;; Copyright (C) 2023 Free Software Foundation, Inc.
-;; Author : 付禹安 (Yuan Fu) <casouri@gmail.com>
+;; Maintainer : 付禹安 (Yuan Fu) <casouri@gmail.com>
;; Keywords : c c++ java javascript rust languages tree-sitter
;; This file is part of GNU Emacs.
;;; Commentary:
;;
-;; For C-like language major modes:
+;; This file contains functions that can be shared by C-like language
+;; major modes, like indenting and filling "/* */" block comments.
+;;
+;; For indenting and filling comments:
;;
;; - Use `c-ts-common-comment-setup' to setup comment variables and
;; filling.
;; - Use simple-indent matcher `c-ts-common-looking-at-star' and
;; anchor `c-ts-common-comment-start-after-first-star' for indenting
;; block comments. See `c-ts-mode--indent-styles' for example.
+;;
+;; For indenting statements:
+;;
+;; - Set `c-ts-common-indent-offset',
+;; `c-ts-common-indent-block-type-regexp', and
+;; `c-ts-common-indent-bracketless-type-regexp', then use simple-indent
+;; offset `c-ts-common-statement-offset' in
+;; `treesit-simple-indent-rules'.
;;; Code:
(declare-function treesit-node-end "treesit.c")
(declare-function treesit-node-type "treesit.c")
+;;; Comment indentation and filling
+
(defun c-ts-common-looking-at-star (_n _p bol &rest _)
"A tree-sitter simple indent matcher.
Matches if there is a \"*\" after BOL."
(setq-local paragraph-separate paragraph-start)
(setq-local fill-paragraph-function #'c-ts-common--fill-paragraph))
+;;; Statement indent
+
+(defvar c-ts-common-indent-offset nil
+ "Indent offset used by `c-ts-common' indent functions.
+
+This should be the symbol of the indent offset variable for the
+particular major mode. This cannot be nil for `c-ts-common'
+statement indent functions to work.")
+
+(defvar c-ts-common-indent-block-type-regexp nil
+ "Regexp matching types of block nodes (i.e., {} blocks).
+
+This cannot be nil for `c-ts-common' statement indent functions
+to work.")
+
+(defvar c-ts-common-indent-bracketless-type-regexp nil
+ "A regexp matching types of bracketless constructs.
+
+These constructs include if, while, do-while, for statements. In
+these statements, the body can omit the bracket, which requires
+special handling from our bracket-counting indent algorithm.
+
+This can be nil, meaning such special handling is not needed.")
+
+(defun c-ts-common-statement-offset (node parent &rest _)
+ "This anchor is used for children of a statement inside a block.
+
+This function basically counts the number of block nodes (i.e.,
+brackets) (defined by `c-ts-mode--indent-block-type-regexp')
+between NODE and the root node (not counting NODE itself), and
+multiply that by `c-ts-common-indent-offset'.
+
+To support GNU style, on each block level, this function also
+checks whether the opening bracket { is on its own line, if so,
+it adds an extra level, except for the top-level.
+
+PARENT is NODE's parent."
+ (let ((level 0))
+ ;; If point is on an empty line, NODE would be nil, but we pretend
+ ;; there is a statement node.
+ (when (null node)
+ (setq node t))
+ ;; If NODE is a opening bracket on its own line, take off one
+ ;; level because the code below assumes NODE is a statement
+ ;; _inside_ a {} block.
+ (when (string-match-p c-ts-common-indent-block-type-regexp
+ (treesit-node-type node))
+ (cl-decf level))
+ ;; Go up the tree and compute indent level.
+ (while (if (eq node t)
+ (setq node parent)
+ node)
+ (when (string-match-p c-ts-common-indent-block-type-regexp
+ (treesit-node-type node))
+ (cl-incf level)
+ (save-excursion
+ (goto-char (treesit-node-start node))
+ ;; Add an extra level if the opening bracket is on its own
+ ;; line, except (1) it's at top-level, or (2) it's immediate
+ ;; parent is another block.
+ (cond ((bolp) nil) ; Case (1).
+ ((let ((parent-type (treesit-node-type
+ (treesit-node-parent node))))
+ ;; Case (2).
+ (and parent-type
+ (or (string-match-p
+ c-ts-common-indent-block-type-regexp
+ parent-type))))
+ nil)
+ ;; Add a level.
+ ((looking-back (rx bol (* whitespace))
+ (line-beginning-position))
+ (cl-incf level)))))
+ (setq level (c-ts-mode--fix-bracketless-indent level node))
+ ;; Go up the tree.
+ (setq node (treesit-node-parent node)))
+ (* level (symbol-value c-ts-common-indent-offset))))
+
+(defun c-ts-mode--fix-bracketless-indent (level node)
+ "Takes LEVEL and NODE and return adjusted LEVEL.
+This fixes indentation for cases shown in bug#61026. Basically
+in C-like syntax, statements like if, for, while sometimes omit
+the bracket in the body."
+ (let ((block-re c-ts-common-indent-block-type-regexp)
+ (statement-re
+ c-ts-common-indent-bracketless-type-regexp)
+ (node-type (treesit-node-type node))
+ (parent-type (treesit-node-type (treesit-node-parent node))))
+ (if (and block-re statement-re node-type parent-type
+ (not (string-match-p block-re node-type))
+ (string-match-p statement-re parent-type))
+ (1+ level)
+ level)))
+
+(defun c-ts-mode--close-bracket-offset (node parent &rest _)
+ "Offset for the closing bracket, NODE.
+It's basically one level less that the statements in the block.
+PARENT is NODE's parent."
+ (- (c-ts-common-statement-offset node parent)
+ (symbol-value c-ts-common-indent-offset)))
+
(provide 'c-ts-common)
;;; c-ts-common.el ends here
;; will set up Emacs to use the C/C++ modes defined here for other
;; files, provided that you have the corresponding parser grammar
;; libraries installed.
-;;
-;; - Use variable `c-ts-mode-indent-block-type-regexp' with indent
-;; offset c-ts-mode--statement-offset for indenting statements.
-;; Again, see `c-ts-mode--indent-styles' for example.
-;;
;;; Code:
;; Labels.
((node-is "labeled_statement") parent-bol 0)
((parent-is "labeled_statement")
- point-min c-ts-mode--statement-offset)
+ point-min c-ts-common-statement-offset)
((match "preproc_ifdef" "compound_statement") point-min 0)
((match "#endif" "preproc_ifdef") point-min 0)
((match "preproc_function_def" "compound_statement") point-min 0)
((match "preproc_call" "compound_statement") point-min 0)
- ;; {} blocks.
- ((node-is "}") point-min c-ts-mode--close-bracket-offset)
- ((parent-is "compound_statement")
- point-min c-ts-mode--statement-offset)
- ((parent-is "enumerator_list")
- point-min c-ts-mode--statement-offset)
- ((parent-is "field_declaration_list")
- point-min c-ts-mode--statement-offset)
-
((parent-is "function_definition") parent-bol 0)
((parent-is "conditional_expression") first-sibling 0)
((parent-is "assignment_expression") parent-bol c-ts-mode-indent-offset)
;; Indent the body of namespace definitions.
((parent-is "declaration_list") parent-bol c-ts-mode-indent-offset)))
+ ;; int[5] a = { 0, 0, 0, 0 };
((parent-is "initializer_list") parent-bol c-ts-mode-indent-offset)
- ((parent-is "if_statement") parent-bol c-ts-mode-indent-offset)
- ((parent-is "for_statement") parent-bol c-ts-mode-indent-offset)
- ((parent-is "while_statement") parent-bol c-ts-mode-indent-offset)
- ((parent-is "switch_statement") parent-bol c-ts-mode-indent-offset)
- ((parent-is "case_statement") parent-bol c-ts-mode-indent-offset)
- ((parent-is "do_statement") parent-bol c-ts-mode-indent-offset)
+ ((parent-is "enumerator_list") point-min c-ts-common-statement-offset)
+ ((parent-is "field_declaration_list") point-min c-ts-common-statement-offset)
+
+ ;; {} blocks.
+ ((node-is "}") point-min c-ts-mode--close-bracket-offset)
+ ((parent-is "compound_statement") point-min c-ts-common-statement-offset)
+ ((node-is "compound_statement") point-min c-ts-common-statement-offset)
+
,@(when (eq mode 'cpp)
`(((node-is "field_initializer_list") parent-bol ,(* c-ts-mode-indent-offset 2)))))))
`((gnu
"labeled_statement")
(not (treesit-node-top-level func "compound_statement")))))
-(defvar c-ts-mode-indent-block-type-regexp
- (rx (or "compound_statement"
- "field_declaration_list"
- "enumerator_list"))
- "Regexp matching types of block nodes (i.e., {} blocks).")
-
-(defvar c-ts-mode--statement-offset-post-processr nil
- "A functions that makes adjustments to `c-ts-mode--statement-offset'.
-
-This is a function that takes two arguments, the current indent
-level and the current node, and returns a new level.
-
-When `c-ts-mode--statement-offset' runs and go up the parse tree,
-it increments the indent level when some condition are met in
-each level. At each level, after (possibly) incrementing the
-offset, it calls this function, passing it the current indent
-level and the current node, and use the return value as the new
-indent level.")
-
-(defun c-ts-mode--statement-offset (node parent &rest _)
- "This anchor is used for children of a statement inside a block.
-
-This function basically counts the number of block nodes (defined
-by `c-ts-mode--indent-block-type-regexp') between NODE and the
-root node (not counting NODE itself), and multiply that by
-`c-ts-mode-indent-offset'.
-
-To support GNU style, on each block level, this function also
-checks whether the opening bracket { is on its own line, if so,
-it adds an extra level, except for the top-level.
-
-PARENT is NODE's parent."
- (let ((level 0))
- ;; If point is on an empty line, NODE would be nil, but we pretend
- ;; there is a statement node.
- (when (null node)
- (setq node t))
- (while (if (eq node t)
- (setq node parent)
- (setq node (treesit-node-parent node)))
- (when (string-match-p c-ts-mode-indent-block-type-regexp
- (treesit-node-type node))
- (cl-incf level)
- (save-excursion
- (goto-char (treesit-node-start node))
- ;; Add an extra level if the opening bracket is on its own
- ;; line, except (1) it's at top-level, or (2) it's immediate
- ;; parent is another block.
- (cond ((bolp) nil) ; Case (1).
- ((let ((parent-type (treesit-node-type
- (treesit-node-parent node))))
- ;; Case (2).
- (and parent-type
- (string-match-p c-ts-mode-indent-block-type-regexp
- parent-type)))
- nil)
- ;; Add a level.
- ((looking-back (rx bol (* whitespace))
- (line-beginning-position))
- (cl-incf level)))))
- (when c-ts-mode--statement-offset-post-processr
- (setq level (funcall c-ts-mode--statement-offset-post-processr
- level node))))
- (* level c-ts-mode-indent-offset)))
-
-(defun c-ts-mode--fix-bracketless-indent (level node)
- "Takes LEVEL and NODE and returns adjusted LEVEL.
-This fixes indentation for cases shown in bug#61026. Basically
-in C/C++, constructs like if, for, while sometimes don't have
-bracket."
- (if (and (not (equal (treesit-node-type node) "compound_statement"))
- (member (treesit-node-type (treesit-node-parent node))
- '("if_statement" "while_statement" "do_statement"
- "for_statement")))
- (1+ level)
- level))
-
-(defun c-ts-mode--close-bracket-offset (node parent &rest _)
- "Offset for the closing bracket, NODE.
-It's basically one level less that the statements in the block.
-PARENT is NODE's parent."
- (- (c-ts-mode--statement-offset node parent)
- c-ts-mode-indent-offset))
-
;;; Font-lock
(defvar c-ts-mode--preproc-keywords
;; Indent.
(when (eq c-ts-mode-indent-style 'linux)
(setq-local indent-tabs-mode t))
- (setq-local c-ts-mode--statement-offset-post-processr
- #'c-ts-mode--fix-bracketless-indent)
+ (setq-local c-ts-common-indent-offset 'c-ts-mode-indent-offset)
+ (setq-local c-ts-common-indent-block-type-regexp
+ (rx (or "compound_statement"
+ "field_declaration_list"
+ "enumerator_list")))
+ (setq-local c-ts-common-indent-bracketless-type-regexp
+ (rx (or "if_statement" "do_statement"
+ "for_statement" "while_statement")))
;; Comment
(c-ts-common-comment-setup)
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