Write plugins/extensions/whatever to write `import Universum` automatically

[gromakovsky]

For example, when I create a new file in emacs, it has these lines by default:

-- | 

module Pos.Crypto.Patak where

I want to have import Universum line there also.
We need such thing for emacs, vim, something else?

[chshersh]

Ok, Senior Emacs Lisp developer did this. You can insert this code into your ~/.emacs file:

(require 'haskell)

(defun haskell-auto-insert-module-template-universum ()
  "Insert a module template for the newly created buffer."
  (interactive)
  (when (and (= (point-min)
                (point-max))
             (buffer-file-name))
    (insert
     "-- | "
     "\n"
     "\n"
     "module "
     )
    (let ((name (haskell-guess-module-name)))
      (if (string= name "")
          (progn (insert "Main")
                 (shm-evaporate (- (point) 5)
                                (point)))
        (insert name)))
    (insert "\n"
            "       (\n"
            "       ) where\n"
            "\n"
            "import Universum\n"
            "\n"
            )
    (goto-char (point-min))
    (forward-char 4)
    (god-mode)))

(remove-hook 'haskell-mode-hook 'haskell-auto-insert-module-template)
(add-hook 'haskell-mode-hook 'haskell-auto-insert-module-template-universum)

This creates next module for me:

-- | 

module Pos.Crypto.Instances
       (
       ) where

import Universum

[lambdadog]

Unsure whether or not Structured Haskell Mode used to be included in haskell-mode, but at least in 2022, using #'shm-evaporate (as this code does) would need (require 'shm) or (require 'shm-evaporate) to be added, and you would need to ensure the shm/structured-haskell-mode emacs package is installed, as well as haskell-mode.