Evil Ts Mode

This package provides some basic additional actions for evil-mode using the new built-in tree sitter library. The package only works with Emacs 29 or greater. To activate, just run M-x evil-ts-mode. This was so easy to do, that it hardly merits a package. But perhaps it will be useful to someone.

In visual mode, you can select a if/try/etc statement with s. So when you are inside an if statement, the sequence vas will select it. Similarly, f selects a function and c selects a class. Using vax will expand the selection to the nearest parent; ax can be used repeatedly to continue the expansion. On these cases, there is no difference between inner and outer text objects.

In normal state, you can move to the beginning or the end of a class with [c and ]c. Similarly, [f and ]f moves you to the start or end of a function. And [w moves you to the start of a sentence, and ]w to the end (these last two bindings are not great, but ]s is usually taken for navigating spelling errors). I created this package for my own personal use, so the default bindings may not be what you want. Of course, you can change that. The mode map is evil-ts-mode-map.

Adding new objects is simple. Open treesit-explore-mode and find the node of interest. The following example, shows how to add a text object for try or if statements and map it to i:

(require rx)

(evil-define-text-object my-if-or-try (count &optional beg end type)
  (evil-ts-select-obj (rx (or "if" "for" "with" "try") "_statement")))

(keymap-set evil-inner-text-objects-map "i" 'my-if-or-try)
(keymap-set evil-outer-text-objects-map "i" 'my-if-or-try)

Installation

With straight:

(straight-use-package '(evil-ts :type git :host github :repo "foxfriday/evil-ts"))

You can also use the new vc-install functions. This is what I do:

(defun extra-github-install (repo dest &optional branch)
  "Clone BRANCH of REPO in DEST and install."
  (let* ((remote (concat "https://github.com/" repo ".git"))
         (name (nth 1 (string-split repo "/")))
         (pkg (intern name))
         (local (file-name-concat (expand-file-name dest) name))
         (branch (if branch branch "main")))
    (unless (file-directory-p local)
      (vc-clone remote 'Git local branch))
    (unless (package-installed-p pkg)
      (package-vc-install-from-checkout local name))))

(extra-github-install "foxfriday/evil-ts" "~/Repos/emacs")

Troubleshooting

Make sure that you installed the tree sitter modules, and that your Emacs build includes native support for tree sitter. The easiest way to install the modules is to use these scripts. You may also want to activate the built-in tree sitter modes, though that’s not strictly necessary. You do need to let treesit know the location of the modules. All that can be done by adding the following in your init.el.

; required. Assumes that the modules are in your emacs directory, inside
; the subdirectory 'ts'.
(setq treesit-extra-load-path (list (concat user-emacs-directory "ts/")))
; optional, use tree sitter modes.
(setq major-mode-remap-alist '((c++-mode . c++-ts-mode)
                               (c-mode . c-ts-mode)
                               (c-or-c++-mode . c-or-c++-ts-mode)
                               (conf-toml-mode . toml-ts-mode)
                               (csharp-mode . csharp-ts-mode)
                               (css-mode . css-ts-mode)
                               (java-mode . java-ts-mode)
                               (js-json-mode . json-ts-mode)
                               (python-mode . python-ts-mode)
                               (ruby-mode . ruby-ts-mode)
                               (sh-mode . bash-ts-mode)))
; tree-sitter only modes
(add-to-list 'auto-mode-alist '("CMakeLists\\'" . cmake-ts-mode))
(add-to-list 'auto-mode-alist '("Dockerfile\\'" . dockerfile-ts-mode))
(add-to-list 'auto-mode-alist '("\\.go\\'" . go-ts-mode))
(add-to-list 'auto-mode-alist '("/go\\.mod\\'" . go-mod-ts-mode))
(add-to-list 'auto-mode-alist '("\\.rs\\'" . rust-ts-mode))
(add-to-list 'auto-mode-alist '("\\.tsx\\'" . tsx-ts-mode))
(add-to-list 'auto-mode-alist '("\\.ts\\'" . typescript-ts-mode))
(add-to-list 'auto-mode-alist '("\\.y[a]?ml\\'" . yaml-ts-mode))

Similar Packages

Evil-textobj-tree-sitter provides similar functionality without the “Emacs 29 or greater” requirement, and it is available on Melpa. Evil-ts works with the built-in treesit package and therefore requires Emacs 29.