Nix Options – A set of useful Emacs modes and functions for users of Nix and Nix OS.

nixos-options	helm-nixos-options	company-nixos-options	nix-sandbox

Usage

helm-nixos-options

The function helm-nixos-options is the one that you want to bind. You are free to choose where and if you want it global you can have this.

(global-set-key (kbd "C-c C-S-n") 'helm-nixos-options)

It looks like this

The description of the option is shown in the minibuffer

If you want more information, there is a detailed buffer when you press return

There are also other actions like inserting the current match into the buffer

company-nixos-options

Add company-nixos-options to allowed company-mode backends list

(add-to-list 'company-backends 'company-nixos-options)

For now it shows the documentation of the option in a popup-buffer.

nixos-sandbox

Utility functions to work with nix sandboxes.

nix-shell-command composes command that can be executed in the given sandbox
nix-shell executes a command in the given sandbox
nix-compile compiles a program in the given sandbox
nix-find-sandbox searches from the given path upwards until it finds a shell.nix or default.nix file.
nix-current-sandbox searches for a sandbox file starting from the current working directory.
nix-executable-find a replacement for the built-in executable-find. The function searches in the given sandbox for executables.

Flycheck

With this configuration flycheck can find executables of checkers that would be only accessible via nix-shell:

(setq flycheck-command-wrapper-function
        (lambda (command) (apply 'nix-shell-command (nix-current-sandbox) command))
      flycheck-executable-find
        (lambda (cmd) (nix-executable-find (nix-current-sandbox) cmd)))

Haskell Mode

Add these lines to your configuration to allow haskell-mode to look for ghc in the current sandbox.

(setq haskell-process-wrapper-function
        (lambda (args) (apply 'nix-shell-command (nix-current-sandbox) args)))