According to DFDL-6-078R:
When recognizing expressions:
'{{' as the first characters should be treated as the literal '{' and not a DFDL expression
Test expressionRules03 tests this, and the test fails. I had to comment out the section of the schema that uses '{{' because it causes this error:
Schema Definition Error: Error loading schema(org.xml.sax.SAXParseException; lineNumber: 29; columnNumber: 138; cvc-pattern-valid: Value '{{' is not facet-valid with respect to pattern '({[^\{].*})|({})' for type 'DFDLExpression'.)
test is located in:
./daffodil-test/src/test/resources/edu/illinois/ncsa/daffodil/section23/dfdl_expressions/expressions.tdml
./daffodil-test/src/test/scala/edu/illinois/ncsa/daffodil/section23/dfdl_expressions/TestDFDLExpressions.scala