;;; js.el --- Major mode for editing JavaScript -*- lexical-binding: t -*-
-;; Copyright (C) 2008-2015 Free Software Foundation, Inc.
+;; Copyright (C) 2008-2016 Free Software Foundation, Inc.
;; Author: Karl Landstrom <karl.landstrom@brgeight.se>
;; Daniel Colascione <dan.colascione@gmail.com>
(require 'imenu)
(require 'moz nil t)
(require 'json nil t)
+(require 'sgml-mode)
(eval-when-compile
(require 'cl-lib)
"\\.\\(" js--name-re "\\)\\s-*?=\\s-*?\\(function\\)\\_>")
"Regexp matching an explicit JavaScript prototype \"method\" declaration.
Group 1 is a (possibly-dotted) class name, group 2 is a method name,
-and group 3 is the 'function' keyword.")
+and group 3 is the `function' keyword.")
(defconst js--plain-class-re
(concat "^\\s-*\\(" js--dotted-name-re "\\)\\.prototype"
(defun js--forward-function-decl ()
"Move forward over a JavaScript function declaration.
-This puts point at the 'function' keyword.
+This puts point at the `function' keyword.
If this is a syntactically-correct non-expression function,
return the name of the function, or t if the name could not be
determined. Otherwise, return nil."
(cl-assert (looking-at "\\_<function\\_>"))
(let ((name t))
- (forward-word)
+ (forward-word-strictly)
(forward-comment most-positive-fixnum)
(when (eq (char-after) ?*)
(forward-char)
(looking-at "\"\\s-*,\\s-*\\[")
(eq (match-end 0) (1+ list-begin)))))))
-(defun js--syntax-begin-function ()
- (when (< js--cache-end (point))
- (goto-char (max (point-min) js--cache-end)))
-
- (let ((pitem))
- (while (and (setq pitem (car (js--backward-pstate)))
- (not (eq 0 (js--pitem-paren-depth pitem)))))
-
- (when pitem
- (goto-char (js--pitem-h-begin pitem )))))
-
;;; Font Lock
(defun js--make-framework-matcher (framework &rest regexps)
"Helper function for building `js--font-lock-keywords'.
(js-syntax-propertize-regexp end))))))
(point) end))
+(defconst js--prettify-symbols-alist
+ '(("=>" . ?⇒)
+ (">=" . ?≥)
+ ("<=" . ?≤))
+ "Alist of symbol prettifications for JavaScript.")
+
;;; Indentation
(defconst js--possibly-braceless-keyword-re
"Return non-nil if point is on a JavaScript operator, other than a comma."
(save-match-data
(and (looking-at js--indent-operator-re)
- (or (not (looking-at ":"))
+ (or (not (eq (char-after) ?:))
(save-excursion
(and (js--re-search-backward "[?:{]\\|\\_<case\\_>" nil t)
- (looking-at "?")))))))
-
+ (eq (char-after) ??))))
+ (not (and
+ (eq (char-after) ?*)
+ ;; Generator method (possibly using computed property).
+ (looking-at (concat "\\* *\\(?:\\[\\|" js--name-re " *(\\)"))
+ (save-excursion
+ (js--backward-syntactic-ws)
+ ;; We might misindent some expressions that would
+ ;; return NaN anyway. Shouldn't be a problem.
+ (memq (char-before) '(?, ?} ?{))))))))
(defun js--continued-expression-p ()
"Return non-nil if the current line continues an expression."
(skip-syntax-backward " ")
(skip-syntax-backward "w_")
(looking-at js--possibly-braceless-keyword-re))
+ (memq (char-before) '(?\s ?\t ?\n ?\}))
(not (js--end-of-do-while-loop-p))))
(save-excursion
(goto-char (match-beginning 0))
(+ js-indent-level js-expr-indent-offset))
(t 0))))
+;;; JSX Indentation
+
+(defsubst js--jsx-find-before-tag ()
+ "Find where JSX starts.
+
+Assume JSX appears in the following instances:
+- Inside parentheses, when returned or as the first argument
+ to a function, and after a newline
+- When assigned to variables or object properties, but only
+ on a single line
+- As the N+1th argument to a function
+
+This is an optimized version of (re-search-backward \"[(,]\n\"
+nil t), except set point to the end of the match. This logic
+executes up to the number of lines in the file, so it should be
+really fast to reduce that impact."
+ (let (pos)
+ (while (and (> (point) (point-min))
+ (not (progn
+ (end-of-line 0)
+ (when (or (eq (char-before) 40) ; (
+ (eq (char-before) 44)) ; ,
+ (setq pos (1- (point))))))))
+ pos))
+
+(defconst js--jsx-end-tag-re
+ (concat "</" sgml-name-re ">\\|/>")
+ "Find the end of a JSX element.")
+
+(defconst js--jsx-after-tag-re "[),]"
+ "Find where JSX ends.
+This complements the assumption of where JSX appears from
+`js--jsx-before-tag-re', which see.")
+
+(defun js--jsx-indented-element-p ()
+ "Determine if/how the current line should be indented as JSX.
+
+Return `first' for the first JSXElement on its own line.
+Return `nth' for subsequent lines of the first JSXElement.
+Return `expression' for an embedded JS expression.
+Return `after' for anything after the last JSXElement.
+Return nil for non-JSX lines.
+
+Currently, JSX indentation supports the following styles:
+
+- Single-line elements (indented like normal JS):
+
+ var element = <div></div>;
+
+- Multi-line elements (enclosed in parentheses):
+
+ function () {
+ return (
+ <div>
+ <div></div>
+ </div>
+ );
+ }
+
+- Function arguments:
+
+ React.render(
+ <div></div>,
+ document.querySelector('.root')
+ );"
+ (let ((current-pos (point))
+ (current-line (line-number-at-pos))
+ last-pos
+ before-tag-pos before-tag-line
+ tag-start-pos tag-start-line
+ tag-end-pos tag-end-line
+ after-tag-line
+ parens paren type)
+ (save-excursion
+ (and
+ ;; Determine if we're inside a jsx element
+ (progn
+ (end-of-line)
+ (while (and (not tag-start-pos)
+ (setq last-pos (js--jsx-find-before-tag)))
+ (while (forward-comment 1))
+ (when (= (char-after) 60) ; <
+ (setq before-tag-pos last-pos
+ tag-start-pos (point)))
+ (goto-char last-pos))
+ tag-start-pos)
+ (progn
+ (setq before-tag-line (line-number-at-pos before-tag-pos)
+ tag-start-line (line-number-at-pos tag-start-pos))
+ (and
+ ;; A "before" line which also starts an element begins with js, so
+ ;; indent it like js
+ (> current-line before-tag-line)
+ ;; Only indent the jsx lines like jsx
+ (>= current-line tag-start-line)))
+ (cond
+ ;; Analyze bounds if there are any
+ ((progn
+ (while (and (not tag-end-pos)
+ (setq last-pos (re-search-forward js--jsx-end-tag-re nil t)))
+ (while (forward-comment 1))
+ (when (looking-at js--jsx-after-tag-re)
+ (setq tag-end-pos last-pos)))
+ tag-end-pos)
+ (setq tag-end-line (line-number-at-pos tag-end-pos)
+ after-tag-line (line-number-at-pos after-tag-line))
+ (or (and
+ ;; Ensure we're actually within the bounds of the jsx
+ (<= current-line tag-end-line)
+ ;; An "after" line which does not end an element begins with
+ ;; js, so indent it like js
+ (<= current-line after-tag-line))
+ (and
+ ;; Handle another case where there could be e.g. comments after
+ ;; the element
+ (> current-line tag-end-line)
+ (< current-line after-tag-line)
+ (setq type 'after))))
+ ;; They may not be any bounds (yet)
+ (t))
+ ;; Check if we're inside an embedded multi-line js expression
+ (cond
+ ((not type)
+ (goto-char current-pos)
+ (end-of-line)
+ (setq parens (nth 9 (syntax-ppss)))
+ (while (and parens (not type))
+ (setq paren (car parens))
+ (cond
+ ((and (>= paren tag-start-pos)
+ ;; Curly bracket indicates the start of an embedded expression
+ (= (char-after paren) 123) ; {
+ ;; The first line of the expression is indented like sgml
+ (> current-line (line-number-at-pos paren))
+ ;; Check if within a closing curly bracket (if any)
+ ;; (exclusive, as the closing bracket is indented like sgml)
+ (cond
+ ((progn
+ (goto-char paren)
+ (ignore-errors (let (forward-sexp-function)
+ (forward-sexp))))
+ (< current-line (line-number-at-pos)))
+ (t)))
+ ;; Indicate this guy will be indented specially
+ (setq type 'expression))
+ (t (setq parens (cdr parens)))))
+ t)
+ (t))
+ (cond
+ (type)
+ ;; Indent the first jsx thing like js so we can indent future jsx things
+ ;; like sgml relative to the first thing
+ ((= current-line tag-start-line) 'first)
+ ('nth))))))
+
+(defmacro js--as-sgml (&rest body)
+ "Execute BODY as if in sgml-mode."
+ `(with-syntax-table sgml-mode-syntax-table
+ (let (forward-sexp-function
+ parse-sexp-lookup-properties)
+ ,@body)))
+
+(defun js--expression-in-sgml-indent-line ()
+ "Indent the current line as JavaScript or SGML (whichever is farther)."
+ (let* (indent-col
+ (savep (point))
+ ;; Don't whine about errors/warnings when we're indenting.
+ ;; This has to be set before calling parse-partial-sexp below.
+ (inhibit-point-motion-hooks t)
+ (parse-status (save-excursion
+ (syntax-ppss (point-at-bol)))))
+ ;; Don't touch multiline strings.
+ (unless (nth 3 parse-status)
+ (setq indent-col (save-excursion
+ (back-to-indentation)
+ (if (>= (point) savep) (setq savep nil))
+ (js--as-sgml (sgml-calculate-indent))))
+ (if (null indent-col)
+ 'noindent
+ ;; Use whichever indentation column is greater, such that the sgml
+ ;; column is effectively a minimum
+ (setq indent-col (max (js--proper-indentation parse-status)
+ (+ indent-col js-indent-level)))
+ (if savep
+ (save-excursion (indent-line-to indent-col))
+ (indent-line-to indent-col))))))
+
(defun js-indent-line ()
"Indent the current line as JavaScript."
(interactive)
(indent-line-to (js--proper-indentation parse-status))
(when (> offset 0) (forward-char offset)))))
+(defun js-jsx-indent-line ()
+ "Indent the current line as JSX (with SGML offsets).
+i.e., customize JSX element indentation with `sgml-basic-offset',
+`sgml-attribute-offset' et al."
+ (interactive)
+ (let ((indentation-type (js--jsx-indented-element-p)))
+ (cond
+ ((eq indentation-type 'expression)
+ (js--expression-in-sgml-indent-line))
+ ((or (eq indentation-type 'first)
+ (eq indentation-type 'after))
+ ;; Don't treat this first thing as a continued expression (often a "<" or
+ ;; ">" causes this misinterpretation)
+ (cl-letf (((symbol-function #'js--continued-expression-p) 'ignore))
+ (js-indent-line)))
+ ((eq indentation-type 'nth)
+ (js--as-sgml (sgml-indent-line)))
+ (t (js-indent-line)))))
+
;;; Filling
(defvar js--filling-paragraph nil)
(defun js--read-tab (prompt)
"Read a Mozilla tab with prompt PROMPT.
-Return a cons of (TYPE . OBJECT). TYPE is either 'window or
-'tab, and OBJECT is a JavaScript handle to a ChromeWindow or a
+Return a cons of (TYPE . OBJECT). TYPE is either `window' or
+`tab', and OBJECT is a JavaScript handle to a ChromeWindow or a
browser, respectively."
;; Prime IDO
(setq-local open-paren-in-column-0-is-defun-start nil)
(setq-local font-lock-defaults (list js--font-lock-keywords))
(setq-local syntax-propertize-function #'js-syntax-propertize)
+ (setq-local prettify-symbols-alist js--prettify-symbols-alist)
(setq-local parse-sexp-ignore-comments t)
(setq-local parse-sexp-lookup-properties t)
(make-local-variable 'adaptive-fill-regexp)
(c-setup-paragraph-variables))
- (setq-local syntax-begin-function #'js--syntax-begin-function)
-
;; Important to fontify the whole buffer syntactically! If we don't,
;; then we might have regular expression literals that aren't marked
;; as strings, which will screw up parse-partial-sexp, scan-lists,
;;(syntax-propertize (point-max))
)
+;;;###autoload
+(define-derived-mode js-jsx-mode js-mode "JSX"
+ "Major mode for editing JSX.
+
+To customize the indentation for this mode, set the SGML offset
+variables (`sgml-basic-offset', `sgml-attribute-offset' et al.)
+locally, like so:
+
+ (defun set-jsx-indentation ()
+ (setq-local sgml-basic-offset js-indent-level))
+ (add-hook \\='js-jsx-mode-hook #\\='set-jsx-indentation)"
+ :group 'js
+ (setq-local indent-line-function #'js-jsx-indent-line))
+
;;;###autoload (defalias 'javascript-mode 'js-mode)
(eval-after-load 'folding