No, I was trying to write a UDF which, when used in a view, could return information gleaned from the full text of the client's request. It would always be executed. This is explained more fully at the SO link I provided.
Since this is apparently is an untenable idea, I have devised another, less elegant work-around by restructuring the view itself. There is a performance penalty but the downstream error is avoided. My fundamental problem is the way the client application generates its SQL statements and there is nothing I do about that -- so, users will just have to accept whatever limitations may result.
Thanks for your help, though!