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Could you explain what you're missing from Rx that isn't already supported by Dart's core library. For example in Dart Iterables and Streams already have: where

by xxgreg 12y ago

Could you explain what you're missing from Rx that isn't already supported by Dart's core library. For example in Dart Iterables and Streams already have: where, skip, take, map, fold, reduce, expand (which is flatMap or mapcat), as well as a few others. https://api.dartlang.org/apidocs/channels/be/dartdoc-viewer/dart:async.Stream https://api.dartlang.org/apidocs/channels/be/dartdoc-viewer/... https://api.dartlang.org/apidocs/channels/be/dartdoc-viewer/dart:core.Iterable https://api.dartlang.org/apidocs/channels/be/dartdoc-viewer/... https://rx.codeplex.com/ https://rx.codeplex.com/

spankalee 12y ago
To me the only thing that's missing is a Property object - a Stream with a current value. I've ended up implementing it a few times already.
danschultz 12y ago
Dart's Stream class is missing many of the composition, transformation and termination methods that you'd find in other FRP libraries. It's also lacking a concept of time-varying values, which to me are important for holding and responding to state changes. Having functions like flatMapLatest, flatMap, combine, merge, scan, and takeUntil are pretty much essential to building any RX heavy application. There are some packages out there that extend Dart's streams to add this behavior. One of which I'm the author of, Frappe. Of course, it'd be nice if Dart included this stuff out of the box. https://github.com/danschultz/frappe https://github.com/danschultz/frappe
- xxgreg 12y ago
  I thought Stream.expand(f) is flatMap. i.e. From docs: "Creates a new stream from this stream that converts each element into zero or more events." Stream.takeWhile(f) is takeUntil with the return value of the f argument negated. But sure, you can always add more features to a core library, the difficult decision is when to stop, and leave the rest to libraries.

by xxgreg 12y ago

spankalee 12y ago

To me the only thing that's missing is a Property object - a Stream with a current value. I've ended up implementing it a few times already.

danschultz 12y ago

Dart's Stream class is missing many of the composition, transformation and termination methods that you'd find in other FRP libraries. It's also lacking a concept of time-varying values, which to me are important for holding and responding to state changes. Having functions like flatMapLatest, flatMap, combine, merge, scan, and takeUntil are pretty much essential to building any RX heavy application. There are some packages out there that extend Dart's streams to add this behavior. One of which I'm the author of, Frappe. Of course, it'd be nice if Dart included this stuff out of the box. https://github.com/danschultz/frappe https://github.com/danschultz/frappe

xxgreg 12y ago
I thought Stream.expand(f) is flatMap. i.e. From docs: "Creates a new stream from this stream that converts each element into zero or more events." Stream.takeWhile(f) is takeUntil with the return value of the f argument negated. But sure, you can always add more features to a core library, the difficult decision is when to stop, and leave the rest to libraries.