Method atomExpression

@param code @param pcStart @param pcStop @param allowRefresh @param allowUnderflow @param ret -- true return value; may not be a BS @param andNotDeleted IGNORED @return atom bitset @throws ScriptException

(T[] code, int pcStart, int pcStop,
                           boolean allowRefresh, boolean allowUnderflow,
                           Object[] ret, boolean andNotDeleted)