Remove GlobalMetadata

This originated from feedback from others a while back but isn't
terribly useful, and now that we can set variables in modules it's
nearly completely useless.

README.md

@@ -77,39 +77,6 @@ julia> mr.den
 Here we attached the same metadata to a rational number.
 Again, our metadata is now considered the properties of `mr`, but we can still access the parent's properties.
 
-If the type you want to attach metadata to is mutable then each instance has a unique global identifier and you may attach metadata to a global dictionary.
-```julia
-julia> x = ones(2, 2);
-
-julia> @attach_metadata(x, meta);
-
-julia> @metadata!(x, :z, 3);
-
-julia> @metadata(x, :z)
-3
-
-julia> Pair(:x, 1) in @metadata(x)
-true
-```
-
-If users want to access all of the metadata from one structure and attach it to another they should instead use `share_metadata(src, dst)` or `copy_metadata(src, dst)`.
-```julia
-julia> mx = attach_metadata(ones(2, 2), @metadata(x));
-
-julia> mx2 = share_metadata(mx, ones(2, 2));
-
-julia> metadata(mx2) === metadata(mx)
-true
-
-julia> mx3 = copy_metadata(mx2, ones(2, 2));
-
-julia> metadata(mx3) === metadata(mx2)
-false
-
-julia> metadata(mx3) == metadata(mx2)
-true
-```
-
 # Creating New Metadata Types
 
 This package creates a very minimal number of dedicated structures and creating new dedicated structures that use this interface is encouraged.

src/Metadata.jl

@@ -13,12 +13,6 @@ using Statistics
 using Test
 
 export
-    @attach_metadata,
-    @metadata,
-    @metadata!,
-    @has_metadata,
-    @copy_metadata,
-    @share_metadata,
     attach_metadata,
     copy_metadata,
     getmeta,
@@ -29,7 +23,6 @@ export
 
 include("MetaStruct.jl")
 include("interface.jl")
-include("GlobalMetadata.jl")
 include("MetaDict.jl")
 include("MetaTuple.jl")
 include("MetaIO.jl")

test/runtests.jl

@@ -6,30 +6,16 @@ using Metadata
 using Test
 
 using ArrayInterface: parent_type, StaticInt
-using Metadata: MetaArray, no_data, GlobalMetadata
-
+using Metadata: MetaArray, no_data
 
 Aqua.test_all(Metadata)
 
 @test isempty(detect_ambiguities(Metadata, Base))
 
-@testset "methods" begin
+@testset "interface" begin
     io = IOBuffer()
     show(io, Metadata.no_data)
     @test String(take!(io)) == "no_data"
-    @test Metadata.MetadataPropagation(Metadata.NoData) == Metadata.DropMetadata()
-    @test @inferred(metadata(Main)) isa GlobalMetadata
-    x = rand(4)
-    m = metadata(Main)
-    @test isempty(m)
-    get!(m, objectid(x), Dict{Symbol,Any}())
-    @test !isempty(m)
-    @test first(keys(m)) == objectid(x)
-    @test m[objectid(x)] == Dict{Symbol,Any}()
-    @test length(m) == 1
-    p, state = iterate(m)
-    @test p == (objectid(x) => Dict{Symbol,Any}())
-    @test iterate(m, state) === nothing
 end
 
 #=
@@ -105,36 +91,6 @@ end
     include("MetaIO.jl")
 end
 
-@testset "GlobalMetadata" begin
-    x = ones(2, 2)
-    meta = (x = 1, y = 2)
-    @attach_metadata(x, meta)
-    @test @metadata(x, :x) == 1
-    @test @metadata(x, :y) == 2
-
-    struct MyType{X}
-        x::X
-    end
-
-    x = MyType(ones(2,2))
-    GC.gc()
-    @test @metadata(x) == Metadata.no_data  # test finalizer
-
-    @test metadata_type(Main) <: Metadata.GlobalMetadata
-    @attach_metadata(x, meta)
-    @test @metadata(x, :x) == 1
-    @test @metadata(x, :y) == 2
-    x = MyType(1)
-    GC.gc()
-    @test @metadata(x) == Metadata.no_data  # test finalizer on nested mutables
-    @test_logs(
-        (:warn, "Cannot create finalizer for MyType{$Int}. Global dictionary must be manually deleted."),
-        @attach_metadata(x, meta)
-    )
-    @test @metadata(x, :x) == 1
-    @test @metadata(x, :y) == 2
-end
-
 m = (x = 1, y = 2, suppress= [:x])
 io = IOBuffer()
 Metadata.metadata_summary(io, m)