Thanks Korny.
Ok, the over-ridding theme seems to be: expose state, even if it is
dangerous, but expect consumers to 'do the right thing' and read the
documentation.
I can see that. I guess I have worked (and to be honest, been guilty
myself) with too many people who don't read the documentation, use
auto-complete to find something that looks like it might work and then move
on to the next chunk of wiring things up in XML :).
I think I also got hung up on the 'data as a contract'. The point here is
that I am not returning data, rather I am defining a service. A subtle
difference but an important one I think.
Keep the comments coming!
On 10 May 2013 11:37, Korny Sietsma <ko...@sietsma.com> wrote:
> I would generally handle this sort of encapsulation at the namespace level.
>
> Put (create-woobly) and (add-job) and all the other woobly-related
> functions into a woobly namespace. Also add any functions that access info
> from a woobly bag-o-state, or mutate a woobly to make a woobly-with-extras.
>
> Functions that might dangerously expose internals of a woobly can be made
> private, or possibly you can just document them in a way to warn folks away
> from "bad" behaviour.
>
> While external users of (woobly/create-woobly) can in theory dig into the
> internals of the woobly "object", but it should be relatively obvious that
> this isn't a good idea.
>
> I'd defer making protocols until you actually need polymorphism.
>
> - Korny
>
>
>
> On 10 May 2013 03:03, Colin Yates <colin.ya...@gmail.com> wrote:
>
>> Thanks for all the helpful responses.
>>
>> One reason I want to hide the internals is that I don't want people to
>> add jobs directly to the queue. (add-job) will put a map containing the
>> provided function onto the queue. Not really relevant, but this is so that
>> I can track queue timings that I can later on use to determine how much
>> capacity the system can handle.
>>
>> I am nervous as well about "expose internals but trust people to do the
>> right thing" because in this case, if I was a consumer and saw that queue,
>> particularly given the emphasis about data being the contract etc. then why
>> would I think *not* to use it.
>>
>> I do appreciate the point about not needlessly obfuscating information -
>> this is a slightly different case.
>>
>> Sounds like in this case, either reify is the way to go or maybe return a
>> bad of data but have this stuff in an 'internal' map (i.e. {:internal
>> {:queue...}})
>>
>> Thanks a bunch - really helpful.
>>
>>
>> On 9 May 2013 17:30, James Reeves <ja...@booleanknot.com> wrote:
>>
>>> On 9 May 2013 17:07, Colin Yates <colin.ya...@gmail.com> wrote:
>>>
>>>> The part I am struggling with is how to create a Woobly without
>>>> exposing its internals.
>>>>
>>>
>>> To what end? What's the benefit?
>>>
>>> If you take a look at some internal data structures Clojure uses, like
>>> zippers or protocols, you'll notice that they're just maps. In general
>>> there's no need to try and obfuscate data to stop people from diving into
>>> the internals; just don't provide a public API for the internal parts and
>>> people will get the hint.
>>>
>>> - James
>>>
>>> --
>>> --
>>> 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 a topic in the
>>> Google Groups "Clojure" group.
>>> To unsubscribe from this topic, visit
>>> https://groups.google.com/d/topic/clojure/D2OBBPTxGfY/unsubscribe?hl=en.
>>> To unsubscribe from this group and all its topics, send an email to
>>> clojure+unsubscr...@googlegroups.com.
>>>
>>> For more options, visit https://groups.google.com/groups/opt_out.
>>>
>>>
>>>
>>
>> --
>> --
>> 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.
>>
>> For more options, visit https://groups.google.com/groups/opt_out.
>>
>>
>>
>
>
>
> --
> Kornelis Sietsma korny at my surname dot com http://korny.info
> .fnord { display: none !important; }
>
> --
> --
> 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 a topic in the
> Google Groups "Clojure" group.
> To unsubscribe from this topic, visit
> https://groups.google.com/d/topic/clojure/D2OBBPTxGfY/unsubscribe?hl=en.
> To unsubscribe from this group and all its topics, send an email to
> clojure+unsubscr...@googlegroups.com.
> For more options, visit https://groups.google.com/groups/opt_out.
>
>
>
--
--
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.
For more options, visit https://groups.google.com/groups/opt_out.
