Update named tuple distribution

Author: devmotion

src/namedtuple/productnamedtuple.jl

@@ -38,31 +38,17 @@ julia> var(d)  # var of marginals
 (x = 1.0, y = [0.031746031746031744, 0.031746031746031744])
 ```
 """
-struct ProductNamedTupleDistribution{Tnames,Tdists,S<:ValueSupport,eltypes} <:
+struct ProductNamedTupleDistribution{Tnames,Tdists,S<:ValueSupport} <:
        Distribution{NamedTupleVariate{Tnames},S}
     dists::NamedTuple{Tnames,Tdists}
 end
 function ProductNamedTupleDistribution(
     dists::NamedTuple{K,V}
 ) where {K,V<:Tuple{Distribution,Vararg{Distribution}}}
     vs = _product_valuesupport(values(dists))
-    eltypes = _product_namedtuple_eltype(values(dists))
-    return ProductNamedTupleDistribution{K,V,vs,eltypes}(dists)
+    return ProductNamedTupleDistribution{K,V,vs}(dists)
 end
 
-_gentype(d::UnivariateDistribution) = eltype(d)
-_gentype(d::Distribution{<:ArrayLikeVariate{S}}) where {S} = Array{eltype(d),S}
-function _gentype(d::Distribution{CholeskyVariate})
-    T = eltype(d)
-    return LinearAlgebra.Cholesky{T,Matrix{T}}
-end
-function _gentype(d::ProductNamedTupleDistribution{K}) where {K}
-    return NamedTuple{K,Tuple{map(_gentype, values(d.dists))...}}
-end
-_gentype(::Distribution) = Any
-
-_product_namedtuple_eltype(dists) = typejoin(map(_gentype, dists)...)
-
 function Base.show(io::IO, d::ProductNamedTupleDistribution)
     return show_multline(io, d, collect(pairs(d.dists)))
 end
@@ -88,8 +74,6 @@ end
 
 # Properties
 
-Base.eltype(::Type{<:ProductNamedTupleDistribution{<:Any,<:Any,<:Any,T}}) where {T} = T
-
 Base.minimum(d::ProductNamedTupleDistribution) = map(minimum, d.dists)
 
 Base.maximum(d::ProductNamedTupleDistribution) = map(maximum, d.dists)
@@ -166,9 +150,9 @@ end
 function Base.rand(
     rng::AbstractRNG, d::ProductNamedTupleDistribution{K}, dims::Dims
 ) where {K}
-    return convert(AbstractArray{<:NamedTuple{K}}, _rand(rng, sampler(d), dims))
+    return rand(rng, sampler(d), dims)
 end
 
-function _rand!(rng::AbstractRNG, d::ProductNamedTupleDistribution, xs::AbstractArray)
-    return _rand!(rng, sampler(d), xs)
+Base.@propagate_inbounds function Base.rand!(rng::AbstractRNG, d::ProductNamedTupleDistribution, xs::AbstractArray)
+    return rand!(rng, sampler(d), xs)
 end

src/samplers/productnamedtuple.jl

@@ -7,13 +7,15 @@ function Base.rand(rng::AbstractRNG, spl::ProductNamedTupleSampler{K}) where {K}
     return NamedTuple{K}(map(Base.Fix1(rand, rng), spl.samplers))
 end
 
-function _rand(rng::AbstractRNG, spl::ProductNamedTupleSampler, dims::Dims)
-    return map(CartesianIndices(dims)) do _
-        return rand(rng, spl)
-    end
+function Base.rand(rng::AbstractRNG, s::ProductNamedTupleSampler, dims::Dims)
+    r = rand(rng, s)
+    out = Array{typeof(r)}(undef, dims)
+    out[1] = r
+    rand!(rng, s, @view(out[2:end]))
+    return out
 end
 
-function _rand!(
+function Base.rand!(
     rng::AbstractRNG, spl::ProductNamedTupleSampler, xs::AbstractArray{<:NamedTuple{K}}
 ) where {K}
     for i in eachindex(xs)

test/namedtuple/productnamedtuple.jl

@@ -68,7 +68,7 @@ using Test
                 (x=product_distribution((x=Normal(), y=Gamma())),),
             ]
                 d = ProductNamedTupleDistribution(nt)
-                @test eltype(d) === eltype(rand(d))
+                @test @test_deprecated(eltype(d)) === eltype(rand(d))
             end
         end
 
@@ -168,7 +168,7 @@ using Test
             d = ProductNamedTupleDistribution(nt)
             rng = MersenneTwister(973)
             x1 = @inferred rand(rng, d)
-            @test eltype(x1) === eltype(d)
+            @test eltype(x1) === @test_deprecated(eltype(d))
             rng = MersenneTwister(973)
             x2 = (
                 x=rand(rng, nt.x), y=rand(rng, nt.y), z=rand(rng, nt.z), w=rand(rng, nt.w)