How to use

substituteVar

method

in

org.apache.hyracks.algebricks.core.algebra.expressions.ScalarFunctionCallExpression

public static void prepareVarAndExpression(List<String> field, LogicalVariable resVar, List<LogicalVariable> vars,
    List<Mutable<ILogicalExpression>> assignExpressions, List<Mutable<ILogicalExpression>> varRefs,
    IVariableContext context, SourceLocation sourceLoc) {
  VariableReferenceExpression dummyVarRef = new VariableReferenceExpression(DUMMY_VAR);
  dummyVarRef.setSourceLocation(sourceLoc);
  ScalarFunctionCallExpression f = createFieldAccessExpression(dummyVarRef, field, sourceLoc);
  f.substituteVar(DUMMY_VAR, resVar);
  assignExpressions.add(new MutableObject<ILogicalExpression>(f));
  LogicalVariable v = context.newVar();
  vars.add(v);
  if (varRefs != null) {
    VariableReferenceExpression vRef = new VariableReferenceExpression(v);
    vRef.setSourceLocation(sourceLoc);
    varRefs.add(new MutableObject<ILogicalExpression>(vRef));
  }
}