[vchuravy]

I am confused? get and getindex both exist?

[LilithHafner]

Ah, silly me, getindex(::ScopedValue) is already defined, yes. Did we consider making ScopedValues.get be a method of Base.get and follow the Base.get API, though without the key argument?

[DilumAluthge]

Maybe this line:

julia/base/scopedvalues.jl

Line 149 in baca8ba

function get(val::ScopedValue{T}) where {T}

Should be changed to this instead?

- function get(val::ScopedValue{T}) where {T}
+ function Base.get(val::ScopedValue{T}) where {T}

[DilumAluthge]

Ah Lilith beat me to it.

[vchuravy]

ScopedValues.get doesn't match the semantics of get so I intentionally didn't use Base.get

[LilithHafner]

We can do this after 1.11 in a nonbreaking way.

---

From triage: it's complicated, let's talk about it later.

---

In the future we could define this and merge the functions

mutable struct Secret end
const SECRET = Secret()
function Base.get(x, index) 
	res = get(x, index, SECRET)
    res === SECRET ? nothing : Some(res)
end

[KristofferC]

Base.get takes three arguments so it's unclear what the meaning of that two arg get is.

[JeffBezanson]

I think if Base.get had 1- or 2-argument methods they would work like this, and also if ScopedValue.get had a 3-argument method it would work like Base.get, so they seem compatible to me.