Use Case: using a Node Expression for sh:hasValue and sh:defaultValue at the same time

[tpluscode]

This may already be implied, but I'd like to spell out a scenario where (the same) Node Expression is set to both hasValue and defaultValue. This will allow engine to validate a property and also set its value if missing

Example: SHACL-SHACL computing and validating sh:conforms

[
  sh:targetClass sh:ValidationReport ;
  sh:property [
    sh:path sh:conforms ;
    sh:datatype xsd:boolean ;
    sh:hasValue _:conforms ;
    sh:defaultValue _:conforms ;
  ] ;
].

_:conforms 
  fn:exists ([
    sh:path ( sh:validationResult sh:severity ) ;
    sh:hasValue sh:Violation ;
  ]) ;
. 

I make the assumption that only violations should actually fail validation.
Even if we do not put such a construct in SHACL-SHACL, an engine which implements Node Expressions could use this method for this or other purposes