Reduce number of getproperty and setproperty specializations

Author: goerch

src/DataStructures.jl

@@ -57,9 +57,6 @@ module DataStructures
 
     export findkey
 
-    # _getproperty(x::Nothing, f::Symbol) = @assert false
-    _setproperty!(x::Nothing, f::Symbol, v) = @assert false
-
     include("delegate.jl")
 
     include("deque.jl")

src/avl_tree.jl

@@ -14,22 +14,13 @@ end
 
 AVLTreeNode(d) = AVLTreeNode{Any}(d)
 
-AVLTreeNode_or_null{T} = Union{AVLTreeNode{T}, Nothing}
-
-# _getproperty(x::AVLTreeNode{T}, f::Symbol) where {T} = getfield(x, f)
-# Base.getproperty(x::AVLTreeNode_or_null{T}, f::Symbol) where {T} =
-#     _getproperty(x, f)
-
 _setproperty!(x::AVLTreeNode{T}, f, v) where {T} =
-    # setfield!(x, f, convert(fieldtype(typeof(x), f), v))
     setfield!(x, f, v)
-_setproperty!(x::AVLTreeNode{T}, f, ::Nothing) where {T} =
-    setfield!(x, f, nothing)
-_setproperty!(x::AVLTreeNode{T}, f, v::AVLTreeNode{T}) where {T} =
-    setfield!(x, f, v)
-Base.setproperty!(x::AVLTreeNode_or_null{T}, f::Symbol, v) where {T} =
+Base.setproperty!(x::AVLTreeNode{T}, f::Symbol, v) where {T} =
     _setproperty!(x, f, v)
 
+AVLTreeNode_or_null{T} = Union{AVLTreeNode{T}, Nothing}
+
 mutable struct AVLTree{T}
     root::AVLTreeNode_or_null{T}
     count::Int

src/red_black_tree.jl

@@ -17,18 +17,9 @@ end
 RBTreeNode() = RBTreeNode{Any}()
 RBTreeNode(d) = RBTreeNode{Any}(d)
 
-# _getproperty(x::RBTreeNode{K}, f) where {K} = getfield(x, f)
-# Base.getproperty(x::Union{Nothing, RBTreeNode{K}}, f::Symbol) where {K} =
-#     _getproperty(x, f)
-
 _setproperty!(x::RBTreeNode{K}, f, v) where {K} =
-    # setfield!(x, f, convert(fieldtype(typeof(x), f), v))
-    setfield!(x, f, v)
-_setproperty!(x::RBTreeNode{K}, f, ::Nothing) where {K} =
-    setfield!(x, f, nothing)
-_setproperty!(x::RBTreeNode{K}, f, v::RBTreeNode{K}) where {K} =
     setfield!(x, f, v)
-Base.setproperty!(x::Union{Nothing, RBTreeNode{K}}, f::Symbol, v) where {K} =
+Base.setproperty!(x::RBTreeNode{K}, f::Symbol, v) where {K} =
     _setproperty!(x, f, v)
 
 function create_null_node(K::Type)