Robust And Fast Functional IO Toolkit

Raffiot is small (almost) dependency-free python library providing some usual functional tools. It currently provides

• an easy-to-use IO monad which is stack-safe, fast, support asynchronous, concurrent, parallel programming, has many other features.
• a Resource data type for easy but reliable resource management.
• a Result data structure to represent errors

Demo

For a demo, just type this in a terminal:

curl https://raw.githubusercontent.com/chrilves/raffiot.py/main/demos/raffiot_demo.sh | /bin/sh

This demo runs 4 computations in parallel. It demonstrates how simple concurrent and parallel programing is in raffiot.

Note that this command will install raffiot in your current Python environment

Documentation

Guide

The guide is online at https://chrilves.github.io/raffiot.py/index.html.

API

The API is online at https://chrilves.github.io/raffiot.py/api/index.html.

Features

• pure python: Raffiot is written entirely in Python 3.7+.
• small: it is just a few small files.
• (almost) dependency-free: it only depends on typing-extensions (for the @final annotation).
• crystal clear code

IO

• stack safe: you just won't run into stack overflows anymore.
• fast: you won't notice the overhead.
• dependency injection made easy: make some context visible from anywhere.
• simple asynchronous and concurrent programming: full support of synchronous, asynchronous and concurrent programming with the same simple API.
• railway-oriented programming: clean and simple failure management.
• distinction between expected and unexpected failures: some failures are part of your program's normal behaviour (errors) while others are show something terribly wrong happened (panics). Yes, that's heavily inspired by Rust.

Resource

Python has the with construction, but Resource goes a step further.

• easy user-defined resource creation: just provide some open and close function.
• composability: the resource you want to create depends on another resource? Not a problem, you can compose resources the way you want. It scales.
• failures handling in resources: Resource has everything IO has, including its wonderful failure management.

Result

Did I mention Railway-Oriented Programming? Result is represent the 3 possible result of a computation:

• Ok(value): the computation successfully computed the this value.
• Error(error): the computation failed on some expected failure error, probably from the business domain.
• Panic(exception): the computation failed on some unexpected failure exception.