Hmm, union types are JSON-serializable elsewhere (e.g. JSON.NET, although they are uuuugly in JSON), so just something that eventually needs doing I suppose.
What conversion method did you have in mind that's not hard? On Friday, August 12, 2016 at 1:59:43 PM UTC-5, OvermindDL1 wrote: > > I entirely missed that. ^.^ > > Hmm, is interesting. Flags take Json'able types so those would not be > passable there, would need to convert first, but not hard. > > > > On Friday, August 12, 2016 at 12:53:36 PM UTC-6, Kasey Speakman wrote: >> >> I did that if you look at link to marcosh's github I posted above. >> >> On Friday, August 12, 2016 at 1:50:12 PM UTC-5, OvermindDL1 wrote: >>> >>> Hmm, I'd be curious if you could whip up a full compileable example, say >>> a Multi-Counter project example we could paste into elm-try. Perhaps mark >>> things that are boilerplate and could be hoisted out to a parent library >>> too so we can ignore those? :-) >>> >>> >>> On Friday, August 12, 2016 at 12:15:20 PM UTC-6, Kasey Speakman wrote: >>>> >>>> Skimming through the code, it looks like batch commands will happen in >>>> order. The mentioned `mailbox.push` was from the Elm source code. >>>> >>>> Also, I fleshed out an example with both a clean separation and using >>>> event sourcing. I posted it with some commentary on marcosh's github >>>> <https://github.com/marcosh/marcosh.github.io/issues/1>. >>>> >>>> I like the terminology in this example much better than my previous >>>> examples, especially because `Action` was a previous concept in Elm. >>>> >>>> type Act = Increment | Decrement >>>> >>>> type Fact = Incremented Int | Decremented Int >>>> >>>> type Msg = Perform Act | Apply Fact >>>> >>>> perform : Act -> Model -> Cmd Msg >>>> >>>> apply : Fact -> Model -> Model >>>> >>>> update : Msg -> Model -> (Model, Cmd Msg) >>>> update msg model = >>>> case msg of >>>> Perform act -> >>>> (model, perform act model) >>>> >>>> Apply fact -> >>>> (apply fact model, Cmd.none) >>>> >>>> >>>> The Facts here are also idempotent >>>> <https://en.wikipedia.org/wiki/Idempotence> (no dependency on previous >>>> values). That's not as important in this example, but can as its extended. >>>> >>>> On Friday, August 12, 2016 at 9:15:23 AM UTC-5, OvermindDL1 wrote: >>>>> >>>>> Will your pushed command appear after or before a potentially pushed >>>>> 'other' command, say from an incoming port, or button click? That is the >>>>> part I am not sure about yet (not read enough Elm internals 'quite' yet). >>>>> >>>>> On Thursday, August 11, 2016 at 6:31:06 PM UTC-6, Kasey Speakman wrote: >>>>>> >>>>>> Checked the current implementation of Cmd.batch and it appears >>>>>> sequential (`mailbox.push`). Ordering guarantees are not documented so I >>>>>> suppose they shouldn't be depended on. But otherwise, the one I coded >>>>>> above >>>>>> that guarantees Act doesn't change the model and Evt doesn't have >>>>>> effects >>>>>> would work. >>>>>> >>>>>> On Thursday, August 11, 2016 at 6:33:39 PM UTC-5, Kasey Speakman >>>>>> wrote: >>>>>>> >>>>>>> Yes, that's why I said back to square one if Cmd.batch isn't >>>>>>> ordered. The only thing this is guaranteeing (and the only intended >>>>>>> guarantee) is that the messages which only update the model are >>>>>>> separated >>>>>>> from the ones which cause effects. The ones which cause effects produce >>>>>>> ones which update the model, same as always. >>>>>>> >>>>>>> It occurs to me that some of the benefit of event sourcing the UI >>>>>>> could be gained by adding features to the TTD, since it has the magic >>>>>>> which >>>>>>> ignores Cmds on replay. Some are already listed as ideas at >>>>>>> http://debug.elm-lang.org/. I'd still have to keep the messages in >>>>>>> my model and provide a way for the user to transmit them in a bug >>>>>>> report. >>>>>>> But if I could load them in the TTD, that would make repro a snap. >>>>>>> >>>>>>> On Thursday, August 11, 2016 at 5:22:05 PM UTC-5, OvermindDL1 wrote: >>>>>>>> >>>>>>>> Isn't `doSideEffects` basically just the current `update` function >>>>>>>> though? Except it is returning a list of changes (via message) to >>>>>>>> perform >>>>>>>> to a model instead of doing it in-place? What is this saving >>>>>>>> precisely? >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> On Thursday, August 11, 2016 at 4:05:57 PM UTC-6, Kasey Speakman >>>>>>>> wrote: >>>>>>>>> >>>>>>>>> Actually, I'd probably use a List instead of Maybe on the >>>>>>>>> immediately returned event(s). >>>>>>>>> >>>>>>>>> doSideEffects : Act -> Model -> (List Evt, Cmd Evt) >>>>>>>>> doSideEffects act model = >>>>>>>>> case act of >>>>>>>>> UpdateCustomer customer -> >>>>>>>>> ( [ CustomerUpdateRequested ] >>>>>>>>> , callServerWithCustomer customer >>>>>>>>> ) >>>>>>>>> >>>>>>>>> ... >>>>>>>>> >>>>>>>>> updateModel : Evt -> Model -> Model >>>>>>>>> ... -- implementation as previous >>>>>>>>> >>>>>>>>> update : Msg -> Model -> (Model, Cmd Msg) >>>>>>>>> update msg model = >>>>>>>>> case msg of >>>>>>>>> Action act -> >>>>>>>>> let >>>>>>>>> (events, command) = doSideEffects act model >>>>>>>>> in >>>>>>>>> (List.foldr updateModel model events, Cmd.map Evt command) >>>>>>>>> >>>>>>>>> Event evt -> >>>>>>>>> (updateModel evt model, Cmd.none) >>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>>> On Thursday, August 11, 2016 at 4:26:03 PM UTC-5, Kasey Speakman >>>>>>>>> wrote: >>>>>>>>>> >>>>>>>>>> Yes, that was the goal. That way the UI state is utterly >>>>>>>>>> deterministic / reproducible in isolation of all outside services. >>>>>>>>>> >>>>>>>>>> That's a good point on the race conditions. I only use Cmd.batch >>>>>>>>>> because it's the facility that came to mind. (I'm still getting >>>>>>>>>> acquainted >>>>>>>>>> with Elm.) I don't know if Cmd.batch makes any ordering guarantee. >>>>>>>>>> >>>>>>>>>> If not we'd be more or less back to square one. Abuse `update` to >>>>>>>>>> do both things. >>>>>>>>>> >>>>>>>>>> doSideEffects: Act -> Model -> (Maybe Evt, Cmd Evt) >>>>>>>>>> doSideEffects act model = >>>>>>>>>> case act of >>>>>>>>>> UpdateCustomer customer -> >>>>>>>>>> (Just CustomerUpdateRequested, callServerWithCustomer >>>>>>>>>> customer) >>>>>>>>>> >>>>>>>>>> ... >>>>>>>>>> >>>>>>>>>> updateModel: Evt -> Model -> Model >>>>>>>>>> ... -- implementation as previous >>>>>>>>>> >>>>>>>>>> maybeUpdateModel: Maybe Evt -> Model -> Model >>>>>>>>>> maybeUpdateModel evtOpt model = >>>>>>>>>> case evtOpt of >>>>>>>>>> Nothing -> >>>>>>>>>> model >>>>>>>>>> >>>>>>>>>> Just evt -> >>>>>>>>>> updateModel evt model >>>>>>>>>> >>>>>>>>>> update : Msg -> Model -> (Model, Cmd Msg) >>>>>>>>>> update msg model = >>>>>>>>>> case msg of >>>>>>>>>> Action act -> >>>>>>>>>> let >>>>>>>>>> (eventNow, command) = doSideEffects act model >>>>>>>>>> in >>>>>>>>>> (maybeUpdateModel eventNow model, Cmd.map Evt command) >>>>>>>>>> >>>>>>>>>> Event evt -> >>>>>>>>>> (updateModel evt model, Cmd.none) >>>>>>>>>> >>>>>>>>>> So this should apply an event immediately if one is needed for >>>>>>>>>> the action. But it still keeps the model updating events separate. >>>>>>>>>> >>>>>>>>>> These immediate events would be seen by a userland event-store >>>>>>>>>> implementation (which is underneath updateModel), but I bet the TTD >>>>>>>>>> wouldn't see it since it doesn't come from Elm. >>>>>>>>>> >>>>>>>>>> On Thursday, August 11, 2016 at 3:43:36 PM UTC-5, OvermindDL1 >>>>>>>>>> wrote: >>>>>>>>>>> >>>>>>>>>>> So you really are wanting to hard device events into two >>>>>>>>>>> different ones, those that can *only* alter the model, and those >>>>>>>>>>> that can >>>>>>>>>>> *only* send commands (which may call ones that alter the model). >>>>>>>>>>> Unsure if >>>>>>>>>>> it might actually happen but might have to take into account >>>>>>>>>>> possible race >>>>>>>>>>> conditions for if other messages appear before your other expected >>>>>>>>>>> ones are >>>>>>>>>>> processed through? Easier to do that atomically all at once? >>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>> On Thursday, August 11, 2016 at 2:25:22 PM UTC-6, Kasey Speakman >>>>>>>>>>> wrote: >>>>>>>>>>>> >>>>>>>>>>>> doSideEffects above would also have to map Cmd Evt to Cmd Msg. >>>>>>>>>>>> >>>>>>>>>>> -- You received this message because you are subscribed to the Google Groups "Elm Discuss" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
