;;; rust-ts-mode.el --- tree-sitter support for Rust -*- lexical-binding: t; -*- ;; Copyright (C) 2022-2023 Free Software Foundation, Inc. ;; Author : Randy Taylor ;; Maintainer : Randy Taylor ;; Created : December 2022 ;; Keywords : rust languages tree-sitter ;; This file is part of GNU Emacs. ;; GNU Emacs is free software: you can redistribute it and/or modify ;; it under the terms of the GNU General Public License as published by ;; the Free Software Foundation, either version 3 of the License, or ;; (at your option) any later version. ;; GNU Emacs is distributed in the hope that it will be useful, ;; but WITHOUT ANY WARRANTY; without even the implied warranty of ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the ;; GNU General Public License for more details. ;; You should have received a copy of the GNU General Public License ;; along with GNU Emacs. If not, see . ;;; Commentary: ;; ;;; Code: (require 'treesit) (eval-when-compile (require 'rx)) (require 'c-ts-common) ; For comment indent and filling. (declare-function treesit-parser-create "treesit.c") (declare-function treesit-induce-sparse-tree "treesit.c") (declare-function treesit-node-child "treesit.c") (declare-function treesit-node-child-by-field-name "treesit.c") (declare-function treesit-node-start "treesit.c") (declare-function treesit-node-type "treesit.c") (declare-function treesit-node-parent "treesit.c") (declare-function treesit-query-compile "treesit.c") (defcustom rust-ts-mode-indent-offset 4 "Number of spaces for each indentation step in `rust-ts-mode'." :version "29.1" :type 'integer :safe 'integerp :group 'rust) (defvar rust-ts-mode--syntax-table (let ((table (make-syntax-table))) (modify-syntax-entry ?+ "." table) (modify-syntax-entry ?- "." table) (modify-syntax-entry ?= "." table) (modify-syntax-entry ?% "." table) (modify-syntax-entry ?& "." table) (modify-syntax-entry ?| "." table) (modify-syntax-entry ?^ "." table) (modify-syntax-entry ?! "." table) (modify-syntax-entry ?@ "." table) (modify-syntax-entry ?~ "." table) (modify-syntax-entry ?< "." table) (modify-syntax-entry ?> "." table) (modify-syntax-entry ?/ ". 124b" table) (modify-syntax-entry ?* ". 23" table) (modify-syntax-entry ?\n "> b" table) (modify-syntax-entry ?\^m "> b" table) table) "Syntax table for `rust-ts-mode'.") (defvar rust-ts-mode--indent-rules `((rust ((parent-is "source_file") point-min 0) ((node-is ")") parent-bol 0) ((node-is "]") parent-bol 0) ((node-is "}") (and parent parent-bol) 0) ((and (parent-is "comment") c-ts-common-looking-at-star) c-ts-common-comment-start-after-first-star -1) ((parent-is "comment") prev-adaptive-prefix 0) ((parent-is "arguments") parent-bol rust-ts-mode-indent-offset) ((parent-is "await_expression") parent-bol rust-ts-mode-indent-offset) ((parent-is "array_expression") parent-bol rust-ts-mode-indent-offset) ((parent-is "binary_expression") parent-bol rust-ts-mode-indent-offset) ((parent-is "block") parent-bol rust-ts-mode-indent-offset) ((parent-is "declaration_list") parent-bol rust-ts-mode-indent-offset) ((parent-is "enum_variant_list") parent-bol rust-ts-mode-indent-offset) ((parent-is "field_declaration_list") parent-bol rust-ts-mode-indent-offset) ((parent-is "field_expression") parent-bol rust-ts-mode-indent-offset) ((parent-is "field_initializer_list") parent-bol rust-ts-mode-indent-offset) ((parent-is "let_declaration") parent-bol rust-ts-mode-indent-offset) ((parent-is "macro_definition") parent-bol rust-ts-mode-indent-offset) ((parent-is "parameters") parent-bol rust-ts-mode-indent-offset) ((parent-is "token_tree") parent-bol rust-ts-mode-indent-offset) ((parent-is "use_list") parent-bol rust-ts-mode-indent-offset))) "Tree-sitter indent rules for `rust-ts-mode'.") (defvar rust-ts-mode--builtin-macros '("concat_bytes" "concat_idents" "const_format_args" "format_args_nl" "log_syntax" "trace_macros" "assert" "assert_eq" "assert_ne" "cfg" "column" "compile_error" "concat" "dbg" "debug_assert" "debug_assert_eq" "debug_assert_ne" "env" "eprint" "eprintln" "file" "format" "format_args" "include" "include_bytes" "include_str" "is_x86_feature_detected" "line" "matches" "module_path" "option_env" "panic" "print" "println" "stringify" "thread_local" "todo" "try" "unimplemented" "unreachable" "vec" "write" "writeln") "Rust built-in macros for tree-sitter font-locking.") (defvar rust-ts-mode--keywords '("as" "async" "await" "break" "const" "continue" "dyn" "else" "enum" "extern" "fn" "for" "if" "impl" "in" "let" "loop" "match" "mod" "move" "pub" "ref" "return" "static" "struct" "trait" "type" "union" "unsafe" "use" "where" "while" (crate) (self) (super) (mutable_specifier)) "Rust keywords for tree-sitter font-locking.") (defvar rust-ts-mode--operators '("!" "!=" "%" "%=" "&" "&=" "&&" "*" "*=" "+" "+=" "," "-" "-=" "->" "." ".." "..=" "..." "/" "/=" ":" ";" "<<" "<<=" "<" "<=" "=" "==" "=>" ">" ">=" ">>" ">>=" "@" "^" "^=" "|" "|=" "||" "?") "Rust operators for tree-sitter font-locking.") (defvar rust-ts-mode--font-lock-settings (treesit-font-lock-rules :language 'rust :feature 'attribute '((attribute_item) @font-lock-preprocessor-face (inner_attribute_item) @font-lock-preprocessor-face) :language 'rust :feature 'bracket '((["(" ")" "[" "]" "{" "}"]) @font-lock-bracket-face) :language 'rust :feature 'builtin `((macro_invocation macro: ((identifier) @font-lock-builtin-face (:match ,(rx-to-string `(seq bol (or ,@rust-ts-mode--builtin-macros) eol)) @font-lock-builtin-face))) ((identifier) @font-lock-type-face (:match "^\\(:?Err\\|Ok\\|None\\|Some\\)$" @font-lock-type-face))) :language 'rust :feature 'comment '(([(block_comment) (line_comment)]) @font-lock-comment-face) :language 'rust :feature 'delimiter '((["," "." ";" ":" "::"]) @font-lock-delimiter-face) :language 'rust :feature 'definition '((function_item name: (identifier) @font-lock-function-name-face) (macro_definition "macro_rules!" @font-lock-constant-face) (macro_definition (identifier) @font-lock-preprocessor-face) (field_declaration name: (field_identifier) @font-lock-property-face) (parameter) @rust-ts-mode--fontify-pattern (let_declaration) @rust-ts-mode--fontify-pattern (for_expression) @rust-ts-mode--fontify-pattern (let_condition) @rust-ts-mode--fontify-pattern (match_arm) @rust-ts-mode--fontify-pattern) :language 'rust :feature 'function '((call_expression function: [(identifier) @font-lock-function-name-face (field_expression field: (field_identifier) @font-lock-function-name-face) (scoped_identifier name: (identifier) @font-lock-function-name-face)]) (generic_function function: [(identifier) @font-lock-function-name-face (field_expression field: (field_identifier) @font-lock-function-name-face) (scoped_identifier name: (identifier) @font-lock-function-name-face)]) (macro_invocation macro: (identifier) @font-lock-preprocessor-face)) :language 'rust :feature 'keyword `([,@rust-ts-mode--keywords] @font-lock-keyword-face) :language 'rust :feature 'number '([(float_literal) (integer_literal)] @font-lock-number-face) :language 'rust :feature 'operator `([,@rust-ts-mode--operators] @font-lock-operator-face) :language 'rust :feature 'string '([(char_literal) (raw_string_literal) (string_literal)] @font-lock-string-face) :language 'rust :feature 'type `((scoped_use_list path: (identifier) @font-lock-constant-face) (scoped_use_list path: (scoped_identifier name: (identifier) @font-lock-constant-face)) ((use_as_clause alias: (identifier) @font-lock-type-face) (:match "^[A-Z]" @font-lock-type-face)) ((use_as_clause path: (identifier) @font-lock-type-face) (:match "^[A-Z]" @font-lock-type-face)) ((use_as_clause path: (scoped_identifier path: (_) name: (identifier) @font-lock-type-face)) (:match "^[A-Z]" @font-lock-type-face)) (use_as_clause path: (scoped_identifier name: (identifier) @default)) ((use_declaration argument: (scoped_identifier path: (_) @font-lock-constant-face name: (identifier) @font-lock-type-face)) (:match "^[A-Z]" @font-lock-type-face)) (use_declaration argument: (scoped_identifier name: (identifier) @default)) (use_declaration argument: (scoped_identifier path: (scoped_identifier path: (_) @font-lock-constant-face name: (identifier) @font-lock-constant-face) name: (identifier) @default)) (use_declaration argument: (scoped_use_list path: (scoped_identifier path: (_) @font-lock-constant-face name: (identifier) @font-lock-constant-face))) ((use_list (identifier) @font-lock-type-face) (:match "^[A-Z]" @font-lock-type-face)) (use_list (identifier) @default) ((use_list (scoped_identifier path: (_) name: (identifier) @font-lock-type-face)) (:match "^[A-Z]" @font-lock-type-face)) (use_list (scoped_identifier path: (_) name: (identifier) @default)) (use_wildcard (scoped_identifier name: (identifier) @font-lock-constant-face)) (enum_variant name: (identifier) @font-lock-type-face) (match_arm pattern: (match_pattern (_ type: (identifier) @font-lock-type-face))) (match_arm pattern: (match_pattern (_ type: (scoped_identifier path: (identifier) @font-lock-type-face)))) (mod_item name: (identifier) @font-lock-constant-face) (primitive_type) @font-lock-type-face (type_identifier) @font-lock-type-face ((scoped_identifier name: (identifier) @font-lock-type-face) (:match "^[A-Z]" @font-lock-type-face)) ((scoped_identifier path: (identifier) @font-lock-type-face) (:match "^[A-Z]" @font-lock-type-face)) ((scoped_identifier path: (identifier) @font-lock-type-face) (:match "^\\(u8\\|u16\\|u32\\|u64\\|u128\\|usize\\|i8\\|i16\\|i32\\|i64\\|i128\\|isize\\|char\\|str\\)$" @font-lock-type-face)) (scoped_identifier path: (_) @font-lock-constant-face name: (identifier) @font-lock-type-face) (scoped_identifier path: (scoped_identifier name: (identifier) @font-lock-constant-face)) (scoped_type_identifier path: (_) @font-lock-constant-face) (scoped_type_identifier path: (scoped_identifier path: (_) @font-lock-constant-face name: (identifier) @font-lock-constant-face)) (type_identifier) @font-lock-type-face ;; Ensure function calls aren't highlighted as types. (call_expression function: (scoped_identifier name: (identifier) @default))) :language 'rust :feature 'property '((field_identifier) @font-lock-property-face (shorthand_field_initializer (identifier) @font-lock-property-face)) ;; Must be under type, otherwise some imports can be highlighted as consants. :language 'rust :feature 'constant `((boolean_literal) @font-lock-constant-face ((identifier) @font-lock-constant-face (:match "^[A-Z][A-Z\\d_]*$" @font-lock-constant-face))) :language 'rust :feature 'variable '((identifier) @font-lock-variable-name-face ;; Everything in a token_tree is an identifier. (token_tree (identifier) @default)) :language 'rust :feature 'escape-sequence :override t '((escape_sequence) @font-lock-escape-face) :language 'rust :feature 'error :override t '((ERROR) @font-lock-warning-face)) "Tree-sitter font-lock settings for `rust-ts-mode'.") (defalias 'rust-ts-mode--fontify-pattern (and (treesit-available-p) `(lambda (node override start end &rest _) (let ((captures (treesit-query-capture (treesit-node-child-by-field-name node "pattern") ,(treesit-query-compile 'rust '((identifier) @id (shorthand_field_identifier) @id))))) (pcase-dolist (`(_name . ,id) captures) (unless (string-match-p "\\`scoped_\\(?:type_\\)?identifier\\'" (treesit-node-type (treesit-node-parent id))) (treesit-fontify-with-override (treesit-node-start id) (treesit-node-end id) 'font-lock-variable-name-face override start end))))))) (defun rust-ts-mode--defun-name (node) "Return the defun name of NODE. Return nil if there is no name or if NODE is not a defun node." (pcase (treesit-node-type node) ("enum_item" (treesit-node-text (treesit-node-child-by-field-name node "name") t)) ("function_item" (treesit-node-text (treesit-node-child-by-field-name node "name") t)) ("impl_item" (let ((trait-node (treesit-node-child-by-field-name node "trait"))) (concat (treesit-node-text trait-node t) (when trait-node " for ") (treesit-node-text (treesit-node-child-by-field-name node "type") t)))) ("mod_item" (treesit-node-text (treesit-node-child-by-field-name node "name") t)) ("struct_item" (treesit-node-text (treesit-node-child-by-field-name node "name") t)) ("type_item" (treesit-node-text (treesit-node-child-by-field-name node "name") t)))) (defun rust-ts-mode--syntax-propertize (beg end) "Apply syntax text property to template delimiters between BEG and END. < and > are usually punctuation, e.g., as greater/less-than. But when used for types, they should be considered pairs. This function checks for < and > in the changed RANGES and apply appropriate text property to alter the syntax of template delimiters < and >'s." (goto-char beg) (while (re-search-forward (rx (or "<" ">")) end t) (pcase (treesit-node-type (treesit-node-parent (treesit-node-at (match-beginning 0)))) ("type_arguments" (put-text-property (match-beginning 0) (match-end 0) 'syntax-table (pcase (char-before) (?< '(4 . ?>)) (?> '(5 . ?<)))))))) ;;;###autoload (define-derived-mode rust-ts-mode prog-mode "Rust" "Major mode for editing Rust, powered by tree-sitter." :group 'rust :syntax-table rust-ts-mode--syntax-table (when (treesit-ready-p 'rust) (treesit-parser-create 'rust) ;; Syntax. (setq-local syntax-propertize-function #'rust-ts-mode--syntax-propertize) ;; Comments. (c-ts-common-comment-setup) ;; Font-lock. (setq-local treesit-font-lock-settings rust-ts-mode--font-lock-settings) (setq-local treesit-font-lock-feature-list '(( comment definition) ( keyword string) ( attribute builtin constant escape-sequence number type) ( bracket delimiter error function operator property variable))) ;; Imenu. (setq-local treesit-simple-imenu-settings `(("Module" "\\`mod_item\\'" nil nil) ("Enum" "\\`enum_item\\'" nil nil) ("Impl" "\\`impl_item\\'" nil nil) ("Type" "\\`type_item\\'" nil nil) ("Struct" "\\`struct_item\\'" nil nil) ("Fn" "\\`function_item\\'" nil nil))) ;; Indent. (setq-local indent-tabs-mode nil treesit-simple-indent-rules rust-ts-mode--indent-rules) ;; Navigation. (setq-local treesit-defun-type-regexp (regexp-opt '("enum_item" "function_item" "impl_item" "struct_item"))) (setq-local treesit-defun-name-function #'rust-ts-mode--defun-name) (treesit-major-mode-setup))) (if (treesit-ready-p 'rust) (add-to-list 'auto-mode-alist '("\\.rs\\'" . rust-ts-mode))) (provide 'rust-ts-mode) ;;; rust-ts-mode.el ends here