SHACL property value rules: using BIND and REPLACE with special characters

[Dan Segal]

Hello,

I am trying to use a property value rule to infer a value from another property.

The use case involves using REGEX to strip out certain strings and special characters.

The logic works OK with alphanumeric characters, but it returns an error on special characters.

For example, the following statement works OK:

sh:values [
      sh:select """

        SELECT ?value2

        WHERE {

            $this <http://www.example.org#property1> ?value1 .

        BIND (REPLACE (?value1, "foo" ,"") AS ?value2)

        }

""" ;
    ];

However, the following statement, which is intended to remove the [ character, returns an error:

sh:values [
      sh:select """

        SELECT ?value2

        WHERE {

            $this <http://www.example.org#property1> ?value1 .

        BIND (REPLACE (?value1, "\\[" ,"") AS ?value2)

        }

""" ;
    ];

The escape characters \\ work OK in a SPARQL query.  However, in the property value rule, they return the following error:

    (SHACL node expression of unknown type: org.apache.jena.query.QueryParseException:... Encountered: '91' (91), after prefix "\"\\")

Is there a different way to indicate escape characters, so that REGEX can be used in the BIND/REPLACE statement?

Thank you,

Dan Segal

[Holger Knublauch]

Hi Dan,

I guess the problem is that the Turtle serialization uses its own escaping mechanism. So if you want to pass \\ to SPARQL you will likely need to escape it twice, using \\\\

Holger

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[Dan Segal]

Hi Holger,

Inserting the additional escape characters - \\\\ - was successful.

Thank you for the suggestion...Much appreciated!

Regards,

Dan