Shuffle files and functions around for more consistent naming and smaller files

src/diff/print.jl

@@ -0,0 +1,6 @@
+function show(io::IO, diff::Diff)
+   print(io, "Nodes: ")
+   print(io, length(diff.addedNodes) + length(diff.removedNodes))
+   print(io, " Edges: ")
+   print(io, length(diff.addedEdges) + length(diff.removedEdges))
+end

src/diff/properties.jl

@@ -0,0 +1,9 @@
+# return a namedtuple of the lengths of the added/removed nodes/edges
+function length(diff::Diff)
+   return (
+      addedNodes = length(diff.addedNodes), 
+      removedNodes = length(diff.removedNodes), 
+      addedEdges = length(diff.addedEdges), 
+      removedEdges = length(diff.removedEdges)
+   )
+end

src/diff/type.jl

@@ -0,0 +1,13 @@
+const Diff = NamedTuple{
+   (:addedNodes, :removedNodes, :addedEdges, :removedEdges),
+   Tuple{Vector{Node}, Vector{Node}, Vector{Edge}, Vector{Edge}}
+}
+
+function Diff()
+   return (
+      addedNodes = Vector{Node}(), 
+      removedNodes = Vector{Node}(), 
+      addedEdges = Vector{Edge}(), 
+      removedEdges = Vector{Edge}()
+   )::Diff
+end