$define SPE = "\u{fffe}"  -- unused unicode character in Specials block
$define SPF = "\u{ffff}"  -- ditto

local function tokenize(str, sep, esc)
    str = str:replace(esc .. esc, SPE):replace(esc .. sep, SPF)
    str = (str[-1] == esc) ? (str:sub(1, -2):replace(esc, "") .. esc) : (str:replace(esc, ""))
    return str:split(sep):map(|s| -> s:replace(SPE, esc):replace(SPF, sep))
end

local str = "one^|uno||three^^^^|four^^^|^cuatro|"
local sep = "|"
local esc = "^"
local items = tokenize(str, sep, esc)
for items as item do print((item == "") ? "(empty)" : item) end