Difference between revisions of "Module:TableTools"

Module:TableTools (view source)

297 bytes removed , 15:11, 19 December 2013

fix the valueUnion function for NaNs (and make it a lot simpler to boot)

Anonymous user

@@ Line 17: / Line 17: @@
 local infinity = math.huge
 local checkType = libraryUtil.checkType
--- Define a unique value to represent NaN. This is because NaN cannot be used as a table key.
-local nan = {}
 --[[
@@ Line 140: / Line 137: @@
 function p.valueUnion(...)
 	local lim = select('#', ...)
-	if lim == 0 then
+	if lim < 2 then
-		error("no arguments passed to 'valueUnion'", 2)
+		error(lim .. ' argument' .. (lim == 1 and '' or 's') .. " passed to 'valueUnion' (minimum is 2)", 2)
 	end
-	local vals, ret = {}, {}
+	local isNan = p.isNan
+	local ret, exists = {}, {}
 	for i = 1, lim do
 		local t = select(i, ...)
 		checkType('valueUnion', i, t, 'table')
 		for k, v in pairs(t) do
-			if type(v) == 'number' and tostring(v) == '-nan' then
+			if isNan(v) then
-				v = nan -- NaN cannot be a table key, so use a proxy variable.
+				ret[#ret + 1] = v
+			elseif not exists[v] then
+				ret[#ret + 1] = v
+				exists[v] = true
 			end
-			vals[v] = true
-		end
-	end
-	for val in pairs(vals) do
-		if val == nan then
-			-- This ensures that we output a NaN when we had one as input, although
-			-- they may have been generated in a completely different way.
-			val = 0/0
 		end
-		ret[#ret + 1] = val
 	end
 	return ret