Module:Yesno

local p = {}
 
function p.yesno( frame )
 
    local retvals = {
        yes   = "yes",
        no    = "",
        ["¬"] = ""
    }
 
    local any = false
    for k,v in pairs( frame.args ) do
        any = true
        retvals[k] = v
    end
 
    val = frame.args[1]
 
    if (val == nil and not any) or val == '¬' then
        return retvals['¬']
    end
 
    val = (val or ''):lower()
    val = val:match'^%s*(.*%S)' or ''
 
    if val == '' then
        return retvals['blank'] ~= nil and retvals['blank'] or retvals['no']
    elseif val == 'n' or val == 'no'  or val == '0' then
        return retvals['no']
    elseif val == 'y' or val == 'yes' or val == '1' or retvals['def'] == nil then
        return retvals['yes']
    else
        return retvals['def']
    end
end
 
return p