Re: [xml-dev] The illusion of simplicity and low cost in data designand

[Rick Jelliffe <rjelliffe@allette.com.au>]

If files were layered the way that networks are layered, the data for each level would commence with the information needed to announce what was immediately contained within. There would be no resorting to mythical outside systems that somehow know things about the document. 

Each layer need 1) a convention to say what it is by its metadata, and 2) a series of conventions for how to look in its data to find enough information about the next layer to be able to read its metadata.

XML provided the first (headers, doctyoe, namespaces, etc) but kinda fails to provide the second (standard inline conventions to introduce embedded notations). Which is why it struggles whenever it has to contain non-xml data inside: hence see ludicrous approaches like requiring an external schema  to say some element value is bin64.  

Regards 

Rick

On Sun, 14 Aug 2022, 8:56 pm Michael Kay, <mike@saxonica.com> wrote:

>So perhaps the idea that the best place for the metadata of a file is IN the file (e.g.  as magic number, as XML header, etc) not WITH the file, is not hacky but the most unified and best approach? 

If it was layered the way protocols are layered, then there would be one layer at which the metadata is visible as part of the file content, and another layer at which you only see the content.

Michael Kay
Saxonica