Swift for TensorFlow

Swift for TensorFlow: No boundaries.

Swift for TensorFlow is a next-generation platform for machine learning, incorporating the latest research across machine learning, compilers, differentiable programming, systems design, and beyond. This is an early-stage project: it is not feature-complete nor production-ready, but it is ready for pioneers to try in projects, give feedback, and help shape the future!

The Swift for TensorFlow project is currently focusing on 2 kinds of users:

Advanced ML researchers who are limited by current ML frameworks. Swift for TensorFlow's advantages include a seamless integration with a modern general-purpose language, allowing for more dynamic and sophisticated models. Fast abstractions can be developed "in user-space" (as opposed to in C/C++ aka "framework-space"), resulting in modular APIs that can be easily customized.
ML learners who are just getting started with machine learning. Thanks to Swift's support for quality tooling (e.g. context-aware autocomplete), Swift for TensorFlow can be one of the most productive ways to get started learning the fundamentals of machine learning.

Getting started

Using Swift for TensorFlow

Google Colaboratory: The fastest way to get started is to try out Swift for TensorFlow right in your browser. Just open up a tutorial, or start from a blank notebook! Read more in our usage guide.
Install locally: you can download a pre-built Swift for TensorFlow package. After installation, you can follow these step-by-step instructions to build and execute a Swift script on your computer.
Compile from source: If you'd like to customize Swift for TensorFlow or contribute back, follow our instructions on building Swift for TensorFlow from source.

Tutorials

Tutorial	Last Updated
A Swift Tour	March 2019
Python Interoperability	March 2019
Custom Differentiation	March 2019
Model Training Walkthrough	March 2019
Raw TensorFlow Operators	March 2019

Resources

Forums

Please join the swift@tensorflow.org mailing list to hear the latest announcements, get help, and share your thoughts!

Why Swift for TensorFlow?

Swift for TensorFlow is a new way to develop machine learning models. It gives you the power of TensorFlow directly integrated into the Swift programming language. We believe that machine learning paradigms are so important that they deserve first-class language and compiler support.

A fundamental primitive in machine learning is gradient-based optimization: computing function derivatives to optimize parameters. With Swift for TensorFlow, you can easily differentiate functions using differential operators like gradient(of:), or differentiate with respect to an entire model by calling method gradient(in:). These differentiation APIs are not just available for Tensor-related concepts—they are generalized for all types that conform to the Differentiable protocol, including Float, Double, SIMD vectors, and your own data structures.

// Custom differentiable type.
struct Model: Differentiable {
    var w: Float
    var b: Float
    func applied(to input: Float) -> Float {
        return w * input + b
    }
}

// Differentiate using `Differentiable.gradient(at:in:)`.
let model = Model(w: 4.0, b: 3.0)
let (𝛁model, 𝛁input) = model.gradient(at: 2.0) { model, input in
    model.applied(to: input)
}

print(𝛁model) // Model.AllDifferentiableVariables(w: 2.0, b: 1.0)
print(𝛁input) // 4.0

Beyond derivatives, the Swift for TensorFlow project comes with a sophisticated toolchain to make users more productive. You can run Swift interactively in a Jupyter notebook, and get helpful autocomplete suggestions to help you explore the massive API surface of a modern deep learning library. You can get started right in your browser in seconds!

Migrating to Swift for TensorFlow is really easy thanks to Swift's powerful Python integration. You can incrementally migrate your Python code over (or continue to use your favorite Python libraries), because you can easily call your favorite Python library with a familiar syntax:

import TensorFlow
import Python

let np = Python.import("numpy")

let array = np.arange([10, 10])  // Create a 10x10 numpy array.
let tensor = Tensor(numpy: array)  // Seamless integration!

Documentation

Beware: the project is moving very quickly, and thus some of these documents are slightly out of date as compared to the current state-of-the-art.

Overview

Document	Last Updated	Status
Why Swift for TensorFlow?	April 2018	Current
Swift for TensorFlow Design Overview	April 2018	Outdated

Technology deep dive

The Swift for TensorFlow project builds on top of powerful theoretical foundations. For insight into some of the underlying technologies, check out the following documentation.

Document	Last Updated	Status
Differentiable Types	March 2019	Current
Differentiable Functions and Differentiation APIs	March 2019	Current
Dynamic Property Iteration using Key Paths	March 2019	Current
Hierarchical Parameter Iteration and Optimization	March 2019	Current
First-Class Automatic Differentiation in Swift: A Manifesto	October 2018	Outdated
Automatic Differentiation Whitepaper	April 2018	Outdated
Python Interoperability	April 2018	Current
Graph Program Extraction	April 2018	Outdated

Source code

Compiler and standard library development happens on the tensorflow branch of the apple/swift repository.

Additional code repositories that make up the core of the project include:

Swift fork of LLDB: debugger and REPL support.
Deep learning library: high-level API familiar to Keras users.

Swift for TensorFlow is not intended to remain a long-term fork of the official Swift language. Language additions are designed to fit with the direction of Swift and will go through the Swift Evolution process.

Jupyter Notebook support

Jupyter Notebook support for Swift is under development at google/swift-jupyter.

Community

Swift for TensorFlow discussions happen on the swift@tensorflow.org mailing list.

Bugs reports and feature requests

Before reporting an issue, please check the Frequently Asked Questions to see if your question has already been addressed.

For questions about general use or feature requests, please send an email to the mailing list or search for relevant issues in the JIRA issue tracker.

For the most part, the core team's development is also tracked in JIRA.

Contributing

We welcome contributions from everyone. Read the contributing guide for information on how to get started.

Code of conduct

In the interest of fostering an open and welcoming environment, we as contributors and maintainers pledge to making participation in our project and our community a harassment-free experience for everyone, regardless of age, body size, disability, ethnicity, gender identity and expression, level of experience, education, socio-economic status, nationality, personal appearance, race, religion, or sexual identity and orientation.

The Swift for TensorFlow community is guided by our Code of Conduct, which we encourage everybody to read before participating.

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