This module provides an easy and efficient way to generate lengthy strings.

First, load the module.

local newBuffer = require('Module:OutputBuffer')

Then, create the buffer and the functions that act on it.

local getBuffer, print, printf = newBuffer()
local text = getBuffer(sep)

Returns the contents of the buffer, with an optional separator string sep.

print(s)

Adds the string s to the buffer.

printf(s, ...)

Adds the string s to the buffer. The string is formatted with any subsequent arguments, following the rules used for string.format.

local newBuffer = require('Module:OutputBuffer')
local p = {}

function p.main()
	local getBuffer, print, printf = newBuffer()
	print('Welcome to the English Wikipedia.')
	printf('There are currently %d articles on this site.', mw.site.stats.articles)
	return getBuffer(' ')
end

return p

-- Assuming this module's name is "TestModule", and that mw.site.stats.articles returns 4500000,
-- {{#invoke:TestModule|main}} would output:
-- "Welcome to the English Wikipedia. There are currently 4500000 articles on this site."

return function()
	local buffer = {}
	return function(sep)
		local b = buffer
		buffer = {}
		return table.concat(b, sep)
	end,
	function(text)
		buffer[#buffer + 1] = text
	end,
	function(...)
		buffer[#buffer + 1] = string.format(...)
	end
end