initial commit

Signed-off-by: Asbjørn Sloth Tønnesen <ast@fiberby.net>

1 files changed, 49 insertions, 0 deletions

diff --git a/lua/inet/set.lua b/lua/inet/set.lua
new file mode 100644
index 0000000..effb0f2
--- /dev/null
+++ b/lua/inet/set.lua
@@ -0,0 +1,49 @@
+local M = {}
+
+local function table_compact(t, n)
+	-- remove nil entries, and reorder
+	local i = 0
+	for j=1,n do
+		if t[j] then
+			if i > 0 then
+				t[i] = t[j]
+				i = i + 1
+			end
+		elseif i == 0 then
+			i = j
+		end
+	end
+	if i > 0 then
+		for j=i,n do
+			t[j] = nil
+		end
+	end
+end
+
+function M.aggregate(t)
+	local flag = true
+	local n = #t
+	for i=1,n do
+		t[i] = t[i]:network()
+	end
+	while flag do -- loop until no aggregatable addresses are found
+		flag = false
+		for i=1,n do
+			local ia = t[i]
+			if ia then
+				local ib = ia:flip() -- counterpart
+				for j=1,n do
+					if j ~= i and t[j] == ib then
+						-- counterpart found, aggregating
+						t[i] = (ia ^ -1):network()
+						t[j] = nil
+						flag = true
+					end
+				end
+			end
+		end
+	end
+	table_compact(t, n)
+end
+
+return M