if not modules then modules = { } end modules ['spac-hor'] = {
    version   = 1.001,
    comment   = "companion to spac-hor.mkiv",
    author    = "Hans Hagen, PRAGMA-ADE, Hasselt NL",
    copyright = "PRAGMA ADE / ConTeXt Development Team",
    license   = "see context related readme files"
}

local chardata  = characters.data
local peekchar  = tokens.scanners.peekchar
local ctx_space = context.space

local can_have_space = table.tohash {
    "lu", "ll", "lt", "lm", "lo", -- letters
 -- "mn", "mc", "me",             -- marks
    "nd", "nl", "no",             -- numbers
    "ps", "pi",                   -- initial
 -- "pe", "pf",                   -- final
 -- "pc", "pd", "po",             -- punctuation
    "sm", "sc", "sk", "so",       -- symbols
 -- "zs", "zl", "zp",             -- separators
 -- "cc", "cf", "cs", "co", "cn", -- others
}

interfaces.implement {
    name      = "autoinsertnextspace",
    protected = true,
    public    = true,
    actions   = function()
        local char = peekchar()
        if char then
            local d = chardata[char]
            if d and can_have_space[d.category] then
                ctx_space()
            end
        end
    end,
}

local nuts = nodes.nuts
local tonut = nodes.tonut
local traverseglue = nuts.traversers.glue
local setwidth = nodes.nuts.setwidth
local indentskip_code = nodes.gluecodes.indentskip
local texgetnest = tex.getnest

local function lateindent(amount)
    local head = tonut(texgetnest("top","head"))
    if head then
        for n, s in traverseglue, head do
            if s == indentskip_code then
                setwidth(n,amount or 0)
            end
        end
    end
end

interfaces.implement {
    name      = "lateindent",
    public    = true,
    protected = "true",
    arguments = "dimension",
    actions   = lateindent,
}
interfaces.implement {
    name      = "lateundent",
    public    = true,
    protected = "true",
    actions   = lateindent,
}