806c281b34
Has a little setup to get the cursor position and map it onto a tree sitter node. The current node is saved in a cursor variable, and a highlight overlay marks the range of the current node in the buffer. Change-Id: I0af56115f928732e993fbefe978a246ca7c757ee Reviewed-on: https://cl.tvl.fyi/c/depot/+/2258 Reviewed-by: lukegb <lukegb@tvl.fyi> Reviewed-by: tazjin <mail@tazj.in> Reviewed-by: Profpatsch <mail@profpatsch.de> Tested-by: BuildkiteCI
108 lines
3.8 KiB
EmacsLisp
108 lines
3.8 KiB
EmacsLisp
;; this is not an actual cursor, just a node.
|
||
;; It’s not super efficient, but cursors can’t be *set* to an arbitrary
|
||
;; subnode, because they can’t access the parent otherwise.
|
||
;; We’d need a way to reset the cursor and walk down to the node?!
|
||
(defvar-local tree-sitter-move--cursor nil
|
||
"the buffer-local cursor used for movement")
|
||
|
||
(defvar-local tree-sitter-move--debug-overlay nil
|
||
"an overlay used to visually display the region currently marked by the cursor")
|
||
|
||
;;;;; TODO: should everything use named nodes? Only some things?
|
||
;;;;; maybe there should be a pair of functions for everything?
|
||
;;;;; For now restrict to named nodes.
|
||
|
||
(defun tree-sitter-move--setup ()
|
||
;; TODO
|
||
(progn
|
||
(tree-sitter-mode t)
|
||
(setq tree-sitter-move--cursor (tsc-root-node tree-sitter-tree))
|
||
(add-variable-watcher
|
||
'tree-sitter-move--cursor
|
||
#'tree-sitter-move--debug-overlay-update)))
|
||
|
||
(defun tree-sitter-move--debug-overlay-update (sym newval &rest _args)
|
||
"variable-watcher to update the debug overlay when the cursor changes"
|
||
(let ((start (tsc-node-start-position newval))
|
||
(end (tsc-node-end-position newval)))
|
||
(symbol-macrolet ((o tree-sitter-move--debug-overlay))
|
||
(if o
|
||
(move-overlay o start end)
|
||
(setq o (make-overlay start end))
|
||
(overlay-put o 'face 'highlight)
|
||
))))
|
||
|
||
(defun tree-sitter-move--debug-overlay-teardown ()
|
||
"Turn of the overlay visibility and delete the overlay object"
|
||
(when tree-sitter-move--debug-overlay
|
||
(delete-overlay tree-sitter-move--debug-overlay)
|
||
(setq tree-sitter-move--debug-overlay nil)))
|
||
|
||
(defun tree-sitter-move--teardown ()
|
||
(setq tree-sitter-move--cursor nil)
|
||
(tree-sitter-move--debug-overlay-teardown)
|
||
(tree-sitter-mode nil))
|
||
|
||
;; Get the syntax node the cursor is on.
|
||
(defun tsc-node-named-node-at-point ()
|
||
(let ((p (point)))
|
||
(tsc-get-named-descendant-for-position-range
|
||
(tsc-root-node tree-sitter-tree) p p)))
|
||
|
||
(defun tsc-get-node-at-point ()
|
||
(let ((p (point)))
|
||
(tsc-get-descendant-for-position-range
|
||
(tsc-root-node tree-sitter-tree) p p)))
|
||
|
||
(defun tsc-get-first-named-node-with-siblings-up (node)
|
||
"Returns the first 'upwards' node that has siblings. That includes the current
|
||
node, so if the given node has siblings, it is returned."
|
||
(let ((has-siblings-p
|
||
(lambda (n)
|
||
(> (tsc-count-named-children (tsc-get-parent n))
|
||
1)))
|
||
(res node))
|
||
(while (not (funcall has-siblings-p res))
|
||
;; TODO tsc-get-parent is called twice, nicer somehow?
|
||
(setq res (tsc-get-parent res)))
|
||
res))
|
||
|
||
(defun tree-sitter-move--set-cursor-to-node (node)
|
||
(setq tree-sitter-move--cursor node))
|
||
|
||
(defun tree-sitter-move--set-cursor-to-node-at-point ()
|
||
(tree-sitter-move--set-cursor-to-node (tsc-get-node-at-point)))
|
||
|
||
(defun tree-sitter-move--move-point-to-node (node)
|
||
(set-window-point
|
||
(selected-window)
|
||
(tsc-node-start-position node)))
|
||
|
||
|
||
;; interactive commands (“do what I expect” section)
|
||
|
||
(defun tree-sitter-move-right ()
|
||
"Moves to the next sibling. If the current node does not have siblings, go
|
||
upwards until something has siblings and then move right."
|
||
(interactive)
|
||
(tree-sitter-move--set-cursor-to-node-at-point)
|
||
(let ((next (tsc-get-next-named-sibling
|
||
(tsc-get-first-named-node-with-siblings-up tree-sitter-move--cursor))))
|
||
(when next
|
||
(tree-sitter-move--set-cursor-to-node next)
|
||
(tree-sitter-move--move-point-to-node next))))
|
||
|
||
; mostly stolen from tree-sitter-mode
|
||
;;;###autoload
|
||
(define-minor-mode tree-sitter-move-mode
|
||
"Minor mode to do cursor movements via tree-sitter"
|
||
:init-value nil
|
||
:lighter " tree-sitter-move"
|
||
(if tree-sitter-move-mode
|
||
(tree-sitter--error-protect
|
||
(progn
|
||
(tree-sitter-move--setup))
|
||
(setq tree-sitter-move-mode nil)
|
||
(tree-sitter-move--teardown))
|
||
(lambda ())
|
||
(tree-sitter-move--teardown)))
|