Module:Iteration/doc

This module contains the functions for different templates, solving their iteration problem

The wikipedia template coding does not support the repetitive processing of a parameter set,

which leads often to a very primitive and long chain of parameter checks in the kind of

{{#if:{{{1|}}} | perform an action with parameter 1 }}
{{#if:{{{2|}}} | perform an action with parameter 2 }}
{{#if:{{{3|}}} | perform an action with parameter 3 }}
{{#if:{{{4|}}} | perform an action with parameter 4 }}
•••
•••
{{#if:{{{33|}}} perform an action with parameter 33 }}

with the disadvantage that such a construct will fail as soon as there comes a 34^nd parm.

I always thought that with Lua and its for loops this iterations should be possible, somehow.
After long searching without any success and without an idea how to perform it, I asked at several forums

and got finally from User:Trappist the monk the helping hint to solve it with a control structure like

	local out = {}
	for i, v in ipairs (args) do
		table.insert (out, frame:expandTemplate{ title = title, args = v })
	end
	return table.concat (out)

The functions contained therein are from very simple, just one parameter to pass,
to more complicated ones, where e.g. a pair of parameters needs kind of a flip-flop switch
when always a tupel of e.g. an item and its correlated text needs to be passed.

When there are tuples, tripels etc., the table.insert occurs, when the last element is processed;
this performs problems when the last group is incomplete – it should be finished with empty values
to trigger the table.insert. The check with table.maxn seems not to work correctly ?
This problem is solved differently, for the function "attribs" with a primitive workaround.