Prerequisites for IDE Editors

Credits

In order to setup your favorite editor for Haskell/Plutus development you need following components - GHC (haskell compiler) & cabal (build system for haskell projects) - haskell-language-server

GHC & cabal

You have 2 options for setting up the compiler infrastructure: - Using Nix and nix-shell. Assuming you've done setup of plutus for running plutus-playground locally, you already have ghc and cabal binaries available inside nix-shell. - System-wide installation. Generally, if you don't want to run plutus-playground locally and only want to compile Plutus contracts, you can use your existing haskell installation or install the compiler toolchain without Nix. For using this method, follow the instructions on ghcup website.

HSL (haskell-language-server)

IDE-like features like auto-completion, type hints, docs and jump-to-definition are provided by a tool called haskell-language-server. It is a standalone program that implements Language Server Protocol (LSP) for Haskell. Your editor can talk to this program and get the information for showing types, doing auto-completion, etc.

Linux

On Linux, installing the HSL is pretty straightforwad. If you've done Nix setup then you already have haskell-language-server binary on your $PATH inside nix-shell. If you've done installation with ghcup, you can install HSL with following command 

ghcup install hsl
or you can download pre-built binary from releases page. Don't forget to put the binary on your $PATH.

macOS

On macOS, the installation is a bit trickier. Due to linking proglems HSL crashes when your project uses TemplateHaskell (which Plutus uses a lot) (issue, issue). The workaround for this is to compile HSL manually with dynamic linking support.

  1. Make sure you have ghc & cabal installed and available on your $PATH (either locally or within nix-shell)
  2. Clone HSL repo 
    $ git clone https://github.com/haskell/haskell-language-server --recurse-submodules
$ cd haskell-language-server
  3. Make changes to haskell-language-server.cabal file to use dynamic linking (huge shoutout to @nymeron#8182 for finding that). The diff
  4. Find out your ghc version 
    ghc --version
# The Glorious Glasgow Haskell Compilation System, version 8.10.4
  5. Build HSL for your compiler version 
    ./cabal-hls-install hls-<version>
# cabal-hls-install hls-8.10.4
  6. Once the build is done, newly created binary will be located in $HOME/.cabal/bin. If you use nix-shell, make sure that you use right binary since nix-shell provides its own.

Once you have everything set up you can proceed to configuring your editor.