https://github.com/wuthefwasthat/tapystry

A small python library for handling effects, inspired by redux-saga
https://github.com/wuthefwasthat/tapystry

Last synced: about 1 month ago
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A small python library for handling effects, inspired by redux-saga

• Host: GitHub
• URL: https://github.com/wuthefwasthat/tapystry
• Owner: WuTheFWasThat
• License: mit
• Created: 2020-06-27T18:06:55.000Z (over 4 years ago)
• Default Branch: master
• Last Pushed: 2021-12-01T23:35:07.000Z (about 3 years ago)
• Last Synced: 2024-10-11T15:09:15.817Z (2 months ago)
• Language: Python
• Homepage:
• Size: 89.8 KB
• Stars: 1
• Watchers: 2
• Forks: 2
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
# Tapystry

This is a small library for handling effects, inspired by [redux-saga](https://www.github.com/redux-saga/redux-saga).

## Installation

`pip install tapystry`

## Usage

It's most easily understood by example!

```python

import tapystry as tap

def broadcaster(value):

    yield tap.Broadcast('key', value)

    return "success"

def incrementer():

    value = 0

    while True:

        winner, received_val = yield tap.Race(dict(

            receive=tap.Receive('key'),

            exit=tap.Receive('exit'),

        ))

        if winner == 'exit':

            break

        else:

            assert winner == 'receive'

            value += received_val

    return value

def fn():

    # fork off a strand that increments

    recv_strand = yield tap.CallFork(incrementer)

    # broadcast a value to add

    success = yield tap.Call(broadcaster, (5,))

    assert success == "success"

    # equivalent syntax using yield from

    success = yield from broadcaster(8)

    assert success == "success"

    # forked process is not yet done

    assert not recv_strand.is_done()

    yield tap.Broadcast("exit")

    # this value won't get received

    success = yield tap.Call(broadcaster, (1,))

    assert success == "success"

    value = yield tap.Join(recv_strand)

    return value

assert tap.run(fn) == 13

```

### What's the point?

This lets you isolate side effects really easily.

For example, you could fork a `Strand` that repeatedly polls a database for events.

Then you could have a bunch of independent logic that decides what to do with that.

Everything except the logic touching the database is pure and can be unit tested easily.