Dex

Dex (named for "index") is a research language for typed, functional array processing. The goal of the project is to explore:

• Type systems for array programming
• Mathematical program transformations like differentiation and integration
• User-directed compilation to parallel hardware
• Interactive and incremental numerical programming and visualization

To learn more, check out our workshop paper, our tutorial or these example programs:

• Dex prelude
• Mandelbrot set
• Ray tracer
• Estimating pi
• Hamiltonian Monte Carlo
• ODE integrator
• Sierpinski triangle
• Basis function regression
• Brownian bridge

🚨 Dex is an experimental research project at an early stage of development. Expect monstrous bugs and razor-sharp edges!

🤝 Contributions welcome! See our issue tracker for good first issues, or browse by thematic labels.

Dependencies

• Install stack
• Install LLVM 9
  • Ubuntu/Debian: apt-get install llvm-9-dev
  • macOS: brew install llvm@9
    • Make sure llvm@9 is on your PATH before building. Example: export PATH="$(brew --prefix llvm@9)/bin:$PATH"
• Install clang (may be installed together with llvm)
  • Ubuntu/Debian: apt-get install clang
  • macOS: installs with llvm
• Install libpng (often included by default in *nix platforms)
  • Ubuntu/Debian: apt-get install libpng-dev
  • macOS: brew install libpng

Building

• Build Dex in development mode: make
• Run tests in development mode: make tests
• Install a release version of Dex: make install

The default installation directory is $HOME/.local/bin, so make sure to add that directory to $PATH after installing Dex. To install Dex somewhere else, set the PREFIX environment variable before running make install. For example, PREFIX=$HOME make install installs dex in $HOME/bin.

It is convenient to set up a dex alias (e.g. in .bashrc) for running Dex in development mode:

# Linux:
alias dex="stack exec dex -- --lib-path lib"

# macOS:
alias dex="stack exec --stack-yaml=stack-macos.yaml dex -- --lib-path lib"

Haskell Language Server

In order to use HLS with the Haskell code in this project:

• Install ghcup
• Run ghcup install hls
• Create a file in the root dex directory called hie.yaml with the following contents:

cradle:
  stack:
    stackYaml: "./stack-macos.yaml"  # Or stack.yaml if not on MacOS

Unfortunately one cannot dynamically select the stack.yaml file to use based on the environment, and so one has to create an appropriate hie.yaml file manually. This will be ignored by git.

This should work out of the box with Emacs' lsp-haskell package.

Running

• Traditional REPL: dex repl
• Execute script: dex script examples/pi.dx
• Live-updated notebook display dex web examples/pi.dx (html) or dex watch examples/pi.dx (terminal).

License

BSD-3

This is an early-stage research project, not an official Google product.