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

local can_have_space  = characters.can_have_space

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

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,
}
