Merge pull request #86 from TuringLang/logp

Make `logp` concretely typed by default and respect types in `resetlogp!`

Author: mohamed82008

src/varinfo.jl

@@ -485,7 +485,7 @@ end
 
 # VarInfo
 
-VarInfo(meta=Metadata()) = VarInfo(meta, Ref{Real}(0.0), Ref(0))
+VarInfo(meta=Metadata()) = VarInfo(meta, Ref{Float64}(0.0), Ref(0))
 
 """
     TypedVarInfo(vi::UntypedVarInfo)
@@ -618,8 +618,7 @@ acclogp!(vi::AbstractVarInfo, logp::Real) = vi.logp[] += logp
 Reset the value of the log of the joint probability of the observed data and parameters
 sampled in `vi` to 0.
 """
-resetlogp!(vi::AbstractVarInfo) = setlogp!(vi, 0)
-
+resetlogp!(vi::AbstractVarInfo) = setlogp!(vi, zero(getlogp(vi)))
 
 """
     get_num_produce(vi::VarInfo)

test/varinfo.jl

@@ -391,13 +391,13 @@ include(dir*"/test/test_utils/AllUtils.jl")
     @testset "varinfo" begin
         dists = [Normal(0, 1), MvNormal([0; 0], [1.0 0; 0 1.0]), Wishart(7, [1 0.5; 0.5 1])]
         function test_varinfo!(vi)
-            @test getlogp(vi) == 0
+            @test getlogp(vi) === 0.0
             setlogp!(vi, 1)
-            @test getlogp(vi) == 1
+            @test getlogp(vi) === 1.0
             acclogp!(vi, 1)
-            @test getlogp(vi) == 2
+            @test getlogp(vi) === 2.0
             resetlogp!(vi)
-            @test getlogp(vi) == 0
+            @test getlogp(vi) === 0.0
 
             spl2 = Sampler(PG(5, :w, :u), empty_model())
             vn_w = @varname w