BNODE(string) and joins

Hi,

I'm implementing a SPARQL engine in Elixir ([1], [2]). Currently, I'm implementing the interpretation of group graph patterns and have the following question an the handling of blank nodes generated with `BNODE(string)`. When performing the merge of two solutions for a `join`, which of the two merged solutions should the merged solution be based on with respect to `BNODE(string)`? For example, let's say I have two sub groups using the `BNODE(string)` function to generate bnodes for the same string, which would result due to the locality of the `BNODE` function different bnodes. So, when the `BNODE` function is now called in the outer group above the two subgroups, again with the same string, what bnode should be returned? 

Kind regards,
Marcel Otto

[1] https://github.com/marcelotto/sparql-ex
[2] https://lists.w3.org/Archives/Public/public-lod/2018Sep/att-0035/00-part - announcement about the whole project on the public-lod mailing list

Received on Thursday, 4 October 2018 21:40:09 UTC