;;; java-ts-mode.el --- tree-sitter support for Java -*- lexical-binding: t; -*- ;; Copyright (C) 2022-2025 Free Software Foundation, Inc. ;; Author : Theodor Thornhill ;; Maintainer : Theodor Thornhill ;; Created : November 2022 ;; Keywords : java 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 . ;;; Tree-sitter language versions ;; ;; java-ts-mode has been tested with the following grammars and version: ;; - tree-sitter-java: v0.23.5 ;; ;; We try our best to make builtin modes work with latest grammar ;; versions, so a more recent grammar has a good chance to work too. ;; Send us a bug report if it doesn't. ;;; Commentary: ;; ;; If the tree-sitter doxygen grammar is available, then the comment ;; blocks can be highlighted according to this grammar. ;;; Code: (require 'treesit) (eval-when-compile (require 'rx)) (require 'c-ts-common) ; For comment indent and filling. (treesit-declare-unavailable-functions) (add-to-list 'treesit-language-source-alist '(java "https://github.com/tree-sitter/tree-sitter-java" :commit "94703d5a6bed02b98e438d7cad1136c01a60ba2c") t) (add-to-list 'treesit-language-source-alist '(doxygen "https://github.com/tree-sitter-grammars/tree-sitter-doxygen" :commit "1e28054cb5be80d5febac082706225e42eff14e6") t) (defcustom java-ts-mode-indent-offset 4 "Number of spaces for each indentation step in `java-ts-mode'." :version "29.1" :type 'integer :safe 'integerp :group 'java) (defcustom java-ts-mode-method-chaining-indent-offset 8 "Indent offset for method chaining in `java-ts-mode'." :version "31.1" :type 'integer :safe 'integerp :group 'java) (defcustom java-ts-mode-enable-doxygen nil "Enable doxygen syntax highlighting. If Non-nil, enable doxygen based font lock for comment blocks. This needs to be set before enabling `java-ts-mode'; if you change the value after enabling `java-ts-mode', toggle the mode off and on again." :version "31.1" :type 'boolean :safe 'booleanp :group 'java) (defvar java-ts-mode--syntax-table (let ((table (make-syntax-table))) ;; Taken from the cc-langs version (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 ?\240 "." table) (modify-syntax-entry ?/ ". 124b" table) (modify-syntax-entry ?* ". 23" table) (modify-syntax-entry ?\n "> b" table) (modify-syntax-entry ?\^m "> b" table) (modify-syntax-entry ?@ "'" table) table) "Syntax table for `java-ts-mode'.") (defun java-ts-mode--standalone-predicate (node) "Java's standalone predicate. Return t if NODE is on the start of a line." (save-excursion (goto-char (treesit-node-start node)) (if (looking-back (rx bol (* whitespace) (? ".")) (pos-bol)) t (back-to-indentation) (when (eq (char-after) ?.) (point))))) (defun java-ts-mode--first-line-on-multi-line-string (_node parent _bol &rest _) "Simple-indent matcher for the first line in a multi-line string block. PARENT and BOL are the as in other matchers." (and (treesit-node-match-p parent "multiline_string_fragment") (save-excursion ;; Less than 2 newlines between point and string start. (not (search-backward "\n" (treesit-node-start parent) t 2))))) (defvar java-ts-mode--indent-rules `((java ((parent-is "program") column-0 0) ((match "}" "element_value_array_initializer") parent-bol 0) ((node-is ,(format "\\`%s\\'" (regexp-opt '("constructor_body" "class_body" "interface_body" "block" "switch_block" "array_initializer")))) parent-bol 0) ((node-is "}") standalone-parent 0) ((node-is ")") parent-bol 0) ((node-is "else") parent-bol 0) ((node-is "]") 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) (java-ts-mode--first-line-on-multi-line-string parent-bol java-ts-mode-indent-offset) ((parent-is "multiline_string_fragment") prev-adaptive-prefix 0) ((match "\"\"\"" "string_literal" nil 1) prev-adaptive-prefix 0) ((parent-is "text_block") no-indent) ((parent-is "class_body") column-0 c-ts-common-statement-offset) ((parent-is "array_initializer") parent-bol java-ts-mode-indent-offset) ((parent-is "annotation_type_body") column-0 c-ts-common-statement-offset) ((parent-is "interface_body") column-0 c-ts-common-statement-offset) ((parent-is "constructor_body") standalone-parent java-ts-mode-indent-offset) ((parent-is "enum_body_declarations") parent-bol 0) ((parent-is "enum_body") column-0 c-ts-common-statement-offset) ((parent-is "switch_block") standalone-parent java-ts-mode-indent-offset) ((parent-is "record_declaration_body") column-0 c-ts-common-statement-offset) ((query "(method_declaration (block _ @indent))") parent-bol java-ts-mode-indent-offset) ((query "(method_declaration (block (_) @indent))") parent-bol java-ts-mode-indent-offset) ((parent-is "local_variable_declaration") parent-bol java-ts-mode-indent-offset) ((parent-is "expression_statement") parent-bol java-ts-mode-indent-offset) ((match "type_identifier" "field_declaration") parent-bol 0) ((parent-is "field_declaration") parent-bol java-ts-mode-indent-offset) ((parent-is "return_statement") parent-bol java-ts-mode-indent-offset) ((parent-is "variable_declarator") parent-bol java-ts-mode-indent-offset) ((match ">" "type_arguments") parent-bol 0) ((parent-is "type_arguments") parent-bol java-ts-mode-indent-offset) ((parent-is "method_invocation") parent-bol java-ts-mode-method-chaining-indent-offset) ((parent-is "switch_rule") parent-bol java-ts-mode-indent-offset) ((parent-is "switch_label") parent-bol java-ts-mode-indent-offset) ((parent-is "ternary_expression") parent-bol java-ts-mode-indent-offset) ((parent-is "lambda_expression") parent-bol java-ts-mode-indent-offset) ((parent-is "element_value_array_initializer") parent-bol java-ts-mode-indent-offset) ((parent-is "function_definition") parent-bol 0) ((parent-is "conditional_expression") first-sibling 0) ((parent-is "assignment_expression") parent-bol 2) ((parent-is "binary_expression") parent 0) ((parent-is "parenthesized_expression") first-sibling 1) ((parent-is "argument_list") parent-bol java-ts-mode-indent-offset) ((parent-is "annotation_argument_list") parent-bol java-ts-mode-indent-offset) ((parent-is "modifiers") parent-bol 0) ;; ((parent-is "formal_parameters") parent-bol java-ts-mode-indent-offset) ;; ((parent-is "formal_parameter") parent-bol 0) ((parent-is "init_declarator") parent-bol java-ts-mode-indent-offset) ((parent-is "if_statement") parent-bol java-ts-mode-indent-offset) ((parent-is "for_statement") parent-bol java-ts-mode-indent-offset) ((parent-is "while_statement") parent-bol java-ts-mode-indent-offset) ((parent-is "switch_statement") parent-bol java-ts-mode-indent-offset) ((parent-is "case_statement") parent-bol java-ts-mode-indent-offset) ((parent-is "labeled_statement") parent-bol java-ts-mode-indent-offset) ((parent-is "do_statement") parent-bol java-ts-mode-indent-offset) ;; ((parent-is "block") standalone-parent java-ts-mode-indent-offset) c-ts-common-baseline-indent-rule)) "Tree-sitter indent rules.") (defvar java-ts-mode--keywords '("abstract" "assert" "break" "case" "catch" "class" "continue" "default" "do" "else" "enum" "exports" "extends" "final" "finally" "for" "if" "implements" "import" "instanceof" "interface" "long" "module" "native" "new" "non-sealed" "open" "opens" "package" "permits" "private" "protected" "provides" "public" "record" "requires" "return" "sealed" "short" "static" "strictfp" "switch" "synchronized" "throw" "throws" "to" "transient" "transitive" "try" "uses" "volatile" "when" "while" "with" "yield") "Java keywords for tree-sitter font-locking.") (defvar java-ts-mode--operators '("+" ":" "++" "-" "--" "&" "&&" "|" "||" "=" "!=" "==" "*" "/" "%" "<" "<=" ">" ">=" "-=" "+=" "*=" "/=" "%=" "->" "^" "^=" "|=" "~" ">>" ">>>" "<<" "::" "?" "&=") "Java operators for tree-sitter font-locking.") (defun java-ts-mode--string-highlight-helper () "Return, for strings, a query based on what is supported by the available version of Tree-sitter for Java." (condition-case nil (progn (treesit-query-capture 'java '((text_block) @font-lock-string-face)) `((string_literal) @font-lock-string-face (text_block) @font-lock-string-face)) (error `((string_literal) @font-lock-string-face)))) (defun java-ts-mode--fontify-constant (node override start end &rest _) "Fontify a Java constant. In Java the names of variables declared class constants and of ANSI constants should be all uppercase with words separated by underscores. This function also prevents annotations from being highlighted as if they were constants. For NODE, OVERRIDE, START, and END, see `treesit-font-lock-rules'." (let ((node-start (treesit-node-start node)) (case-fold-search nil)) (when (and (not (equal (char-before node-start) ?@)) ;; skip annotations (string-match "\\`[A-Z_][0-9A-Z_]*\\'" (treesit-node-text node))) (treesit-fontify-with-override node-start (treesit-node-end node) 'font-lock-constant-face override start end)))) (defvar java-ts-mode--font-lock-settings (treesit-font-lock-rules :language 'java :override t :feature 'comment `((line_comment) @font-lock-comment-face (block_comment) @font-lock-comment-face) :language 'java :override t :feature 'keyword `([,@java-ts-mode--keywords (this) (super)] @font-lock-keyword-face (labeled_statement (identifier) @font-lock-keyword-face)) :language 'java :override t :feature 'operator `([,@java-ts-mode--operators] @font-lock-operator-face "@" @font-lock-constant-face) :language 'java :override t :feature 'annotation `((annotation name: (identifier) @font-lock-constant-face) (marker_annotation name: (identifier) @font-lock-constant-face)) :language 'java :override t :feature 'string (java-ts-mode--string-highlight-helper) :language 'java :override t :feature 'literal `((null_literal) @font-lock-constant-face (binary_integer_literal) @font-lock-number-face (decimal_integer_literal) @font-lock-number-face (hex_integer_literal) @font-lock-number-face (octal_integer_literal) @font-lock-number-face (decimal_floating_point_literal) @font-lock-number-face (hex_floating_point_literal) @font-lock-number-face) :language 'java :override t :feature 'type '((annotation_type_declaration name: (identifier) @font-lock-type-face) (interface_declaration name: (identifier) @font-lock-type-face) (class_declaration name: (identifier) @font-lock-type-face) (record_declaration name: (identifier) @font-lock-type-face) (enum_declaration name: (identifier) @font-lock-type-face) (constructor_declaration name: (identifier) @font-lock-type-face) (compact_constructor_declaration name: (identifier) @font-lock-type-face) (field_access object: (identifier) @font-lock-type-face) (method_reference (identifier) @font-lock-type-face) (scoped_identifier (identifier) @font-lock-constant-face) ((scoped_identifier name: (identifier) @font-lock-type-face) (:match "\\`[A-Z]" @font-lock-type-face)) (type_identifier) @font-lock-type-face [(boolean_type) (integral_type) (floating_point_type) (void_type)] @font-lock-type-face) :language 'java :override t :feature 'definition `((annotation_type_element_declaration name: (identifier) @font-lock-function-name-face) (method_declaration name: (identifier) @font-lock-function-name-face) (variable_declarator name: (identifier) @font-lock-variable-name-face) (element_value_pair key: (identifier) @font-lock-property-use-face) (formal_parameter name: (identifier) @font-lock-variable-name-face) (catch_formal_parameter name: (identifier) @font-lock-variable-name-face)) :language 'java :override t :feature 'expression '((method_invocation object: (identifier) @font-lock-variable-use-face) (method_invocation name: (identifier) @font-lock-function-call-face) (argument_list (identifier) @font-lock-variable-name-face) (expression_statement (identifier) @font-lock-variable-use-face)) ;; Make sure the constant feature is after expression and definition, ;; because those two applies variable-name-face on some constants. :language 'java :override t :feature 'constant `((identifier) @java-ts-mode--fontify-constant [(true) (false)] @font-lock-constant-face) :language 'java :feature 'bracket '((["(" ")" "[" "]" "{" "}"]) @font-lock-bracket-face) :language 'java :feature 'delimiter '((["," ":" ";"]) @font-lock-delimiter-face)) "Tree-sitter font-lock settings for `java-ts-mode'.") (defun java-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) ((or "method_declaration" "class_declaration" "record_declaration" "interface_declaration" "enum_declaration" "import_declaration" "package_declaration" "module_declaration") (treesit-node-text (treesit-node-child-by-field-name node "name") t)))) (defvar java-ts-mode--feature-list '(( comment document definition ) ( constant keyword string type) ( annotation expression literal) ( bracket delimiter operator))) ;;;###autoload (define-derived-mode java-ts-mode prog-mode "Java" "Major mode for editing Java, powered by tree-sitter." :group 'java :syntax-table java-ts-mode--syntax-table (unless (treesit-ensure-installed 'java) (error "Tree-sitter for Java isn't available")) (let ((primary-parser (treesit-parser-create 'java))) ;; Comments. (c-ts-common-comment-setup) ;; Indent. (setq-local c-ts-common-indent-type-regexp-alist `((block . ,(rx (or "class_body" "array_initializer" "constructor_body" "annotation_type_body" "interface_body" "lambda_expression" "enum_body" "switch_block" "record_declaration_body" "block"))) (close-bracket . "}") (if . "if_statement") (else . ("if_statement" . "alternative")) (for . "for_statement") (while . "while_statement") (do . "do_statement"))) (setq-local c-ts-common-indent-offset 'java-ts-mode-indent-offset) (setq-local treesit-simple-indent-rules java-ts-mode--indent-rules) (setq-local treesit-simple-indent-standalone-predicate #'java-ts-mode--standalone-predicate) (setq-local c-ts-common-list-indent-style 'simple) ;; Electric (setq-local electric-indent-chars (append "{}():;," electric-indent-chars)) ;; Navigation. (setq-local treesit-defun-type-regexp (regexp-opt '("method_declaration" "class_declaration" "record_declaration" "interface_declaration" "enum_declaration" "import_declaration" "package_declaration" "module_declaration" "constructor_declaration"))) (setq-local treesit-defun-name-function #'java-ts-mode--defun-name) (setq-local treesit-thing-settings `((java (sexp (not (or (and named ,(rx bos (or "program" "line_comment" "block_comment") eos)) (and anonymous ,(rx (or "{" "}" "[" "]" "(" ")" "<" ">" ",")))))) (list ,(rx bos (or "inferred_parameters" "parenthesized_expression" "argument_list" "type_arguments" "switch_block" "record_pattern_body" "block" "resource_specification" "annotation_argument_list" "element_value_array_initializer" "module_body" "enum_body" "type_parameters" "class_body" "constructor_body" "annotation_type_body" "interface_body" "array_initializer" "formal_parameters") eos)) (sentence ,(rx (or "statement" "local_variable_declaration" "field_declaration" "module_declaration" "package_declaration" "import_declaration"))) (text ,(regexp-opt '("line_comment" "block_comment" "text_block")))))) ;; Font-lock. (setq-local treesit-font-lock-settings java-ts-mode--font-lock-settings) ;; Inject doxygen parser for comment. (when (and java-ts-mode-enable-doxygen (treesit-ensure-installed 'doxygen)) (setq-local treesit-primary-parser primary-parser) (setq-local treesit-font-lock-settings (append treesit-font-lock-settings c-ts-mode-doxygen-comment-font-lock-settings)) (setq-local treesit-range-settings (treesit-range-rules :embed 'doxygen :host 'java :local t `(((block_comment) @cap (:match "/\\*\\*" @cap))))))) (setq-local treesit-font-lock-feature-list java-ts-mode--feature-list) ;; Imenu. (setq-local treesit-simple-imenu-settings '(("Class" "\\`class_declaration\\'" nil nil) ("Interface" "\\`interface_declaration\\'" nil nil) ("Enum" "\\`record_declaration\\'" nil nil) ("Method" "\\`method_declaration\\'" nil nil))) ;; Outline minor mode (setq-local treesit-outline-predicate (rx bos (or "class_declaration" "interface_declaration" "method_declaration" "constructor_declaration") eos)) (treesit-major-mode-setup)) (derived-mode-add-parents 'java-ts-mode '(java-mode)) (if (treesit-ready-p 'java) (add-to-list 'auto-mode-alist '("\\.java\\'" . java-ts-mode))) (provide 'java-ts-mode) ;;; java-ts-mode.el ends here