Functions in SPARQL to Manipulate IRIs?

Question

I want to write some reusable SPARQL queries to do things like take an IRI, get the name part (typically after the # sign), modify it (e.g., replace underscores with blank spaces) and put it in the rdfs:label property. This would be useful for Protege which doesn't fill in the rdfs:label if you use user defined IRIs. Or take an IRI with a user defined name, do the same and then replace the user defined IRI with a UUID. I looked in the SPARQL spec for functions to manipulate IRIs and either they don't exist or I'm missing something obvious. I'm posting this to make sure it isn't the latter. I know it is easy to do the equivalent with things like SUBSTR but I'm surprised that there aren't predefined operators to do things like getting the name part of an IRI and getting the base and want to double check before I roll my own.

Answer 1

In case anyone else wants to do this, I figured it out. There are some answers on this site but they are all for SQL or other languages than SPARQL. The following is for classes and it should be obvious how to adapt it for other entities. Note: this works in the Snap SPARQL Plugin for Protege (that's why I use CONSTRUCT rather than INSERT), however, there is a bug in their implementation of SUBSTR so that it uses 0 based indexing rather than 1 based as the spec says. So if you use this in Snap SPARQL change the 1 to a 2.

CONSTRUCT {?c rdfs:label ?lblname.}
WHERE {?c rdfs:subClassOf owl:Thing.
        BIND(STRAFTER(STR(?c), '#') as ?name)
        BIND(REPLACE(?name,"([A-Z])", " $1" ) as ?namewbs)
        BIND (IF (STRSTARTS(?namewbs," "),SUBSTR(?namewbs,1),?namewbs) AS ?lblname)
        FILTER(?c != owl:Thing || ?c != owl:Nothing)}