mirror of
git://git.sv.gnu.org/emacs.git
synced 2025-12-05 22:20:24 -08:00
Add baseline tree-sitter indent rule for C-like languages
I found a really good baseline indent rule that handles a wide range of situations very well. Now major modes can just start with this rule and add exceptions on top. This is worth mentioning in the manual, but that'll be a large change, and doesn't have to be included in this commit. * lisp/progmodes/c-ts-common.el: (c-ts-common-list-indent-style): New variable. (c-ts-common--standalone-parent): (c-ts-common--prev-standalone-sibling): (c-ts-common-parent-ignore-preproc): (c-ts-common-baseline-indent-rule): New function. * lisp/treesit.el (treesit--indent-prev-line-node): New function. (treesit-simple-indent-presets): Add new preset.
This commit is contained in:
Yuan Fu
parent
4afdb7e80f
commit
e37cd4fa59
2 changed files with 177 additions and 0 deletions
|
|
@ -532,6 +532,169 @@ characters on the current line."
|
|||
(setq node (treesit-node-parent node)))
|
||||
(* level (symbol-value c-ts-common-indent-offset))))
|
||||
|
||||
;;; Baseline indent rule
|
||||
|
||||
(defvar c-ts-common-list-indent-style 'align
|
||||
"Intructs `c-ts-common-baseline-indent-rule' how to indent lists.
|
||||
|
||||
If the value is `align', indent lists like this:
|
||||
|
||||
const a = [
|
||||
1, 2, 3
|
||||
4, 5, 6,
|
||||
];
|
||||
|
||||
If the value is `simple', indent lists like this:
|
||||
|
||||
const a = [
|
||||
1, 2, 3,
|
||||
4, 5, 6,
|
||||
];")
|
||||
|
||||
(defun c-ts-common--standalone-parent (parent)
|
||||
"Find the first parent that starts on a new line.
|
||||
Start searching from PARENT, so if PARENT satisfies the condition, it'll
|
||||
be returned. Return the starting position of the parent, return nil if
|
||||
no parent satisfies the condition."
|
||||
(save-excursion
|
||||
(catch 'term
|
||||
(while parent
|
||||
(goto-char (treesit-node-start parent))
|
||||
(when (looking-back (rx bol (* whitespace))
|
||||
(line-beginning-position))
|
||||
(throw 'term (point)))
|
||||
(setq parent (treesit-node-parent parent))))))
|
||||
|
||||
(defun c-ts-common--prev-standalone-sibling (node)
|
||||
"Return the previous sibling of NODE that starts on a new line.
|
||||
Return nil if no sibling satisfies the condition."
|
||||
(save-excursion
|
||||
(setq node (treesit-node-prev-sibling node 'named))
|
||||
(goto-char (treesit-node-start node))
|
||||
(while (and node
|
||||
(goto-char (treesit-node-start node))
|
||||
(not (looking-back (rx bol (* whitespace))
|
||||
(pos-bol))))
|
||||
(setq node (treesit-node-prev-sibling node 'named)))
|
||||
node))
|
||||
|
||||
(defun c-ts-common-parent-ignore-preproc (node)
|
||||
"Return the parent of NODE, skipping preproc nodes."
|
||||
(let ((parent (treesit-node-parent node))
|
||||
(pred (if (treesit-thing-defined-p
|
||||
'preproc (or (and node (treesit-node-language node))
|
||||
(treesit-parser-language
|
||||
treesit-primary-parser)))
|
||||
'preproc
|
||||
"preproc")))
|
||||
(while (and parent (treesit-node-match-p parent pred))
|
||||
(setq parent (treesit-node-parent parent)))
|
||||
parent))
|
||||
|
||||
(defun c-ts-common-baseline-indent-rule (node parent bol &rest _)
|
||||
"Baseline indent rule for C-like languages.
|
||||
|
||||
NODE PARENT, BOL are like in other simple indent rules.
|
||||
|
||||
This rule works as follows:
|
||||
|
||||
Let PREV-NODE be the largest node that starts on previous line,
|
||||
basically the NODE we get if we were indenting previous line.
|
||||
|
||||
0. Closing brace aligns with first parent that starts on a new line.
|
||||
|
||||
1. If PREV-NODE and NODE are siblings, align this line to previous
|
||||
line (PREV-NODE as the anchor, and offset is 0).
|
||||
|
||||
2. If PARENT is a list, ie, (...) [...], align with NODE's first
|
||||
sibling. For the first sibling and the closing paren or bracket, indent
|
||||
according to `c-ts-common-list-indent-style'. This rule also handles
|
||||
initializer lists like {...}, but initializer lists doesn't respect
|
||||
`c-ts-common-list-indent-style'--they always indent in the `simple'
|
||||
style.
|
||||
|
||||
3. Otherwise, go up the parse tree from NODE and look for a parent that
|
||||
starts on a new line. Use that parent as the anchor and indent one
|
||||
level. But if the node is a top-level construct (ignoring preprocessor
|
||||
nodes), don't indent it.
|
||||
|
||||
This rule works for a wide range of scenarios including complex
|
||||
situations. Major modes should use this as the fallback rule, and add
|
||||
exception rules before it to cover the cases it doesn't apply.
|
||||
|
||||
This rule tries to be smart and ignore proprocessor node in some
|
||||
situations. By default, any node that has \"proproc\" in its type are
|
||||
considered a preprocessor node. If that heuristic is inaccurate, define
|
||||
a `preproc' thing in `treesit-thing-settings', and this rule will use
|
||||
the thing definition instead."
|
||||
(let ((prev-line-node (treesit--indent-prev-line-node bol))
|
||||
(offset (symbol-value c-ts-common-indent-offset)))
|
||||
(cond
|
||||
;; Condition 0.
|
||||
((and (treesit-node-match-p node "}")
|
||||
(treesit-node-match-p (treesit-node-child parent 0) "{"))
|
||||
(cons (c-ts-common--standalone-parent parent)
|
||||
0))
|
||||
;; Condition 1.
|
||||
((and (treesit-node-eq (treesit-node-parent prev-line-node)
|
||||
parent)
|
||||
(not (treesit-node-match-p node (rx (or ")" "]")))))
|
||||
(cons (treesit-node-start prev-line-node)
|
||||
0))
|
||||
;; Condition 2.
|
||||
((treesit-node-match-p (treesit-node-child parent 0)
|
||||
(rx (or "(" "[")))
|
||||
(let ((first-sibling (treesit-node-child parent 0 'named)))
|
||||
(cond
|
||||
;; Closing delimeters.
|
||||
((treesit-node-match-p node (rx (or ")" "]")))
|
||||
(if (eq c-ts-common-list-indent-style 'align)
|
||||
(cons (treesit-node-start (treesit-node-child parent 0))
|
||||
0)
|
||||
(cons (c-ts-common--standalone-parent parent)
|
||||
0)))
|
||||
;; First sibling.
|
||||
((treesit-node-eq node first-sibling)
|
||||
(if (eq c-ts-common-list-indent-style 'align)
|
||||
(cons (treesit-node-start (treesit-node-child parent 0))
|
||||
1)
|
||||
(cons (c-ts-common--standalone-parent parent)
|
||||
offset)))
|
||||
;; Not first sibling
|
||||
(t (cons (treesit-node-start
|
||||
(or (c-ts-common--prev-standalone-sibling node)
|
||||
first-sibling))
|
||||
0)))))
|
||||
;; Condition 2 for initializer list, only apply to
|
||||
;; second line. Eg,
|
||||
;;
|
||||
;; return { 1, 2, 3,
|
||||
;; 4, 5, 6, --> Handled by this condition.
|
||||
;; 7, 8, 9 }; --> Handled by condition 1.
|
||||
((and (treesit-node-match-p (treesit-node-child parent 0) "{")
|
||||
(treesit-node-prev-sibling node 'named))
|
||||
;; If first sibling is a comment, indent like code; otherwise
|
||||
;; align to first sibling.
|
||||
(if (treesit-node-match-p
|
||||
(treesit-node-child parent 0 'named)
|
||||
c-ts-common--comment-regexp 'ignore-missing)
|
||||
(cons (c-ts-common--standalone-parent parent)
|
||||
offset)
|
||||
(cons (treesit-node-start
|
||||
(treesit-node-child parent 0 'named))
|
||||
0)))
|
||||
;; Before we fallback to condition 3, make sure we don't indent
|
||||
;; top-level stuff.
|
||||
((treesit-node-eq (treesit-parser-root-node
|
||||
(treesit-node-parser parent))
|
||||
(c-ts-common-parent-ignore-preproc node))
|
||||
(cons (pos-bol) 0))
|
||||
;; Condition 3.
|
||||
(t (cons (c-ts-common--standalone-parent parent)
|
||||
offset)))))
|
||||
|
||||
|
||||
|
||||
(provide 'c-ts-common)
|
||||
|
||||
;;; c-ts-common.el ends here
|
||||
|
|
|
|||
|
|
@ -1589,6 +1589,14 @@ should take the same argument as MATCHER or ANCHOR. If it matches,
|
|||
return a cons (ANCHOR-POS . OFFSET), where ANCHOR-POS is a position and
|
||||
OFFSET is the indent offset; if it doesn't match, return nil.")
|
||||
|
||||
(defun treesit--indent-prev-line-node (pos)
|
||||
"Return the largest node on the previous line of POS."
|
||||
(save-excursion
|
||||
(goto-char pos)
|
||||
(when (eq (forward-line -1) 0)
|
||||
(back-to-indentation)
|
||||
(treesit--indent-largest-node-at (point)))))
|
||||
|
||||
(defvar treesit-simple-indent-presets
|
||||
(list (cons 'match
|
||||
(lambda
|
||||
|
|
@ -1639,6 +1647,12 @@ OFFSET is the indent offset; if it doesn't match, return nil.")
|
|||
(lambda (node &rest _)
|
||||
(string-match-p
|
||||
type (or (treesit-node-type node) "")))))
|
||||
;; FIXME: Add to manual.
|
||||
(cons 'prev-line-is (lambda (type)
|
||||
(lambda (_n _p bol &rest _)
|
||||
(treesit-node-match-p
|
||||
(treesit--indent-prev-line-node bol)
|
||||
type))))
|
||||
(cons 'field-is (lambda (name)
|
||||
(lambda (node &rest _)
|
||||
(string-match-p
|
||||
|
|
|
|||
Loading…
Add table
Add a link
Reference in a new issue