Datafiable is not special, the guidelines (recently refreshed with Rich's input at https://clojure.org/reference/protocols#_guidelines_for_extension) still make sense, but are still just guidelines for your thinking not Laws whose breakage will land you in Clojure Jail.
If you want to make protocol extensions for java time objects to datafiable and put it in a lib, go for it. No one is making anyone else use it. Maybe some day we'll do that in core, maybe not. I'm certain that copying Datafiable to your own version however would lead only to a) confusion and b) a certainty that no one else would actually use it, and that seems like a waste of time. On Friday, January 31, 2020 at 1:24:09 PM UTC-6, Jim foo.bar wrote: > > I tend to agree with you in where the benefit is - it's just that the way > the protocol docs are phrased, and some of the language used in that > mailing discussion from 10 years ago (from authoritative sources like Rich > and Stuart), implies that *no library is to extend clojure.core protocols > to core Java objects*, and that only Clojure itself is allowed do that. > The example Stuart gave back then with the english/spelling-corrector VS > spanish/spelling-corrector is pretty telling... > > Could it perhaps be the case that `Datafiable` is somewhat special in > that, it was conceived for the purpose of open extension by third parties, > and that the protocol extension guidelines don't really apply to it (or > perhaps not as strictly)? > > > Thanks for taking the time :) > > Dimitris > > > On 31/01/2020 01:23, Sean Corfield wrote: > > If your library is intended specifically to provide the ability to > datafy/nav java.time objects then it is something optional that users can > choose to opt into. > > > > The section you meant to link to > https://clojure.org/reference/protocols#_guidelines_for_extension says: “To > minimize conflicts, consider these guidelines” > > > > So they’re a) guidelines and b) just given as a caution to minimize > conflicts. > > > > There are libraries out there already that exist specifically to give > users the option to extend protocols from one library (such as > clojure.java.jdbc or next.jdbc) to Java types to provide customized > behavior, above and beyond the “base versions for common targets” > mentioned in that section provided by the original library. > > > > I see benefit in libraries that extend Clojure’s datafy/nav to new domains > as a narrow purpose that users can opt into. I see much less benefit in > providing the same protocols and function names that core already includes, > targeted to new types, in an isolated way such as this. Perhaps that is > because I’m already using datafy/nav and I find their utility is enhanced > by being extended to other Java types? > > > > Yes, if multiple people write multiple libraries A, B, C that extend > datafy/nav to java.time types and then other libraries X, Y, Z start > pulling in those extenders, consumers of X, Y, Z can be in trouble. > > > > Sean Corfield -- (904) 302-SEAN > An Architect's View -- http://corfield.org/ > > "If you're not annoying somebody, you're not really alive." > -- Margaret Atwood > > > > *From: *dimitris <jimpil1...@gmail.com> > *Sent: *Thursday, January 30, 2020 9:58 AM > *To: *clojure@googlegroups.com > *Subject: *Re: Feedback on datafy/nav project > > > > Well, the official Clojure guidelines are to NOT extend protocols, unless > you own either the protocol of the type(s) [1]. > > In particular these lines: > > *If you are a library developer, you should not extend if you own neither > the protocol nor the target.* > > *You should take particular care when extending protocols included with > Clojure itself.* > > > > Kind regards, > > Dimitris > > [1]: https://clojure.org/reference/protocols#_extend_via_metadata > > > > On 30/01/2020 17:50, Sean Corfield wrote: > > Is there a reason you’ve mirrored those protocols/implementations rather > than just use Clojure’s built-in versions? > > > > As it stands, your library wouldn’t work with other tooling that builds on > Clojure’s datafy/nav (REBL, for example). > > > > Sean Corfield -- (904) 302-SEAN > An Architect's View -- http://corfield.org/ > > "If you're not annoying somebody, you're not really alive." > -- Margaret Atwood > > > > *From: *dimitris <jimpil1...@gmail.com> > *Sent: *Thursday, January 30, 2020 9:05 AM > *To: *Clojure <clojure@googlegroups.com> > *Subject: *Feedback on datafy/nav project > > > > Hi folks, > > > > I'm looking for honest and constructive feedback on [1] - not so much > > about the actual implementation (even though these are welcome too), but > > rather about the general idea of basing everything on top of (mirrored > > versions) `datafy` and `nav` (in this way). There is a TL;DR section at > > the very bottom that describes the approach in 4 short sentences. > > > > Many thanks in advance, > > > > Dimitris > > > > [1]: https://github.com/jimpil/jedi-time > > > > > > -- > > You received this message because you are subscribed to the Google > > Groups "Clojure" group. > > To post to this group, send email to clojure@googlegroups.com > > Note that posts from new members are moderated - please be patient with > your first post. > > To unsubscribe from this group, send email to > > clojure+unsubscr...@googlegroups.com > > For more options, visit this group at > > http://groups.google.com/group/clojure?hl=en > > --- > > You received this message because you are subscribed to the Google Groups > "Clojure" group. > > To unsubscribe from this group and stop receiving emails from it, send an > email to clojure+unsubscr...@googlegroups.com. > > To view this discussion on the web visit > https://groups.google.com/d/msgid/clojure/d0db9e09-6419-2e13-3a0b-9bacf2bbf4fd%40gmail.com > . > > > > -- > You received this message because you are subscribed to the Google > Groups "Clojure" group. > To post to this group, send email to clojure@googlegroups.com > Note that posts from new members are moderated - please be patient with > your first post. > To unsubscribe from this group, send email to > clojure+unsubscr...@googlegroups.com > For more options, visit this group at > http://groups.google.com/group/clojure?hl=en > --- > You received this message because you are subscribed to the Google Groups > "Clojure" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to clojure+unsubscr...@googlegroups.com. > To view this discussion on the web visit > https://groups.google.com/d/msgid/clojure/5e331755.1c69fb81.ff1ad.21cf%40mx.google.com > > <https://groups.google.com/d/msgid/clojure/5e331755.1c69fb81.ff1ad.21cf%40mx.google.com?utm_medium=email&utm_source=footer> > . > > -- > You received this message because you are subscribed to the Google > Groups "Clojure" group. > To post to this group, send email to clojure@googlegroups.com > Note that posts from new members are moderated - please be patient with > your first post. > To unsubscribe from this group, send email to > clojure+unsubscr...@googlegroups.com > For more options, visit this group at > http://groups.google.com/group/clojure?hl=en > --- > You received this message because you are subscribed to the Google Groups > "Clojure" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to clojure+unsubscr...@googlegroups.com. > To view this discussion on the web visit > https://groups.google.com/d/msgid/clojure/3caceeee-a3e9-4b74-bb86-870d3012fa5e%40gmail.com > > <https://groups.google.com/d/msgid/clojure/3caceeee-a3e9-4b74-bb86-870d3012fa5e%40gmail.com?utm_medium=email&utm_source=footer> > . > > > -- > You received this message because you are subscribed to the Google > Groups "Clojure" group. > To post to this group, send email to clojure@googlegroups.com > Note that posts from new members are moderated - please be patient with > your first post. > To unsubscribe from this group, send email to > clojure+unsubscr...@googlegroups.com > For more options, visit this group at > http://groups.google.com/group/clojure?hl=en > --- > You received this message because you are subscribed to the Google Groups > "Clojure" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to clojure+unsubscr...@googlegroups.com. > To view this discussion on the web visit > https://groups.google.com/d/msgid/clojure/5e33818b.1c69fb81.42724.5d42%40mx.google.com > > <https://groups.google.com/d/msgid/clojure/5e33818b.1c69fb81.42724.5d42%40mx.google.com?utm_medium=email&utm_source=footer> > . > > -- You received this message because you are subscribed to the Google Groups "Clojure" group. 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