local vars = {}

function string.split(str, sep)
    sep = sep or '%s'

    local parts = pandoc.List()

    for field, s in str:gmatch("([^" .. sep .. "]*)(" .. sep .. "?)") do
        parts:insert(field)
        if s == "" then return parts end
    end
end

function meta(meta) vars = meta end

function str(el)
    local prefix, varref, suffix = el.text:match('^(.*)%%(.*)%%(.*)$')

    if varref then
        local parts = varref:split(".")
        local var = vars

        for i = 1, #parts do
            local part = parts[i]
            local v = var[part]

            if not v then return el end

            var = v
        end

        if var then return pandoc.Str(prefix .. var .. suffix) end
    end

    return el
end

return { { Meta = meta }, { Str = str } }