vscode.md

VS Code Extensions

Install the following extensions within VS Code.

• Haskell
• stylish-haskell
• hoogle-vscode

Read on for details and usage info.

The Haskell Extension

The Haskell extension is the most important extension out of the bunch, it supports the following

• syntax highlighting
• auto complete
• jump to definition (Alt + left click)
• type info on hover
• function documentation on hover
• code suggestion

If the Haskell extension doesn't work, here's a few things you can try:

• Install Haskell Language Server by hand:
  • By using ghcup

    ghcup install hls
    
    # or for a specific version
    ghcup install hls <version>
    

  • By installing manually from source
    • clone https://github.com/haskell/haskell-language-server
    • Run:

      stack ./install.hs hls
      
      # or for a specific version:
      stack ./install.hs hls-<version>
      

• From inside VSCode, manually specify path to haskell-language-server executable, it's either ~/.ghcup/bin/haskell-language-server-<version> or ~/.local/bin/haskell-language-server.

Stylish Haskell

stylish-haskell is a decent Haskell code formatter.

The extension requires the actual tool be installed:

stack build --copy-compiler-tool stylish-haskell

In Settings, make sure:

• Formatter Provider is set,
• VSCode formats on
  • file save, and
  • on import

Saving file or pasting imports will auto-format.

Default shortcut is Alt + Shift + f, or type format document in command palette.

Hoogle

This extension allows you to search hoogle within VS Code.

Default shortcut is Alt + Shift + h, or type hoogle search in command palette.

Hasklig

This makes your operators pretty.

Download Hasklig.

Install the fonts in OSX's Font Book

Add the following confiugration in VS Code.

"[haskell]": {
  "editor.fontFamily": "Hasklig",
  "editor.fontLigatures": true
}