wea.parse.chance: add weight mode

worldeditadditions/utils/parse/chance.lua

@@ -1,12 +1,15 @@
 
 --- Parses a chance value, and returns the 1-in-N value thereof.
--- @param	str	string	The string to parse.
+-- @param	str				string	The string to parse.
+-- @param	invert_percent	string	The operation mode. Valid modes: "1-in-n" (default), "weight". "1-in-n" refers to a 1-in-N chance of something happening (lower numbers mean greater likelihood). "weight", on the other hand, is instead a weighting that something will happen (higher numbers mean a greater likelihood).
 -- @returns	number|nil	The 1-in-N chance if parsing was successful, otherwise nil.
-function worldeditadditions.parse.chance(str)
+function worldeditadditions.parse.chance(str, mode)
+	if not mode then mode = "1-in-n" end
 	if tonumber(str) ~= nil then return tonumber(str) end
 	if str:sub(#str) == "%" then
 		local result = tonumber(str:sub(1, #str-1))
 		if not result then return nil end
+		if mode == "weight" then result = 100 - result end
 		return 1 / (result / 100) -- Convert percentage to 1-in-N chance
 	end
 	return nil

worldeditadditions/utils/parse/weighted_nodes.lua

@@ -27,7 +27,7 @@ function worldeditadditions.parse.weighted_nodes(parts, as_list, func_normalise)
 			mode = MODE_EITHER
 		elseif mode == MODE_EITHER then
 			-- print("mode: either");
-			local chance = tonumber(part)
+			local chance = worldeditadditions.parse.chance(part, "weight")
 			if not chance then
 				-- print("not a chance, trying a node name")
 				local node_name
@@ -59,5 +59,7 @@ function worldeditadditions.parse.weighted_nodes(parts, as_list, func_normalise)
 		else result[last_node_name] = 1 end
 	end
 	
+	print(worldeditadditions.format.map(result, " "))
+	
 	return true, result
 end