Fix for subsumes method ambiguity (#71)

What the title says.

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

Author: torfjelde

Project.toml

@@ -3,7 +3,7 @@ uuid = "7a57a42e-76ec-4ea3-a279-07e840d6d9cf"
 keywords = ["probablistic programming"]
 license = "MIT"
 desc = "Common interfaces for probabilistic programming"
-version = "0.5.2"
+version = "0.5.3"
 
 [deps]
 AbstractMCMC = "80f14c24-f653-4e6a-9b94-39d6b0f70001"

src/varname.jl

@@ -274,6 +274,7 @@ end
 # `PropertyLens{:a}` and `PropertyLens{:b}` we immediately know that they do not subsume
 # each other since at the same level/depth they access different properties.
 # E.g. `x`, `x[1]`, i.e. `u` is always subsumed by `t`
+subsumes(::IdentityLens, ::IdentityLens) = true  # disambiguation
 subsumes(t::IdentityLens, u::Lens) = true
 subsumes(t::Lens, u::IdentityLens) = false