Dict interface for varinfo is weird

[penelopeysm]

julia> using DynamicPPL, Distributions

julia> @model function f()
           x ~ Normal()
           y ~ Normal()
           z = Vector{Float64}(undef, 2)
           z .~ Normal()
       end
f (generic function with 2 methods)

julia> v = VarInfo(f());

julia> keys(v)
4-element Vector{VarName}:
 x
 y
 z[1]
 z[2]

julia> values(v) isa VarInfo
true

julia> collect(pairs(v))
ERROR: MethodError: no method matching length(::VarInfo{@NamedTuple{…}, DynamicPPL.AccumulatorTuple{…}})
The function `length` exists, but no method is defined for this combination of argument types.

keys(v) makes sense, but I would expect values(v) to give the corresponding values not just return the VarInfo, and pairs(v) to give the (key, value) pairs (instead I don't even know what it returns because I can't get it into a vector).

This means that you have to do odd things like this, when it should probably just be Dict(pairs(v)).

julia> Dict(k => v[k] for k in keys(v))
Dict{VarName, Float64} with 4 entries:
  y    => -1.03936
  x    => -0.114171
  z[2] => 0.417849
  z[1] => -0.997633