While a snip belongs to a editor, the editor may store extra information about a snip in some specialized way. When the snip is to be encoded, this extra information needs to be put into a editor data object so that the extra information can be encoded as well. In a text editor, extra information can be associated with ranges of items, as well as snips.
Just as a snip must be associated with a snip class to be decoded (see Snip Classes), a editor data object needs a editor data class for decoding. Every editor data class object should be added to the global editor data class list, returned by get-the-editor-data-class-list.
To store and load information about a snip or region in a editor:
When deriving the new editor-data-class% class, pick a new unique name to identify the encoded data. All names beginning with ``wx'' are reserved for internal use. By tagging extra data with a unique name, the normal editor content can be safely decoded in a editor that does not support the extra data.