jasonzoladz / purescript-rxjs Goto Github PK

observable creation is effectful and should be defined as such

Lots of functions like https://pursuit.purescript.org/packages/purescript-rxjs/0.2.0/docs/RxJS.Observable are wrong and work differently regarding if optimisation is on or off.

fromArray :: forall a e. Array a -> Eff (vdom::VDOM|e) (Observable a)

instead of

fromArray :: forall a. Array a -> Observable a

(✏️ edited: remove the BUG suffix)

interval :: forall e. Int -> Eff (vdom::VDOM|e) (Observable Int)

instead of

interval :: Int -> Observable Int

etc

We already have an instance for Semigroup as well as for Alt and Plus. Defining an instance would be as simple as adding a mempty = _empty.

I'd love to see how I could integrate this project into mine :)
Not exactly sure how to do that right now, so any kind of documentation would be nice

Right now when I call

subscribe subject observable

I get the following error:

Could not match type
Record
with type
BehaviorSubject
while trying to match type

{ next :: forall e. a -> Eff e Unit
, error :: forall e. Error -> Eff e Unit
, completed :: forall e. Unit -> Eff e Unit
}

with BehaviorSubject a

Full stacktrace:

TypeError: tryCatchTarget.apply is not a function
at tryCatcher (/Users/luka/proj/purescript-rxjs/node_modules/rxjs/util/tryCatch.js:6:31)
at WindowSubscriber.openWindow (/Users/luka/proj/purescript-rxjs/node_modules/rxjs/operator/windowWhen.js:115:72)
at new WindowSubscriber (/Users/luka/proj/purescript-rxjs/node_modules/rxjs/operator/windowWhen.js:74:14)
at WindowOperator.call (/Users/luka/proj/purescript-rxjs/node_modules/rxjs/operator/windowWhen.js:59:33)
at Observable.subscribe (/Users/luka/proj/purescript-rxjs/node_modules/rxjs/Observable.js:42:22)
at /Users/luka/proj/purescript-rxjs/output/RxJS.Observable/foreign.js:38:11
at __do (/Users/luka/proj/purescript-rxjs/output/Test.Main/index.js:30:57)
at /Users/luka/proj/purescript-rxjs/output/Control.Monad.Aff/foreign.js:269:16
at /Users/luka/proj/purescript-rxjs/output/Test.Unit/foreign.js:23:7
at /Users/luka/proj/purescript-rxjs/output/Control.Monad.Aff/foreign.js:214:12

import RxJS.ReplaySubject (just, debounceTime, send, subscribeNext)
import RxJS.Subscription (unsubscribe)

      pure { changeObservable   : just "" # debounceTime 500
      --- ...

              { changeObservable, search } <- readState this
              subscription <- subscribeNext search changeObservable
              unsubscribe subscription

I put unsubscribe right after subscribeNext for testing this issue. Handler search is working, everything works as expected but unsubscribe here causes this exception:

TypeError: sub is undefined Subscription.js:10
exports.unsubscribe/< Subscription.js:10

That is:

// module RxJS.Subscription

var Rx = require('rxjs');

exports.unsubscribe = function(sub){
  return function(){
    sub.unsubscribe();
  };
}

Currently startWith requires an Array. My thoughts here were, that every item of the Array would be prepended to the Observable, however what actually happens is that just the Array get prepended. This of course completely breaks the type safety and will throw errors at runtime.

I see two solutions right now, either change the type signature to:

foreign import startWith :: forall a. a -> Observable a -> Observable a

or change the underlying JS code to actually parse the array and prepend all the items individually.

We could of course have both as well, with something like startWith and startWithAllor startWithMany.

I've fixed this in my own version, and will gladly send a PR if you decide to go down of these paths. :)

Looks like it's required here:

But if this is needed in tests, maybe a newtype instance would remove the need for it. Otherwise it seems like I can't build this package without this installed.

I can't fix types when I subscribe like here.

How can one subscribe with subscribe, not subscribeNext?

Full stack trace:

TypeError: obs.subscribe is not a function
at /Users/luka/proj/purescript-rxjs/output/RxJS.Observable/foreign.js:38:11
at __do (/Users/luka/proj/purescript-rxjs/output/Test.Main/index.js:33:57)
at /Users/luka/proj/purescript-rxjs/output/Control.Monad.Aff/foreign.js:269:16
at /Users/luka/proj/purescript-rxjs/output/Test.Unit/foreign.js:23:7
at /Users/luka/proj/purescript-rxjs/output/Control.Monad.Aff/foreign.js:214:12
at /Users/luka/proj/purescript-rxjs/output/Control.Monad.Aff/foreign.js:176:17
at /Users/luka/proj/purescript-rxjs/output/Control.Monad.Aff/foreign.js:182:25
at /Users/luka/proj/purescript-rxjs/output/Control.Monad.Aff/foreign.js:275:5
at /Users/luka/proj/purescript-rxjs/output/Control.Monad.Aff/foreign.js:176:17
at /Users/luka/proj/purescript-rxjs/output/Control.Monad.Aff/foreign.js:176:17

I've noticed that usually when we have observables they're often effectful. FromEvent or create are effectful and really most are, especially when dealing with Ajax or the Dom.

I think a Monad transformer would go a long way to ease those pains and reduce boilerplate.

Pleaseeeee..

Right now we have concat for semigroup and merge for Alt. I think we should make it consistent across type classes. My vote goes for merge as concat is rarely used if ever.

There currently seems to be a wrapper for defaultIfEmpty on the js side of things, but none on the purs side of things.

full stack trace:

TypeError: obs.subscribe is not a function
at /Users/luka/proj/purescript-rxjs/output/RxJS.Observable/foreign.js:38:11
at __do (/Users/luka/proj/purescript-rxjs/output/Test.Main/index.js:33:57)
at /Users/luka/proj/purescript-rxjs/output/Control.Monad.Aff/foreign.js:269:16
at /Users/luka/proj/purescript-rxjs/output/Test.Unit/foreign.js:23:7
at /Users/luka/proj/purescript-rxjs/output/Control.Monad.Aff/foreign.js:214:12
at /Users/luka/proj/purescript-rxjs/output/Control.Monad.Aff/foreign.js:176:17
at /Users/luka/proj/purescript-rxjs/output/Control.Monad.Aff/foreign.js:182:25
at /Users/luka/proj/purescript-rxjs/output/Control.Monad.Aff/foreign.js:275:5
at /Users/luka/proj/purescript-rxjs/output/Control.Monad.Aff/foreign.js:176:17
at /Users/luka/proj/purescript-rxjs/output/Control.Monad.Aff/foreign.js:176:17