Parinfer Mode

About Smart Mode

Currently this project is rewriting for providing smart mode on branch `smart`.

Demo

What Is Parinfer
Installation
Indent And Paren Modes
Configurations
Credits
License
Contribution

What Is Parinfer

Parinfer is a proof-of-concept editor mode for Lisp programming languages. It will infer some changes to keep Parens and Indentation inline with one another. Parinfer consists of two modes:

Indent Mode: Indent Mode gives you full control of indentation, while Parinfer corrects parens.
Paren Mode: Paren Mode gives you full control of parens, while Parinfer corrects indentation.

To learn more about Parinfer, please take a look at its home page.

And the parinfer-mode is the implementation on Emacs with parinfer-elisp.

Installation

Parinfer is available on MELPA(and MELPA Stable) now, I recommend to install with use-package.

Add following code to your .emacs or init.el.

(use-package parinfer
  :ensure t
  :bind
  (("C-," . parinfer-toggle-mode))
  :init
  (progn
    (setq parinfer-extensions
          '(defaults       ; should be included.
            pretty-parens  ; different paren styles for different modes.
            evil           ; If you use Evil.
            lispy          ; If you use Lispy. With this extension, you should install Lispy and do not enable lispy-mode directly.
            paredit        ; Introduce some paredit commands.
            smart-tab      ; C-b & C-f jump positions and smart shift with tab & S-tab.
            smart-yank))   ; Yank behavior depend on mode.
    (add-hook 'clojure-mode-hook #'parinfer-mode)
    (add-hook 'emacs-lisp-mode-hook #'parinfer-mode)
    (add-hook 'common-lisp-mode-hook #'parinfer-mode)
    (add-hook 'scheme-mode-hook #'parinfer-mode)
    (add-hook 'lisp-mode-hook #'parinfer-mode)))

Indent And Paren Modes

Toggle Indent Mode and Paren Mode with command parinfer-toggle-mode.

Avoid unexpect buffer changes.

Whenever you switch to Indent Mode, parinfer-mode will correct all parens of current buffer.

After opening a file, the parinfer-mode enable Indent Mode if it won’t make any changes. Otherwise, Paren Mode will be enabled, you can switch to Indent Mode manually later.

Alternatively, you can use parinfer-diff command to see how will Indent Mode modify the buffer with Ediff.

And there are some keybindings in Ediff:

Key	Description
`q`	Quit diff.
`b`	B->A in Ediff, this can apply change to your origin code.
`ra`	Restore A in Ediff, this can revert change.
`n`	Move to next difference.
`p`	Move to previous difference.

Also, There’s a command parinfer-auto-fix to fix wrong indentation for whole buffer. (Only works with balanced parens)

Configurations

parinfer-auto-switch-indent-mode

(setq parinfer-auto-switch-indent-mode nil)  ;; default

t for enable, Parinfer will auto switch to Indent Mode whenever parens are balance in Paren Mode.

parinfer-auto-switch-indent-mode-when-closing

(setq parinfer-auto-switch-indent-mode-when-closing nil)  ;; default

t for enable, Parinfer will auto switch to Indent Mode when the inserted close parens (), ], }) balance the parens of current sexp.

parinfer-delay-invoke-threshold

(setq parinfer-delay-invoke-threshold 6000)  ;; default

When the length of text for processing is longer than this, Parinfer will process text after a idle delay instead of process immediately.

parinfer-delay-invoke-idle

(setq parinfer-delay-invoke-idle 0.3)  ;; default

The idle seconds before Parinfer processing text on large sexp.

parinfer-extensions

(setq parinfer-extensions '(defaults pretty-parens smart-yank))

The extensions that will be enabled. The list could contain followings:

Extension	Function
defaults	Should be enabled, basic compatibility
pretty-parens	Use dim style for Indent Mode, rainbow delimiters for Paren Mode
smart-yank	Yank will preserve indentation in Indent Mode, will preserve parens in Paren Mode
smart-tab	`C-f` & `C-b` on empty line will goto next/previous import indentation.
paredit	Introduce some paredit commands from paredit-mode.
lispy	Integration with Lispy.
evil	Integration with Evil.
one	Experimental on fuzz Indent Mode and Paren Mode. Not recommanded.

parinfer-lighters

(setq parinfer-lighters '(" Parinfer:Indent" . "Parinfer:Paren"))

Troubleshooting

If Parinfer seems to be indenting incorrectly, ensure indent-tabs-mode is set to nil via (setq-default indent-tabs-mode nil). While Parinfer’s theoretical model is able to correctly handle indentation with tabs, parinfer-mode can currently only handle indentation using spaces.

Credits

shaunlebron: Create Parinfer.
oakmac: Bring Parinfer to Emacs with parinfer-elisp.
tumashu: Help me a lot in writing this plugin.
purcell & syohex: Advice and Tips for writing emacs plugin

Contribution

Please open an issue if there’s any bug or suggestion, and PR is welcomed!

License

parinferlib.el from parinfer-elisp, is licensed under the ISC.

Rest part licensed under the GPLv3.

MassMessage/parinfer-mode