Backport 3-arg rand to AbstractPPL 0.5.x (#80)

* Back-port 3-arg `rand` interface.

* Bump version for interface change.

* Update CI.yml

* Fix test errors.

---------

Co-authored-by: Hong Ge <[email protected]>

.github/workflows/CI.yml

@@ -9,6 +9,10 @@ on:
       - trying
       # Build the main branch.
       - main
+  pull_request:
+    branches:
+      - main
+      - releases-0.5.x
 
 jobs:
   test:

Project.toml

@@ -3,7 +3,7 @@ uuid = "7a57a42e-76ec-4ea3-a279-07e840d6d9cf"
 keywords = ["probablistic programming"]
 license = "MIT"
 desc = "Common interfaces for probabilistic programming"
-version = "0.5.3"
+version = "0.5.4"
 
 [deps]
 AbstractMCMC = "80f14c24-f653-4e6a-9b94-39d6b0f70001"

src/abstractprobprog.jl

@@ -1,5 +1,6 @@
 using AbstractMCMC
 using DensityInterface
+using Random
 
 
 """
@@ -60,3 +61,22 @@ m = decondition(condition(m, obs))
 should hold for generative models `m` and arbitrary `obs`.
 """
 function condition end
+
+
+"""
+    rand([rng=Random.default_rng()], [T=NamedTuple], model::AbstractProbabilisticProgram) -> T
+
+Draw a sample from the joint distribution of the model specified by the probabilistic program.
+
+The sample will be returned as format specified by `T`.
+"""
+Base.rand(rng::Random.AbstractRNG, ::Type, model::AbstractProbabilisticProgram)
+function Base.rand(rng::Random.AbstractRNG, model::AbstractProbabilisticProgram)
+    return rand(rng, NamedTuple, model)
+end
+function Base.rand(::Type{T}, model::AbstractProbabilisticProgram) where {T}
+    return rand(Random.default_rng(), T, model)
+end
+function Base.rand(model::AbstractProbabilisticProgram)
+    return rand(Random.default_rng(), NamedTuple, model)
+end

src/graphinfo.jl

@@ -444,9 +444,9 @@ function Random.rand!(m::AbstractPPL.GraphPPL.Model{T}) where T
 end
 
 """
-    rand!(rng::AbstractRNG, m::Model)
+    rand(m::Model)
 
-Draw random samples from the model and mutate the node values. 
+Draw random samples from the model and return the samples as NamedTuple. 
 
 # Examples
 
@@ -470,11 +470,15 @@ julia> rand(m)
 (μ = 1.0, s2 = 1.0907695400401212, y = 0.05821954440386368)
 ```
 """
-function Random.rand(rng::AbstractRNG, sm::Random.SamplerTrivial{Model{Tnames, Tinput, Tvalue, Teval, Tkind}}) where {Tnames, Tinput, Tvalue, Teval, Tkind}
+function Base.rand(rng::AbstractRNG, sm::Random.SamplerTrivial{Model{Tnames, Tinput, Tvalue, Teval, Tkind}}) where {Tnames, Tinput, Tvalue, Teval, Tkind}
     m = deepcopy(sm[])
     get_model_values(rand!(rng, m))
 end
 
+function Base.rand(rng::AbstractRNG, ::Type{NamedTuple}, m::Model)
+    rand(rng, Random.SamplerTrivial(m))
+end
+
 """
     logdensityof(m::Model)
 

src/varname.jl

@@ -460,8 +460,10 @@ resolved as `VarName` only supports non-dynamic indexing as determined by
 ```jldoctest
 julia> # Dynamic indexing is not allowed in `VarName`
        @varname(x[end])
-ERROR: UndefVarError: x not defined
-[...]
+ERROR: UndefVarError: `x` not defined
+Stacktrace:
+ [1] top-level scope
+   @ none:1
 
 julia> # To be able to resolve `end` we need `x` to be available.
        x = randn(2); @varname(x[end])

test/abstractprobprog.jl

@@ -0,0 +1,37 @@
+using AbstractPPL
+using Random
+using Test
+
+mutable struct RandModel <: AbstractProbabilisticProgram
+    rng
+    T
+end
+
+function Base.rand(rng::Random.AbstractRNG, ::Type{T}, model::RandModel) where {T}
+    model.rng = rng
+    model.T = T
+    return nothing
+end
+
+@testset "AbstractProbabilisticProgram" begin
+    @testset "rand defaults" begin
+        model = RandModel(nothing, nothing)
+        rand(model)
+        @test model.rng == Random.default_rng()
+        @test model.T === NamedTuple
+        rngs = [Random.default_rng(), Random.MersenneTwister(42)]
+        Ts = [NamedTuple, Dict]
+        @testset for T in Ts
+            model = RandModel(nothing, nothing)
+            rand(T, model)
+            @test model.rng == Random.default_rng()
+            @test model.T === T
+        end
+        @testset for rng in rngs
+            model = RandModel(nothing, nothing)
+            rand(rng, model)
+            @test model.rng === rng
+            @test model.T === NamedTuple
+        end
+    end
+end

test/runtests.jl

@@ -12,6 +12,7 @@ using Test
 
 @testset "AbstractPPL.jl" begin
     include("deprecations.jl")
+    include("abstractprobprog.jl")
     include("graphinfo/graphinfo.jl")
     @testset "doctests" begin
         DocMeta.setdocmeta!(
@@ -20,6 +21,6 @@ using Test
             :(using AbstractPPL);
             recursive=true,
         )
-        doctest(AbstractPPL; manual=false)
+        doctest(AbstractPPL; manual=false, fix=true)
     end
 end