Optional citation label catalog is a vector of citation label objects.
A citation label object has a scoping URN and a string label. The ordering of these in a catalog is from most specific to most general. Example:
| scope | label |
|---|---|
urn:cts:greekLit:tlg0012.tlg001.wackyItalian:2.494-2.759 |
book/line/catalog unit |
urn:cts:greekLit:tlg0012: |
book/line |
This means that within the specified range of the first specified version, you have a three-tiered citation scheme with the given labels. In the rest of the "Homeric poetry" group, you have a two-tiered scheme labelled "book/line".
I would suggest the following serializations of this structure.
In our XML citation configuration file, an optional section at the beginning of each text group that could look like this:
<citationLabel scope="urn:cts:greekLit:tlg0012.tlg001.wackyItalian:2.494-2.759" labels="book/line/catalog unit"/>
<citationLabel scope="urn:cts:greekLit:tlg0012:" labels="book/line"/>
In .cex files, an optional section that could look like this:
#!ctslabels
urn:cts:greekLit:tlg0012.tlg001.wackyItalian:2.494-2.759#book/line/catalog unit
urn:cts:greekLit:tlg0012:#book/line
In ohco2, the TextRepository object should get a new function labelForPassage that returns Option[String]. It returns the most specific labelling string it can find for a passage reference, or None if there is no label. In the example above, the value for urn:cts:greekLit:tlg0012.tlg001.wackyItalian:2.500 would be the three-tiered string "book/line/catalog unit". The value for urn:cts:greekLit:tlg0012.tlg001.wackyItalian:2.200-2.500 would be a two-tiered string.
URN twiddling should make this relatively easy to implement.