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25 lines
929 B
Markdown
25 lines
929 B
Markdown
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# Want
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- [Crates.io](https://crates.io/crates/want)
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- [Docs](https://docs.rs/want)
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A `Future`s channel-like utility to signal when a value is wanted.
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Futures are supposed to be lazy, and only starting work if `Future::poll`
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is called. The same is true of `Stream`s, but when using a channel as
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a `Stream`, it can be hard to know if the receiver is ready for the next
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value.
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Put another way, given a `(tx, rx)` from `futures::sync::mpsc::channel()`,
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how can the sender (`tx`) know when the receiver (`rx`) actually wants more
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work to be produced? Just because there is room in the channel buffer
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doesn't mean the work would be used by the receiver.
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This is where something like `want` comes in. Added to a channel, you can
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make sure that the `tx` only creates the message and sends it when the `rx`
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has `poll()` for it, and the buffer was empty.
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## License
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`want` is provided under the MIT license. See [LICENSE](LICENSE).
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