模組:Pn

--[[
Module that returns one value from a list of unnamed parameters
Named parameter idx is the index of the parameter that is to be returned
Negative indices count backward from the end of the list
==]]

local p = {}

p.getVal = function(frame)
	local args = {}
	-- copy arguments from frame object and its parent
	local has_num_arg = false
	if type(frame.args) == type({}) then
        -- We're being called via #invoke. The args are passed through to the module
        -- from the template page, so use the args that were passed into the template.
		for k, v in pairs(frame.args) do
			has_num_arg = has_num_arg or (not not tonumber(k))
			args[k] = v
		end
		for k, v in pairs(frame:getParent().args) do
			has_num_arg = has_num_arg or (not not tonumber(k))
			args[k] = v
		end
	elseif type(frame) == type({}) then
        -- We're being called from another module or from the debug console, so assume
        -- the args are passed in directly.
		for k, v in pairs(frame) do
			has_num_arg = has_num_arg or (not not tonumber(k))
			args[k] = v
		end
	end
	if not args[1] and not has_num_arg then
		return nil
	end
	local idx = tonumber(args.idx) or 1
	if idx < 0 then 
		local _max = 0
		for k, v in pairs(args) do
			local id = tonumber(k)
			if id and id > _max then _max = id end
		end
		idx = _max + idx + 1 
	end
	return args[idx]
end

return p
Examples
