The 'Subject' Datatype

This document describes the XML datatype, i.e. lexical-to-value mapping, identified by the URI "http://ns.nuke24.net/Datatypes/Subject".

Lexical scope: Any string or byte sequence in one of the formats listed below.

Value scope: Anything that can be described by those formats.

This datatype is implied by the "x-rdf-subject:" URI prefix, or "#" + (optional fragment ID) URI suffixes.

In some contexts (such when implied by URI with a fragment part, or when using TOGVM's DataInterpretation/InterpretData expression/function), a fragment identifier can be provided.

Primarily intended to support:

RDF+XML
Value is the object described by the root element, or element with rdf:ID if a fragment is given.
TOGoS Binary Blocks (header: "TBB" + (char)0x81)
Value is the subject of TBB document.
TOGoS Text Blocks (header: "#TTB " + datatype URI)
Value is the subject of TTB document. (see https://www.nuke24.net/docs/2012/TOGoSBinaryBlocks.html#TTB)
JSON-LD files
Value is the object described by the root JSON-LD object, or, if a fragment is indicated, the object with that ID described by the document.

But additionally, the following may be useful within certain applications:

Image files, including "#COMPOUND-IMAGE" as used by PicGrid
Value is the encoded image, which has a width, height, resolution, and some representation of intensity for each channel
Audio files, including "#SGTA"
Value is the encoded MCAS (multi-channel analog signal), which has a length, bitrate, and a mapping of time -> numeric value for each channel
M3U files ("#EXTM3U")
Value is a list of resources, with metadata
TEF files ("#TEF")
Value is the subject of TEF file. If a fragment identifier is provided, it maps exactly to an entry's ID string. The file or identified fragment must include a header with RDF-mapping information for this to be well defined.

Examples of formats whose lexical-to-value mapping is *not* defined by this format: