Package: emacs;
Reported by: Juri Linkov <juri <at> linkov.net>
Date: Tue, 25 Mar 2025 18:44:02 UTC
Severity: normal
Fixed in version 31.0.50
Done: Juri Linkov <juri <at> linkov.net>
Bug is archived. No further changes may be made.
View this message in rfc822 format
From: Juri Linkov <juri <at> linkov.net> To: Yuan Fu <casouri <at> gmail.com> Cc: 77256 <at> debbugs.gnu.org, Vincenzo Pupillo <v.pupillo <at> gmail.com> Subject: bug#77256: Treesit language-at-point Date: Mon, 31 Mar 2025 19:53:14 +0300
[Message part 1 (text/plain, inline)]
>> Do we still need such complicated functions as >> mhtml-ts-mode--language-at-point, js--treesit-language-at-point, etc. >> that duplicate the rules from 'treesit-range-rules' >> when now the default language-at-point function could be implemented >> just as >> >> (treesit-parser-language >> (or (seq-some (lambda (o) (overlay-get o 'treesit-parser)) >> (overlays-at (point) t)) >> treesit-primary-parser)) > > Yeah, we can provide a default language-at-point function now that > determines the “most relevant parser” by embed level. But we should keep > treesit-language-at-point-function because a) it’s already in a release > version and b) we want major modes to be able to customize what parser to > pick at any given point. Ok, so here is a complete patch:
[treesit-parsers-at.patch (text/x-diff, inline)]
diff --git a/lisp/textmodes/mhtml-ts-mode.el b/lisp/textmodes/mhtml-ts-mode.el
index 22c0455a4ee..fdb286fc8c4 100644
--- a/lisp/textmodes/mhtml-ts-mode.el
+++ b/lisp/textmodes/mhtml-ts-mode.el
@@ -221,21 +222,6 @@ mhtml-ts-mode-menu
"Menu bar for `mhtml-ts-mode'."
css-mode--menu)
-;; To enable some basic treesiter functionality, you should define
-;; a function that recognizes which grammar is used at-point.
-;; This function should be assigned to `treesit-language-at-point-function'
-(defun mhtml-ts-mode--language-at-point (point)
- "Return the language at POINT assuming the point is within a HTML buffer."
- (let* ((node (treesit-node-at point 'html))
- (parent (treesit-node-parent node))
- (node-query (format "(%s (%s))"
- (treesit-node-type parent)
- (treesit-node-type node))))
- (cond
- ((equal "(script_element (raw_text))" node-query) (js--treesit-language-at-point point))
- ((equal "(style_element (raw_text))" node-query) 'css)
- (t 'html))))
-
;; Custom font-lock function that's used to apply color to css color
;; The signature of the function should be conforming to signature
;; QUERY-SPEC required by `treesit-font-lock-rules'.
@@ -448,7 +434,7 @@ mhtml-ts-mode-flymake-mhtml
;;;###autoload
(define-derived-mode mhtml-ts-mode html-ts-mode
- '("HTML+" (:eval (let ((lang (mhtml-ts-mode--language-at-point (point))))
+ '("HTML+" (:eval (let ((lang (treesit-language-at (point))))
(cond ((eq lang 'html) "")
((eq lang 'javascript) "JS")
((eq lang 'css) "CSS")))))
@@ -527,10 +520,6 @@ mhtml-ts-mode
(setq-local c-ts-common--comment-regexp
js--treesit-jsdoc-comment-regexp))
-
- ;; Many treesit functions need to know the language at-point.
- ;; So you should define such a function.
- (setq-local treesit-language-at-point-function #'mhtml-ts-mode--language-at-point)
(setq-local prettify-symbols-alist mhtml-ts-mode--prettify-symbols-alist)
;; Indent.
diff --git a/lisp/treesit.el b/lisp/treesit.el
index 54c29326df2..75c04912216 100644
--- a/lisp/treesit.el
+++ b/lisp/treesit.el
@@ -185,15 +185,15 @@ treesit-language-at
This function assumes that parser ranges are up-to-date. It
returns the return value of `treesit-language-at-point-function'
if it's non-nil, otherwise it returns the language of the first
-parser in `treesit-parser-list', or nil if there is no parser.
+parser from `treesit-parsers-at', or the primary parser.
-In a multi-language buffer, make sure
-`treesit-language-at-point-function' is implemented! Otherwise
-`treesit-language-at' wouldn't return the correct result."
+In a multi-language buffer, optionally you can implement
+`treesit-language-at-point-function' to return more correct result."
(if treesit-language-at-point-function
(funcall treesit-language-at-point-function position)
- (when-let* ((parser (car (treesit-parser-list))))
- (treesit-parser-language parser))))
+ (treesit-parser-language
+ (or (car (treesit-parsers-at position))
+ treesit-primary-parser))))
;;; Node API supplement
@@ -247,8 +247,9 @@ treesit-node-at
(parser-or-lang
(let* ((local-parser (car (treesit-local-parsers-at
pos parser-or-lang)))
- (global-parser (car (treesit-parser-list
- nil parser-or-lang)))
+ (global-parser (or (car (treesit-parsers-at
+ pos parser-or-lang))
+ treesit-primary-parser))
(parser (or local-parser global-parser)))
(when parser
(treesit-parser-root-node parser))))
@@ -267,13 +268,10 @@ treesit-node-at
(local-parser
;; Find the local parser with highest
;; embed-level at point.
- (car (seq-sort-by #'treesit-parser-embed-level
- (lambda (a b)
- (> (or a 0) (or b 0)))
- (treesit-local-parsers-at
- pos lang))))
- (global-parser (car (treesit-parser-list
- nil lang)))
+ (car (treesit-local-parsers-at pos lang)))
+ (global-parser (or (car (treesit-parsers-at
+ pos lang))
+ treesit-primary-parser))
(parser (or local-parser global-parser)))
(when parser
(treesit-parser-root-node parser))))))
@@ -851,6 +849,38 @@ treesit--clip-ranges
if (<= start (car range) (cdr range) end)
collect range))
+(defun treesit-parsers-at (&optional pos language with-host local-only)
+ "Return all the non-primary parsers at POS.
+
+POS defaults to point.
+If LANGUAGE is non-nil, only return parsers for LANGUAGE.
+
+If WITH-HOST is non-nil, return a list of (PARSER . HOST-PARSER)
+instead. HOST-PARSER is the host parser which created the PARSER.
+
+If LOCAL-ONLY is non-nil, return only local parsers.
+Local parsers are those which only parse a limited region marked
+by an overlay with non-nil `treesit-parser' property."
+ (let ((res nil))
+ ;; Refer to (ref:local-parser-overlay) for more explanation of local
+ ;; parser overlays.
+ (dolist (ov (overlays-at (or pos (point))))
+ (when-let* ((parser (overlay-get ov 'treesit-parser))
+ (host-parser (or (null with-host)
+ (overlay-get ov 'treesit-host-parser)))
+ (_ (or (null local-only)
+ (overlay-get ov 'treesit-parser-local-p)))
+ (_ (or (null language)
+ (eq (treesit-parser-language parser)
+ language))))
+ (push (if with-host (cons parser host-parser) parser) res)))
+ (seq-sort-by (lambda (p)
+ (treesit-parser-embed-level
+ (or (car-safe p) p)))
+ (lambda (a b)
+ (> (or a 0) (or b 0)))
+ res)))
+
(defun treesit-local-parsers-at (&optional pos language with-host)
"Return all the local parsers at POS.
@@ -862,19 +892,7 @@ treesit-local-parsers-at
If WITH-HOST is non-nil, return a list of (PARSER . HOST-PARSER)
instead. HOST-PARSER is the host parser which created the local
PARSER."
- (let ((res nil))
- ;; Refer to (ref:local-parser-overlay) for more explanation of local
- ;; parser overlays.
- (dolist (ov (overlays-at (or pos (point))))
- (let ((parser (overlay-get ov 'treesit-parser))
- (host-parser (overlay-get ov 'treesit-host-parser))
- (local-p (overlay-get ov 'treesit-parser-local-p)))
- (when (and parser host-parser local-p
- (or (null language)
- (eq (treesit-parser-language parser)
- language)))
- (push (if with-host (cons parser host-parser) parser) res))))
- (nreverse res)))
+ (treesit-parsers-at pos language with-host t))
(defun treesit-local-parsers-on (&optional beg end language with-host)
"Return the list of local parsers that cover the region between BEG and END.
@@ -3135,9 +3159,7 @@ treesit-up-list
(setq parent (treesit-parent-until parent pred)))
(unless parent
- (let ((parsers (seq-keep (lambda (o)
- (overlay-get o 'treesit-host-parser))
- (overlays-at (point) t))))
+ (let ((parsers (mapcar #'cdr (treesit-parsers-at (point) nil t))))
(while (and (not parent) parsers)
(setq parent (treesit-parent-until
(treesit-node-at (point) (car parsers)) pred)
@@ -3887,9 +3929,9 @@ treesit-simple-imenu
(lambda (entry)
(let* ((lang (car entry))
(settings (cdr entry))
- (global-parser (car (treesit-parser-list nil lang)))
- (local-parsers
- (treesit-parser-list nil lang 'embedded)))
+ (global-parser (or (car (treesit-parsers-at nil lang))
+ treesit-primary-parser))
+ (local-parsers (treesit-local-parsers-at nil lang)))
(cons (treesit-language-display-name lang)
;; No one says you can't have both global and local
;; parsers for the same language. E.g., Rust uses
@@ -4029,9 +4074,7 @@ treesit-outline-level
(setq level (1+ level)))
;; Continue counting the host nodes.
- (dolist (parser (seq-keep (lambda (o)
- (overlay-get o 'treesit-host-parser))
- (overlays-at (point) t)))
+ (dolist (parser (mapcar #'cdr (treesit-parsers-at (point) nil t)))
(let* ((node (treesit-node-at (point) parser))
(lang (treesit-parser-language parser))
(pred (alist-get lang treesit-aggregated-outline-predicate)))
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