----- Original Message ----- From: "Ladislav Lhotka" <[email protected]> Sent: Friday, December 28, 2018 1:03 PM
> On Fri, 2018-12-28 at 11:35 +0000, tom petch wrote: > > ----- Original Message ----- > > From: "Ladislav Lhotka" <[email protected]> > > Sent: Friday, December 28, 2018 7:47 AM <snip> On a different tack, I was looking at teas-types and seeing > > uses path-objective-function_config > > Hang on, is underscore valid? Yes, but why use it? RFC8407 suggests do > > not. > > Maybe the use of the underscore has some meaning? I personally woudn't be so > strict regarding naming conventions, as long as it makes sense to the module > authors and users. And as Randy Presuhn recently explained, there may in fact be > no practical difference between RFC 2119 terms MAY and SHOULD in cases like > this. > > > or > > type union { > > type string { length 0; // empty string } > > type string { pattern ... > > and thinking why? With no length restriction on the pattern, what does > > the complexity of a YANG union add? > > It is either an empty string or a string matching the pattern. Of course, it > would be possible to make the pattern match an empty string. > > > or > > description "Then index of the label restriction list entry."; } > > container label-start { > > must "not(../label-end/te-label/direction) or " > > + "not(te-label/direction) " > > + "or ../label-end/te-label/direction = te-label/direction" { > > error-message "label-start and label-end must have the same > > direction."; > > where the error message tells me what is going on (not the description) > > but I wondered about the second 'not' which I asssume is to cater for > > "(te-label/direction) " > > not having a value. All they want is > > 'start direction must = end direction' > > but it seems you need to be a contortionist to get there. > > A simpler way to express this could be > > must "not(../label-end/te-label/direction != te-label/direction)" > > The inequality test turns false if either of the terms doesn't exist. Ah yes, thanks for that; I was missing the fact that non-existent terms make the inequality false. Tom Petch > Lada > > > > > I would appreciate any comment on this last - is there a simpler way of > > doing it? After which, I shall return to lurking. > > > > Tom Petch > > > > > Lada > > > > > > > Tom Petch > > > > > > > > > /martin > > > > > > > > > > Ladislav Lhotka > Head, CZ.NIC Labs > PGP Key ID: 0xB8F92B08A9F76C67 > _______________________________________________ netmod mailing list [email protected] https://www.ietf.org/mailman/listinfo/netmod
