···
It exposes a set of helpers to create and transform sources and output sinks, meaning it helps you to turn an event source or an
iterable set of data into streams, and manipulate these streams.
Reason has been becoming increasingly popular, but it's missing a good pattern for streams that feels native to the language.
The functional nature of callbags make them a perfect starting point to fix this, and to introduce a reactive programming
pattern to a language that is well suited for it.
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Hence `Wonka` is a library that aims to make complex streams of data easy to deal with.
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This library also attempts to support as many Reason/JS environments as possible, which makes the adoption of streams across
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multiple projects a lot easier. Hence `Wonka` is a library that aims to make complex streams of data easy to deal with.
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`Wonka` is not only compatible with Reason/Bucklescript, but out of the box with other environments as well.
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- Reason/OCaml Bucklescript
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- Reason/OCaml `bs-native`
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In summary, it should work in any TypeScript/Flow/Reason/OCaml environment with full type safety.
Install the library first: `yarn add wonka` or `npm install --save wonka`,
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Then add `wonka` to `bs-dependencies` in your `bsconfig.json` file like so:
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For Bucklescript you will also need to add `wonka` to `bs-dependencies` in your `bsconfig.json` file like so:
···
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Writing your first stream is very easy! Let's suppose you would like to create a stream from a list, filter out some values,
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then map over the remaining ones, and lastly iterate over the final values.
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This can be done with a few operators that might remind you of functions you would also call on iterables.
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let example = [1, 2, 3, 4, 5, 6];
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Wonka.fromList(example)
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|> Wonka.filter((.x) => x mod 2 === 0)
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|> Wonka.map((.x )=> x * 2)
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|> Wonka.forEach((.x) => print_endline(string_of_int(x)));
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/* prints: 4, 8, 12 */
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To explain what's going on:
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- `fromList` creates a pullable source with values from the list
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- `filter` only lets even values through
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- `map` multiplies the values by `2`
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- `forEach` pulls values from the resulting source and prints them
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As you can see, all helpers that we've used are exposed on the `Wonka` module.
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But if we would like to use JavaScript-based APIs, then we need to use the `WonkaJs` module.
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Let's look at the same example, but instead of a list we will use an `interval` stream.
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This stream will output ascending numbers starting from `0` indefinitely.
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We will code the same example as before but we'd like the `interval` to push
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a new number every `50ms` and to stop after seven values.
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WonkaJs.interval(50)
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|> Wonka.filter((.x) => x mod 2 === 0)
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|> Wonka.map((.x) => x * 2)
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|> Wonka.forEach((.x) => print_endline(string_of_int(x)));
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/* prints: 4, 8, 12 */
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The last three functions stay the same, but we are now using `interval` as our source.
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This is a listenable source, meaning that it pushes values downwards when it sees fit.
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And the `take` operator tells our source to stop sending values after having received seven
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And already you have mastered all the basics of `Wonka` and learned about a couple of its operators!
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I am currently still working on getting some documentation up and running. Those will contain:
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This is still a work-in-progress but will contain full information on the following
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across all supported languages:
- The API, i.e. a list of all helpers
···
- Developer Guides (How to write a source/operator/sink)
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Stay tuned and read the signature files in the meantime please:
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- [wonka.rei](./src/wonka.rei)
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- [wonkaJs.rei](./src/wonka.rei)
kitten.sh