/// <param name="ex">
/// is the union expression. </param>
/// <returns> a new function. </returns>
public virtual object visit(UnionExpr ex)
{
ex.left().accept(this);
ex.right().accept(this);
return(null);
}
/// <summary>
/// Validate a union expression.
/// </summary>
/// <param name="unex">
/// is the expression. </param>
/// <returns> null. </returns>
public virtual object visit(UnionExpr unex)
{
printBinExpr("UNION", unex);
return(null);
}
/// <param name="unex">
/// is the union expression. </param>
/// <returns> a new function. </returns>
public virtual object visit(UnionExpr unex)
{
throw new Exception();
//ICollection args = normalize_bin_args(unex);
//return make_function(new QName("op", "union", OpFunctionLibrary.XPATH_OP_NS), args);
}
