Module:Detect singular

Module documentation[create] [purge]

You might want to create a documentation page for this Scribunto module.
Editors can experiment in this module's sandbox (create | mirror) and testcases (create) pages.
Add categories to the /doc subpage. Subpages of this module.

local p = {}
local getArgs = require('Module:Arguments').getArgs
local yesNo = require('Module:Yesno')

local function plainFind(s, sub)
	return mw.ustring.find(s, sub, 1, true)
end

local function countMatches(s, pattern)
	local _, count = mw.ustring.gsub(s, pattern, '')
	return count
end

function p._main(args)
	local checkComma = not yesNo(args.no_comma,true)
	local checkBullets = yesNo(args.bullets,true)
	local s = args[1]  -- the input string
	if not s then
		return nil -- empty input returns nil
	end
	s = tostring(s)
	if plainFind(s,'forcedetectsingular') then -- magic data string to return true
		return true
	end
	if plainFind(s,'forcedetectplural') then -- magic data string to return false
		return false
	end
	-- count number of list items
	local numListItems = countMatches(s,'<%s*li')
	-- if exactly one, then singular, if more than one, then plural
	if numListItems == 1 then
		return true
	end
	if numListItems > 1 then
		return false
	end
	-- replace all wikilinks with fixed string
	s = mw.ustring.gsub(s,'%b[]','WIKILINK') 
	local hasComma = checkComma and mw.ustring.find(s, '[%a%s],[%a%s]') 
	local hasAnd = mw.ustring.find(s,'[,%s]and%s')
	local hasBreak = mw.ustring.find(s,'<%s*br')
	local hasBullets = checkBullets and countMatches(s,'%*+') > 1
	local multipleQids = mw.ustring.find(s,'Q%d+[%p%s]+Q%d+') -- has multiple QIDs in a row
	return not (hasComma or hasAnd or hasBreak or hasBullets or multipleQids)
end

function p.main(frame)
	local args = getArgs(frame)
	if p._main(args) then
		return 1
	end
	return ""
end

return p