Module:Highest archive number
Documentation for this module may be created at Module:Highest archive number/doc
-- This module finds the highest existing archive number for a set of talk
-- archive pages.
local expSearch = require('Module:Exponential search')
local p = {}
local function raiseStartNumberError(start)
error(string.format(
'Invalid start number "%s" supplied to [[Module:Highest archive number]] (must be an integer)',
tostring(start)
), 3)
end
local function pageExists(page)
local success, exists = pcall(function()
return mw.title.new(page).exists
end)
return success and exists
end
function p._main(prefix, start)
-- Check our inputs
if type(prefix) ~= 'string' or not prefix:find('%S') then
error('No prefix supplied to [[Module:Highest archive number]]', 2)
end
if start ~= nil and (type(start) ~= "number" or math.floor(start) ~= start) then
raiseStartNumberError(start)
end
start = start or 1
-- Do an exponential search for the highest archive number
local result = expSearch(function (i)
local archiveNumber = i + start - 1
local page = prefix .. tostring(archiveNumber)
return pageExists(page)
end, 10)
if result == nil then
-- We didn't find any archives for our prefix + start number
return nil
else
-- We found the highest archive, but the number is always 1-based, so
-- adjust it for our start number
return result + start - 1
end
end
function p.main(frame)
local args = require('Module:Arguments').getArgs(frame, {
trim = false,
removeBlanks = false,
wrappers = 'Template:Highest archive number'
})
local prefix = args[1]
-- Get the start archive number, if specified.
local start = args.start
if start == "" then
start = nil
elseif start then
start = tonumber(start)
if not start then
raiseStartNumberError(args.start)
end
end
return p._main(prefix, start)
end
return p