Hi. > > I am assuming that the main difference between using the "ExceptionContext" > > and passing information in the exception's constructor is that in the > > latter, the information will unconditionally appear in the string returned > > by "getMessage". The contents of the "ExceptionContext" must be retrieved > > manually because, as is the case for iterative solvers, it could lead to a > > huge message. > > > Yes. Or even in some cases to "impossible" messages since it is > totally unthinkable to compute the entries of the matrix underlying > the general linear operator. In fact, for debugging purposes, printing > the operator is not in my view necessary. For example, if the > preconditioned conjugate gradient throws a > NonPositiveDefiniteLinearOperatorException, I just need to know which > one of the operator or its preconditioner was found not to be positive > definite.
Do you mean that the context info for a (hyptohetical) method like doSomething(LinearOperator a, LinearOperator b) would be like offending operator: a or offending operator: b ? If so, is it not enough to just throw the exception? Won't it be obvious which operator is "offending" by looking at the line number in the stack trace? > > > > Thus, when debugging an application, one can catch the exception and loop > > over the context keys using the "getKeys()" method, without needing to need > > the key names in advance. [Thus I would keep the key names "private".] > > > OK, I understand. But we *do* document the keys, don't we? For > example, would the Javadoc of the Conjugate Gradient method state > which keys are used for what purpose? In principle it would not hurt to have more detailed documentation. Alternatively, we could introduce a general comment that "Additional information on the failure is available in the exception context". Best, Gilles --------------------------------------------------------------------- To unsubscribe, e-mail: dev-unsubscr...@commons.apache.org For additional commands, e-mail: dev-h...@commons.apache.org
