Add Draw struct

HISTORY.md

@@ -0,0 +1,11 @@
+# 0.1.1
+
+Added the `Draw` struct, which bundles a `VarNamedTuple` of parameter values with a `NamedTuple` of extra information, as well as the accessor functions `parameters` and `extras`.
+This is intended to represent a single MCMC sample.
+
+`Draw` is structurally the same as what used to be called `ParamsWithStats` in DynamicPPL.
+
+# 0.1.0
+
+Initial release.
+This is a direct port of code from AbstractPPL and DynamicPPL, with one major change: `@vn` is now an alias for `@varname`, which is hopefully helpful since it gets used quite a lot.

Project.toml

@@ -1,6 +1,6 @@
 name = "VarNames"
 uuid = "09a315b2-63fc-4165-8d7f-d59368e770cc"
-version = "0.1.0"
+version = "0.1.1"
 authors = ["Penelope Yong <penelopeysm@gmail.com>", "Markus Hauru <markus@mhauru.org>"]
 
 [deps]

docs/src/vnt/api.md

@@ -16,3 +16,9 @@ templated_setindex!!
 densify!!
 skeleton
 ```
+
+```@docs
+Draw
+parameters
+extras
+```

src/VarNames.jl

@@ -70,6 +70,11 @@ export VarNamedTuple,
     SkipTemplate,
     @vnt
 
+include("draw.jl")
+export Draw
+export parameters
+export extras
+
 using BangBang: push!!, empty!!, setindex!!
 export push!!, empty!!, setindex!!
 

src/draw.jl

@@ -0,0 +1,32 @@
+"""
+    Draw{P<:VarNamedTuple,S<:NamedTuple}
+
+A struct that bundles a set of parameter values stored as a `VarNamedTuple`, along with a
+`NamedTuple` of extra information associated with this set of values (for example, this can
+be used to store log-probability values, etc.).
+
+In VarNames.jl, this struct is not used at all; however, it is defined here so that other
+packages can dispatch on it easily.
+"""
+struct Draw{P<:VarNamedTuple,S<:NamedTuple}
+    parameters::P
+    extras::S
+end
+
+"""
+    VarNames.parameters(draw::Draw)::VarNamedTuple
+
+Returns the parameters of the draw as a `VarNamedTuple`.
+"""
+function parameters(draw::Draw)
+    return draw.parameters
+end
+
+"""
+    VarNames.extras(draw::Draw)::NamedTuple
+
+Returns the extra information of the draw as a `NamedTuple`.
+"""
+function extras(draw::Draw)
+    return draw.extras
+end

test/draw.jl

@@ -0,0 +1,16 @@
+module DrawTests
+
+using VarNames
+using Test
+
+@testset "draw" begin
+    # Since it's just a bare struct, just test its API.
+    vnt = VarNamedTuple(x=0.5, y=randn(3))
+    nt = (a=:hello, logjoint=randn())
+    d = Draw(vnt, nt)
+
+    @test parameters(d) == vnt
+    @test extras(d) == nt
+end
+
+end # module DrawTests

test/runtests.jl

@@ -9,4 +9,5 @@ using Test
     include("varname/leaves.jl")
     include("varname/serialize.jl")
     include("varnamedtuple.jl")
+    include("draw.jl")
 end