if not modules then modules = { } end modules ['page-ins'] = {
    version   = 1.001,
    comment   = "companion to page-mix.mkiv",
    author    = "Hans Hagen, PRAGMA-ADE, Hasselt NL",
    copyright = "PRAGMA ADE / ConTeXt Development Team",
    license   = "see context related readme files",
 -- public    = {
 --     functions = {
 --         "inserts.define",
 --         "inserts.getdata",
 --     },
 --     commands = {
 --         "defineinsertion",
 --         "inserttionnumber",
 --     }
 -- }
}

-- Maybe we should only register in lua and forget about the tex end.

structures           = structures or { }
structures.inserts   = structures.inserts or { }
local inserts        = structures.inserts

local report_inserts = logs.reporter("inserts")

local allocate       = utilities.storage.allocate

inserts.stored       = inserts.stored or allocate { } -- combining them in one is inefficient in the
inserts.data         = inserts.data   or allocate { } -- bytecode storage pool

local variables      = interfaces.variables
local v_page         = variables.page
local v_columns      = variables.columns
local v_firstcolumn  = variables.firstcolumn
local v_lastcolumn   = variables.lastcolumn
local v_text         = variables.text

storage.register("structures/inserts/stored", inserts.stored, "structures.inserts.stored")

local data           = inserts.data
local stored         = inserts.stored

for name, specification in next, stored do
    data[specification.number] = specification
    data[name]                 = specification
end

function inserts.define(name,specification)
    specification.name= name
    local number = specification.number or 0
    data[name] = specification
    data[number] = specification
    -- only needed at runtime as this get stored in a bytecode register
    stored[name] = specification
    if not specification.location then
        specification.location = v_page
    end
    return specification
end

function inserts.setup(name,settings)
    local specification = data[name]
    for k, v in next, settings do
        -- maybe trace change
        specification[k] = v
    end
    return specification
end

function inserts.setlocation(name,location) -- a practical fast one
    data[name].location = location
end

function inserts.getlocation(name,location)
    return data[name].location or v_page
end

function inserts.getdata(name) -- or number
    return data[name]
end

function inserts.getname(number)
    return data[name].name
end

function inserts.getnumber(name)
    return data[name].number
end

-- interface

commands.defineinsertion      = inserts.define
commands.setupinsertion       = inserts.setup
commands.setinsertionlocation = inserts.setlocation
commands.insertionnumber      = function(name) context(data[name].number or 0) end

