indexedhashmap.lua

gistfile1.txt

local IndexedHashmap = {
	['new'] = function()
		local self = setmetatable({
			_IndexKey = {},
			_KeyValue = {}
		}, {
			__newindex = function(t, k, v)
				if not table.find(t._IndexKey, k) then
					table.insert(t._IndexKey, k)
				end
				rawset(t._KeyValue, k, v)
			end,
			
			__index = function(t, k)
				return rawget(t._KeyValue, k)
			end,
			
			__len = function(t)
				return #t._KeyValue
			end,
		})
		return self
	end,
	['ipairs'] = function(t)
		local idxkey = t._IndexKey
		local keyval = t._KeyValue
		
		local idx = 1
		
		return function()
			local oldidx = idx
			local oldval = keyval[idxkey[idx]]
			if oldidx and oldval then
				if idx <= #idxkey then
					idx += 1
					return oldidx, oldval
				end
			end
		end
	end,
	['pairs'] = function(t)
		local idxkey = t._IndexKey
		local keyval = t._KeyValue
		
		local idx = 1
		
		return function()
			local oldkey = idxkey[idx]
			local oldval = keyval[oldkey]
			if oldkey and oldval then
				if idx <= #idxkey then
					idx += 1
					return oldkey, oldval
				end
			end
		end
	end,
	['ikpairs'] = function(t)
		local idxkey = t._IndexKey
		local keyval = t._KeyValue
		
		local idx = 1
		
		return function()
			local oldidx = idx
			local oldkey = idxkey[idx]
			local oldval = keyval[oldkey]
			if oldidx and oldkey and oldval then
				if idx <= #idxkey then
					idx += 1
					return oldidx, oldkey, oldval
				end
			end
		end
	end
}


return IndexedHashmap