From bb392ca2cebf0e5c85cb10f824a1e4d8d54131ab Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Asbj=C3=B8rn=20Sloth=20T=C3=B8nnesen?= <ast@fiberby.net>
Date: Mon, 6 Mar 2017 11:00:14 +0000
Subject: set: basic support for looping over sets
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Signed-off-by: Asbjørn Sloth Tønnesen <ast@fiberby.net>
---
 lua/inet/set.lua | 56 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 56 insertions(+)

diff --git a/lua/inet/set.lua b/lua/inet/set.lua
index 27c9388..5999f65 100644
--- a/lua/inet/set.lua
+++ b/lua/inet/set.lua
@@ -52,4 +52,60 @@ function M.aggregate(t)
 	table_compact(t, n)
 end
 
+local function has(set, addr)
+	assert(set)
+	for i=1,#set do
+		local elem = set[i]
+		if elem >= addr then
+			local exclude = set.exclude
+			if exclude then
+				return not has(exclude, addr)
+			else
+				return true
+			end
+		end
+	end
+	return false
+end
+
+function M.iterator(set)
+	local excl = set.exclude
+	local i = 1
+	if #set < 1 then return nil, 'empty set' end
+	local addr = set[i]
+	local net = set[i]:network()
+	local function iter()
+		if not addr then return end
+		local ret
+		ret = addr/32
+		addr = addr + 1
+		if addr:network() ~= net then
+			i = i + 1
+			addr = set[i]
+			if addr then
+				net = set[i]:network()
+			end
+		end
+		if has(excl, ret) then
+			return iter()
+		end
+		return ret
+	end
+
+	return iter
+end
+
+function M.loopiterator(set)
+	local orig_iter = M.iterator(set)
+	local function iter()
+		local addr = orig_iter()
+		if not addr then
+			orig_iter = M.iterator(set)
+			addr = orig_iter()
+		end
+		return addr
+	end
+	return iter
+end
+
 return M
-- 
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