separated the getrange version which returns the range of the vecto

representaiton rather than the internal representaiton into
`vector_getrange` to make its function explicit

src/threadsafe.jl

@@ -178,6 +178,10 @@ function BangBang.setindex!!(vi::ThreadSafeVarInfo, vals, vns::AbstractVector{<:
     return Accessors.@set vi.varinfo = BangBang.setindex!!(vi.varinfo, vals, vns)
 end
 
+vector_length(vi::ThreadSafeVarInfo) = vector_length(vi.varinfo)
+vector_getrange(vi::ThreadSafeVarInfo) = vector_getrange(vi.varinfo)
+vector_getranges(vi::ThreadSafeVarInfo) = vector_getranges(vi.varinfo)
+
 function set_retained_vns_del_by_spl!(vi::ThreadSafeVarInfo, spl::Sampler)
     return set_retained_vns_del_by_spl!(vi.varinfo, spl)
 end

src/varinfo.jl

@@ -203,6 +203,11 @@ end
 VarInfo(model::Model, args...) = VarInfo(Random.default_rng(), model, args...)
 
 
+"""
+    vector_length(varinfo::VarInfo)
+
+Return the length of the vector representation of `varinfo`.
+"""
 vector_length(varinfo::VarInfo) = length(varinfo.metadata)
 vector_length(varinfo::TypedVarInfo) = sum(length, varinfo.metadata)
 vector_length(md::Metadata) = sum(length, md.ranges)
@@ -615,21 +620,6 @@ getidx(md::Metadata, vn::VarName) = md.idcs[vn]
 Return the index range of `vn` in the metadata of `vi`.
 """
 getrange(vi::VarInfo, vn::VarName) = getrange(getmetadata(vi, vn), vn)
-# For `TypedVarInfo` it's more difficult since we need to keep track of the offset.
-# TOOD: Should we unroll this using `@generated`?
-function getrange(vi::TypedVarInfo, vn::VarName)
-    offset = 0
-    for md in values(vi.metadata)
-        # First, we need to check if `vn` is in `md`.
-        # In this case, we can just return the corresponding range + offset.
-        haskey(md, vn) && return getrange(md, vn) .+ offset
-        # Otherwise, we need to get the cumulative length of the ranges in `md`
-        # and add it to the offset.
-        offset += sum(length, md.ranges)
-    end
-    # If we reach this point, `vn` is not in `vi.metadata`.
-    throw(KeyError(vn))
-end
 getrange(md::Metadata, vn::VarName) = md.ranges[getidx(md, vn)]
 
 """
@@ -648,8 +638,38 @@ Return the indices of `vns` in the metadata of `vi` corresponding to `vn`.
 function getranges(vi::VarInfo, vns::Vector{<:VarName})
     return map(Base.Fix1(getrange, vi), vns)
 end
-# A more efficient version for `TypedVarInfo`.
-function getranges(varinfo::DynamicPPL.TypedVarInfo, vns::Vector{<:DynamicPPL.VarName})
+
+"""
+    vector_getrange(varinfo::VarInfo, varname::VarName)
+
+Return the range corresponding to `varname` in the vector representation of `varinfo`.
+"""
+vector_getrange(vi::VarInfo, vn::VarName) = getrange(getmetadata(vi, vn), vn)
+function vector_getrange(vi::TypedVarInfo, vn::VarName)
+    offset = 0
+    for md in values(vi.metadata)
+        # First, we need to check if `vn` is in `md`.
+        # In this case, we can just return the corresponding range + offset.
+        haskey(md, vn) && return vector_getrange(md, vn) .+ offset
+        # Otherwise, we need to get the cumulative length of the ranges in `md`
+        # and add it to the offset.
+        offset += sum(length, md.ranges)
+    end
+    # If we reach this point, `vn` is not in `vi.metadata`.
+    throw(KeyError(vn))
+end
+vector_getrange(md::Metadata, vn::VarName) = getrange(md, vn)
+
+"""
+    vector_getranges(varinfo::VarInfo, varnames::Vector{<:VarName})
+
+Return the range corresponding to `varname` in the vector representation of `varinfo`.
+"""
+function vector_getranges(varinfo::VarInfo, varname::Vector{<:VarName})
+    return map(Base.Fix1(vector_getrange, varinfo), varname)
+end
+# Specialized version for `TypedVarInfo`.
+function vector_getranges(varinfo::TypedVarInfo, vns::Vector{<:VarName})
     # TODO: Does it help if we _don't_ convert to a vector here?
     metadatas = collect(values(varinfo.metadata))
     # Extract the offsets.
@@ -672,6 +692,7 @@ function getranges(varinfo::DynamicPPL.TypedVarInfo, vns::Vector{<:DynamicPPL.Va
     return ranges
 end
 
+
 """
     getdist(vi::VarInfo, vn::VarName)
 

test/varinfo.jl

@@ -816,7 +816,7 @@ DynamicPPL.getspace(::DynamicPPL.Sampler{MySAlg}) = (:s,)
 
     # NOTE: It is not yet clear if this is something we want from all varinfo types.
     # Hence, we only test the `VarInfo` types here.
-    @testset "getranges for `VarInfo`" begin
+    @testset "vector_getranges for `VarInfo`" begin
 	    @testset "$(model.f)" for model in DynamicPPL.TestUtils.DEMO_MODELS
             vns = DynamicPPL.TestUtils.varnames(model)
             nt = DynamicPPL.TestUtils.rand_prior_true(model)
@@ -829,7 +829,7 @@ DynamicPPL.getspace(::DynamicPPL.Sampler{MySAlg}) = (:s,)
                 # Let's just check all the subsets of `vns`.
                 @testset "$(convert(Vector{Any},vns_subset))" for vns_subset in
                                                                   combinations(vns)
-                    ranges = DynamicPPL.getranges(varinfo, vns_subset)
+                    ranges = DynamicPPL.vector_getranges(varinfo, vns_subset)
                     @test length(ranges) == length(vns_subset)
                     for (r, vn) in zip(ranges, vns_subset)
                         @test x[r] == DynamicPPL.tovec(varinfo[vn])