;;; elixir-ts-mode.el --- Major mode for Elixir with tree-sitter support -*- lexical-binding: t; -*- ;; Copyright (C) 2022-2023 Free Software Foundation, Inc. ;; Author: Wilhelm H Kirschbaum ;; Created: November 2022 ;; Keywords: elixir 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: ;; ;; This package provides `elixir-ts-mode' which is a major mode for editing ;; Elixir files and embedded HEEx templates that uses Tree Sitter to parse ;; the language. ;; ;; This package is compatible with and was tested against the tree-sitter grammar ;; for Elixir found at https://github.com/elixir-lang/tree-sitter-elixir. ;; ;; Features ;; ;; * Indent ;; ;; `elixir-ts-mode' tries to replicate the indentation provided by ;; mix format, but will come with some minor differences. ;; ;; * IMenu ;; * Navigation ;; * Which-fun ;;; Code: (require 'treesit) (eval-when-compile (require 'rx)) (declare-function treesit-parser-create "treesit.c") (declare-function treesit-node-child "treesit.c") (declare-function treesit-node-type "treesit.c") (declare-function treesit-node-child-by-field-name "treesit.c") (declare-function treesit-parser-language "treesit.c") (declare-function treesit-parser-included-ranges "treesit.c") (declare-function treesit-parser-list "treesit.c") (declare-function treesit-node-parent "treesit.c") (declare-function treesit-node-start "treesit.c") (declare-function treesit-node-end "treesit.c") (declare-function treesit-query-compile "treesit.c") (declare-function treesit-query-capture "treesit.c") (declare-function treesit-node-eq "treesit.c") (declare-function treesit-node-prev-sibling "treesit.c") (defgroup elixir-ts nil "Major mode for editing Elixir code." :prefix "elixir-ts-" :group 'languages) (defcustom elixir-ts-indent-offset 2 "Indentation of Elixir statements." :version "30.1" :type 'integer :safe 'integerp :group 'elixir-ts) (defface elixir-ts-font-comment-doc-identifier-face '((t (:inherit font-lock-doc-face))) "Face used for @comment.doc tags in Elixir files.") (defface elixir-ts-font-comment-doc-attribute-face '((t (:inherit font-lock-doc-face))) "Face used for @comment.doc.__attribute__ tags in Elixir files.") (defface elixir-ts-font-sigil-name-face '((t (:inherit font-lock-string-face))) "Face used for @__name__ tags in Elixir files.") (defconst elixir-ts--sexp-regexp (rx bol (or "call" "stab_clause" "binary_operator" "list" "tuple" "map" "pair" "sigil" "string" "atom" "alias" "arguments" "identifier" "boolean" "quoted_content") eol)) (defconst elixir-ts--test-definition-keywords '("describe" "test")) (defconst elixir-ts--definition-keywords '("def" "defdelegate" "defexception" "defguard" "defguardp" "defimpl" "defmacro" "defmacrop" "defmodule" "defn" "defnp" "defoverridable" "defp" "defprotocol" "defstruct")) (defconst elixir-ts--definition-keywords-re (concat "^" (regexp-opt elixir-ts--definition-keywords) "$")) (defconst elixir-ts--kernel-keywords '("alias" "case" "cond" "else" "for" "if" "import" "quote" "raise" "receive" "require" "reraise" "super" "throw" "try" "unless" "unquote" "unquote_splicing" "use" "with")) (defconst elixir-ts--kernel-keywords-re (concat "^" (regexp-opt elixir-ts--kernel-keywords) "$")) (defconst elixir-ts--builtin-keywords '("__MODULE__" "__DIR__" "__ENV__" "__CALLER__" "__STACKTRACE__")) (defconst elixir-ts--builtin-keywords-re (concat "^" (regexp-opt elixir-ts--builtin-keywords) "$")) (defconst elixir-ts--doc-keywords '("moduledoc" "typedoc" "doc")) (defconst elixir-ts--doc-keywords-re (concat "^" (regexp-opt elixir-ts--doc-keywords) "$")) (defconst elixir-ts--reserved-keywords '("when" "and" "or" "not" "in" "not in" "fn" "do" "end" "catch" "rescue" "after" "else")) (defconst elixir-ts--reserved-keywords-re (concat "^" (regexp-opt elixir-ts--reserved-keywords) "$")) (defconst elixir-ts--reserved-keywords-vector (apply #'vector elixir-ts--reserved-keywords)) (defvar elixir-ts--capture-anonymous-function-end (when (treesit-available-p) (treesit-query-compile 'elixir '((anonymous_function "end" @end))))) (defvar elixir-ts--capture-operator-parent (when (treesit-available-p) (treesit-query-compile 'elixir '((binary_operator operator: _ @val))))) (defvar elixir-ts--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 ?? "w" table) (modify-syntax-entry ?~ "w" table) (modify-syntax-entry ?! "_" table) (modify-syntax-entry ?' "\"" table) (modify-syntax-entry ?\" "\"" table) (modify-syntax-entry ?# "<" table) (modify-syntax-entry ?\n ">" 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) table) "Syntax table for `elixir-ts-mode'.") (defun elixir-ts--argument-indent-offset (node _parent &rest _) "Return the argument offset position for NODE." (if (treesit-node-prev-sibling node t) 0 elixir-ts-indent-offset)) (defun elixir-ts--argument-indent-anchor (node parent &rest _) "Return the argument anchor position for NODE and PARENT." (let ((first-sibling (treesit-node-child parent 0 t))) (if (and first-sibling (not (treesit-node-eq first-sibling node))) (treesit-node-start first-sibling) (elixir-ts--parent-expression-start node parent)))) (defun elixir-ts--parent-expression-start (_node parent &rest _) "Return the indentation expression start for NODE and PARENT." ;; If the parent is the first expression on the line return the ;; parent start of node position, otherwise use the parent call ;; start if available. (if (eq (treesit-node-start parent) (save-excursion (goto-char (treesit-node-start parent)) (back-to-indentation) (point))) (treesit-node-start parent) (let ((expr-parent (treesit-parent-until parent (lambda (n) (member (treesit-node-type n) '("call" "binary_operator" "keywords" "list")))))) (save-excursion (goto-char (treesit-node-start expr-parent)) (back-to-indentation) (if (looking-at "|>") (point) (treesit-node-start expr-parent)))))) (defvar elixir-ts--indent-rules (let ((offset elixir-ts-indent-offset)) `((elixir ((parent-is "^source$") column-0 0) ((parent-is "^string$") parent-bol 0) ((parent-is "^quoted_content$") (lambda (_n parent bol &rest _) (save-excursion (back-to-indentation) (if (bolp) (progn (goto-char (treesit-node-start parent)) (back-to-indentation) (point)) (point)))) 0) ((node-is "^|>$") parent-bol 0) ((node-is "^|$") parent-bol 0) ((node-is "^]$") ,'elixir-ts--parent-expression-start 0) ((node-is "^}$") ,'elixir-ts--parent-expression-start 0) ((node-is "^)$") ,'elixir-ts--parent-expression-start 0) ((node-is "^else_block$") grand-parent 0) ((node-is "^catch_block$") grand-parent 0) ((node-is "^rescue_block$") grand-parent 0) ((node-is "^after_block$") grand-parent 0) ((parent-is "^else_block$") parent ,offset) ((parent-is "^catch_block$") parent ,offset) ((parent-is "^rescue_block$") parent ,offset) ((parent-is "^rescue_block$") parent ,offset) ((parent-is "^after_block$") parent ,offset) ((parent-is "^access_call$") ,'elixir-ts--argument-indent-anchor ,'elixir-ts--argument-indent-offset) ((parent-is "^tuple$") ,'elixir-ts--argument-indent-anchor ,'elixir-ts--argument-indent-offset) ((parent-is "^list$") ,'elixir-ts--argument-indent-anchor ,'elixir-ts--argument-indent-offset) ((parent-is "^pair$") parent ,offset) ((parent-is "^map_content$") parent-bol 0) ((parent-is "^map$") ,'elixir-ts--parent-expression-start ,offset) ((node-is "^stab_clause$") parent-bol ,offset) ((query ,elixir-ts--capture-operator-parent) grand-parent 0) ((node-is "^when$") parent 0) ((node-is "^keywords$") parent-bol ,offset) ((parent-is "^body$") (lambda (node parent _) (save-excursion ;; The grammar adds a comment outside of the body, so we have to indent ;; to the grand-parent if it is available. (goto-char (treesit-node-start (or (treesit-node-parent parent) (parent)))) (back-to-indentation) (point))) ,offset) ((parent-is "^arguments$") ,'elixir-ts--argument-indent-anchor ,'elixir-ts--argument-indent-offset) ;; Handle incomplete maps when parent is ERROR. ((n-p-gp "^binary_operator$" "ERROR" nil) parent-bol 0) ;; When there is an ERROR, just indent to prev-line. ((parent-is "ERROR") prev-line 0) ((node-is "^binary_operator$") (lambda (node parent &rest _) (let ((top-level (treesit-parent-while node (lambda (node) (equal (treesit-node-type node) "binary_operator"))))) (if (treesit-node-eq top-level node) (elixir-ts--parent-expression-start node parent) (treesit-node-start top-level)))) (lambda (node parent _) (cond ((equal (treesit-node-type parent) "do_block") ,offset) ((equal (treesit-node-type parent) "binary_operator") ,offset) (t 0)))) ((parent-is "^binary_operator$") (lambda (node parent bol &rest _) (treesit-node-start (treesit-parent-while parent (lambda (node) (equal (treesit-node-type node) "binary_operator"))))) ,offset) ((node-is "^pair$") first-sibling 0) ((query ,elixir-ts--capture-anonymous-function-end) parent-bol 0) ((node-is "^end$") standalone-parent 0) ((parent-is "^do_block$") grand-parent ,offset) ((parent-is "^anonymous_function$") elixir-ts--treesit-anchor-grand-parent-bol ,offset) ((parent-is "^else_block$") parent ,offset) ((parent-is "^rescue_block$") parent ,offset) ((parent-is "^catch_block$") parent ,offset) ((parent-is "^keywords$") parent-bol 0) ((node-is "^call$") parent-bol ,offset) ((node-is "^comment$") parent-bol ,offset))))) (defvar elixir-ts--font-lock-settings (treesit-font-lock-rules :language 'elixir :feature 'elixir-comment '((comment) @font-lock-comment-face) :language 'elixir :feature 'elixir-string :override t '([(string) (charlist)] @font-lock-string-face) :language 'elixir :feature 'elixir-string-interpolation :override t '((string [ quoted_end: _ @font-lock-string-face quoted_start: _ @font-lock-string-face (quoted_content) @font-lock-string-face (interpolation "#{" @font-lock-regexp-grouping-backslash "}" @font-lock-regexp-grouping-backslash) ]) (charlist [ quoted_end: _ @font-lock-string-face quoted_start: _ @font-lock-string-face (quoted_content) @font-lock-string-face (interpolation "#{" @font-lock-regexp-grouping-backslash "}" @font-lock-regexp-grouping-backslash) ])) :language 'elixir :feature 'elixir-keyword `(,elixir-ts--reserved-keywords-vector @font-lock-keyword-face (binary_operator operator: _ @font-lock-keyword-face (:match ,elixir-ts--reserved-keywords-re @font-lock-keyword-face))) :language 'elixir :feature 'elixir-doc :override t `((unary_operator operator: "@" @elixir-ts-font-comment-doc-attribute-face operand: (call target: (identifier) @elixir-ts-font-comment-doc-identifier-face ;; Arguments can be optional, so adding another ;; entry without arguments. ;; If we don't handle then we don't apply font ;; and the non doc fortification query will take specify ;; a more specific font which takes precedence. (arguments [ (string) @font-lock-doc-face (charlist) @font-lock-doc-face (sigil) @font-lock-doc-face (boolean) @font-lock-doc-face ])) (:match ,elixir-ts--doc-keywords-re @elixir-ts-font-comment-doc-identifier-face)) (unary_operator operator: "@" @elixir-ts-font-comment-doc-attribute-face operand: (call target: (identifier) @elixir-ts-font-comment-doc-identifier-face) (:match ,elixir-ts--doc-keywords-re @elixir-ts-font-comment-doc-identifier-face))) :language 'elixir :feature 'elixir-unary-operator `((unary_operator operator: "@" @font-lock-preprocessor-face operand: [ (identifier) @font-lock-preprocessor-face (call target: (identifier) @font-lock-preprocessor-face) (boolean) @font-lock-preprocessor-face (nil) @font-lock-preprocessor-face ]) (unary_operator operator: "&") @font-lock-function-name-face (operator_identifier) @font-lock-operator-face) :language 'elixir :feature 'elixir-operator '((binary_operator operator: _ @font-lock-operator-face) (dot operator: _ @font-lock-operator-face) (stab_clause operator: _ @font-lock-operator-face) [(boolean) (nil)] @font-lock-constant-face [(integer) (float)] @font-lock-number-face (alias) @font-lock-type-face (call target: (dot left: (atom) @font-lock-type-face)) (char) @font-lock-constant-face [(atom) (quoted_atom)] @font-lock-type-face [(keyword) (quoted_keyword)] @font-lock-builtin-face) :language 'elixir :feature 'elixir-call `((call target: (identifier) @font-lock-keyword-face (:match ,elixir-ts--definition-keywords-re @font-lock-keyword-face)) (call target: (identifier) @font-lock-keyword-face (:match ,elixir-ts--kernel-keywords-re @font-lock-keyword-face)) (call target: [(identifier) @font-lock-function-name-face (dot right: (identifier) @font-lock-keyword-face)]) (call target: (identifier) @font-lock-keyword-face (arguments [ (identifier) @font-lock-keyword-face (binary_operator left: (identifier) @font-lock-keyword-face operator: "when") ]) (:match ,elixir-ts--definition-keywords-re @font-lock-keyword-face)) (call target: (identifier) @font-lock-keyword-face (arguments (binary_operator operator: "|>" right: (identifier))) (:match ,elixir-ts--definition-keywords-re @font-lock-keyword-face))) :language 'elixir :feature 'elixir-constant `((binary_operator operator: "|>" right: (identifier) @font-lock-function-name-face) ((identifier) @font-lock-keyword-face (:match ,elixir-ts--builtin-keywords-re @font-lock-keyword-face)) ((identifier) @font-lock-comment-face (:match "^_" @font-lock-comment-face)) (identifier) @font-lock-function-name-face ["%"] @font-lock-keyward-face ["," ";"] @font-lock-keyword-face ["(" ")" "[" "]" "{" "}" "<<" ">>"] @font-lock-keyword-face) :language 'elixir :feature 'elixir-sigil :override t `((sigil (sigil_name) @elixir-ts-font-sigil-name-face quoted_start: _ @font-lock-string-face quoted_end: _ @font-lock-string-face (:match "^[sSwWpP]$" @elixir-ts-font-sigil-name-face)) @font-lock-string-face (sigil (sigil_name) @elixir-ts-font-sigil-name-face quoted_start: _ @font-lock-regex-face quoted_end: _ @font-lock-regex-face (:match "^[rR]$" @elixir-ts-font-sigil-name-face)) @font-lock-regex-face (sigil "~" @font-lock-string-face (sigil_name) @elixir-ts-font-sigil-name-face quoted_start: _ @font-lock-string-face quoted_end: _ @font-lock-string-face (:match "^[HF]$" @elixir-ts-font-sigil-name-face))) :language 'elixir :feature 'elixir-string-escape :override t `((escape_sequence) @font-lock-regexp-grouping-backslash)) "Tree-sitter font-lock settings.") (defvar elixir-ts--treesit-range-rules (when (treesit-available-p) (treesit-range-rules :embed 'heex :host 'elixir '((sigil (sigil_name) @name (:match "^[HF]$" @name) (quoted_content) @heex))))) (defvar heex-ts--sexp-regexp) (defvar heex-ts--indent-rules) (defvar heex-ts--font-lock-settings) (defun elixir-ts--forward-sexp (&optional arg) "Move forward across one balanced expression (sexp). With ARG, do it many times. Negative ARG means move backward." (or arg (setq arg 1)) (funcall (if (> arg 0) #'treesit-end-of-thing #'treesit-beginning-of-thing) (if (eq (treesit-language-at (point)) 'heex) heex-ts--sexp-regexp elixir-ts--sexp-regexp) (abs arg))) (defun elixir-ts--treesit-anchor-grand-parent-bol (_n parent &rest _) "Return the beginning of non-space characters for the parent node of PARENT." (save-excursion (goto-char (treesit-node-start (treesit-node-parent parent))) (back-to-indentation) (point))) (defun elixir-ts--treesit-language-at-point (point) "Return the language at POINT." (let* ((range nil) (language-in-range (cl-loop for parser in (treesit-parser-list) do (setq range (cl-loop for range in (treesit-parser-included-ranges parser) if (and (>= point (car range)) (<= point (cdr range))) return parser)) if range return (treesit-parser-language parser)))) (if (null language-in-range) (when-let ((parser (car (treesit-parser-list)))) (treesit-parser-language parser)) language-in-range))) (defun elixir-ts--defun-p (node) "Return non-nil when NODE is a defun." (member (treesit-node-text (treesit-node-child-by-field-name node "target")) (append elixir-ts--definition-keywords elixir-ts--test-definition-keywords))) (defun elixir-ts--defun-name (node) "Return the name of the defun NODE. Return nil if NODE is not a defun node or doesn't have a name." (pcase (treesit-node-type node) ("call" (let ((node-child (treesit-node-child (treesit-node-child node 1) 0))) (pcase (treesit-node-type node-child) ("alias" (treesit-node-text node-child t)) ("call" (treesit-node-text (treesit-node-child-by-field-name node-child "target") t)) ("binary_operator" (treesit-node-text (treesit-node-child-by-field-name (treesit-node-child-by-field-name node-child "left") "target") t)) ("identifier" (treesit-node-text node-child t)) (_ nil)))) (_ nil))) (defvar elixir-ts--syntax-propertize-query (when (treesit-available-p) (treesit-query-compile 'elixir '(((["\"\"\""] @quoted-text)))))) (defun elixir-ts--syntax-propertize (start end) "Apply syntax text properties between START and END for `elixir-ts-mode'." (let ((captures (treesit-query-capture 'elixir elixir-ts--syntax-propertize-query start end))) (pcase-dolist (`(,name . ,node) captures) (pcase-exhaustive name ('quoted-text (put-text-property (1- (treesit-node-end node)) (treesit-node-end node) 'syntax-table (string-to-syntax "$"))))))) ;;;###autoload (define-derived-mode elixir-ts-mode prog-mode "Elixir" "Major mode for editing Elixir, powered by tree-sitter." :group 'elixir-ts :syntax-table elixir-ts--syntax-table ;; Comments (setq-local comment-start "# ") (setq-local comment-start-skip (rx "#" (* (syntax whitespace)))) (setq-local comment-end "") (setq-local comment-end-skip (rx (* (syntax whitespace)) (group (or (syntax comment-end) "\n")))) ;; Compile (setq-local compile-command "mix") (when (treesit-ready-p 'elixir) ;; The HEEx parser has to be created first for elixir to ensure elixir ;; is the first language when looking for treesit ranges. (when (treesit-ready-p 'heex) ;; Require heex-ts-mode only when we load elixir-ts-mode ;; so that we don't get a tree-sitter compilation warning for ;; elixir-ts-mode. (require 'heex-ts-mode) (treesit-parser-create 'heex)) (treesit-parser-create 'elixir) (setq-local treesit-language-at-point-function 'elixir-ts--treesit-language-at-point) ;; Font-lock. (setq-local treesit-font-lock-settings elixir-ts--font-lock-settings) (setq-local treesit-font-lock-feature-list '(( elixir-comment elixir-constant elixir-doc ) ( elixir-string elixir-keyword elixir-unary-operator elixir-call elixir-operator ) ( elixir-sigil elixir-string-escape elixir-string-interpolation))) ;; Imenu. (setq-local treesit-simple-imenu-settings '((nil "\\`call\\'" elixir-ts--defun-p nil))) ;; Indent. (setq-local treesit-simple-indent-rules elixir-ts--indent-rules) ;; Navigation (setq-local forward-sexp-function #'elixir-ts--forward-sexp) (setq-local treesit-defun-type-regexp '("call" . elixir-ts--defun-p)) (setq-local treesit-defun-name-function #'elixir-ts--defun-name) ;; Embedded Heex (when (treesit-ready-p 'heex) (setq-local treesit-range-settings elixir-ts--treesit-range-rules) (setq-local treesit-simple-indent-rules (append treesit-simple-indent-rules heex-ts--indent-rules)) (setq-local treesit-font-lock-settings (append treesit-font-lock-settings heex-ts--font-lock-settings)) (setq-local treesit-simple-indent-rules (append treesit-simple-indent-rules heex-ts--indent-rules)) (setq-local treesit-font-lock-feature-list '(( elixir-comment elixir-constant elixir-doc heex-comment heex-keyword heex-doctype ) ( elixir-string elixir-keyword elixir-unary-operator elixir-call elixir-operator heex-component heex-tag heex-attribute heex-string) ( elixir-sigil elixir-string-escape elixir-string-interpolation )))) (treesit-major-mode-setup) (setq-local syntax-propertize-function #'elixir-ts--syntax-propertize))) (if (treesit-ready-p 'elixir) (progn (add-to-list 'auto-mode-alist '("\\.elixir\\'" . elixir-ts-mode)) (add-to-list 'auto-mode-alist '("\\.ex\\'" . elixir-ts-mode)) (add-to-list 'auto-mode-alist '("\\.exs\\'" . elixir-ts-mode)) (add-to-list 'auto-mode-alist '("mix\\.lock" . elixir-ts-mode)))) (provide 'elixir-ts-mode) ;;; elixir-ts-mode.el ends here