SEP-0007: Variable Substitution

[afs]

Discussion for SEP-0007: Variable Substitution.

[afs]

"substitution" is the terminology used in the SPARQL spec. But direct replacement has problems. The solution proposed to is put in inline data and join it with the pattern, where patterns can bind variables (Basic Graph Patterns, Property Path Expressions, Graph)

For (?x = 23), the BGP { ?s :p ?x } becomes { ?s :p ?x . VALUES ?x { 23 } }.

Would inject be a better name? There is no substitution/replacement going on.

(There are several different ways to put in the values, and the order of the join can be reversed because the inline data only occurs when a variable will cause a binding.)

[namedgraph]

Is ParameterizedSparqlString using direct replacement? Will it be affected if these changes are implemented?

[afs]

Parametrization is different.

SEP-0007 is for LATERAL joins and EXISTS.

Please ask on the Apache Jena users mailing list (or read the source code) about impact.