rust/editors/emacs/rust-analyzer.el
2020-01-13 12:56:33 +01:00

280 lines
11 KiB
EmacsLisp

;;; rust-analyzer.el --- Rust analyzer emacs bindings for emacs-lsp -*- lexical-binding: t; -*-
;;; Code:
(require 'lsp)
(require 'dash)
(require 'ht)
;; This currently
;; - sets up rust-analyzer with emacs-lsp, giving
;; - code actions
;; - completion (use company-lsp for proper snippet support)
;; - imenu support
;; - on-type formatting
;; - 'hover' type information & documentation (with lsp-ui)
;; - implements source changes (for code actions etc.), except for file system changes
;; - implements joinLines (you need to bind rust-analyzer-join-lines to a key)
;; - implements selectionRanges (either bind lsp-extend-selection to a key, or use expand-region)
;; - provides rust-analyzer-inlay-hints-mode for inline type hints
;; - provides rust-analyzer-expand-macro to expand macros
;; What's missing:
;; - file system changes in apply-source-change
;; - semantic highlighting
;; - onEnter, parentModule, findMatchingBrace
;; - runnables
;; - the debugging commands (syntaxTree and analyzerStatus)
;; - more
;; Also, there's a problem with company-lsp's caching being too eager, sometimes
;; resulting in outdated completions.
(defcustom rust-analyzer-command '("ra_lsp_server")
""
:type '(repeat (string)))
(defconst rust-analyzer--notification-handlers
'(("rust-analyzer/publishDecorations" . (lambda (_w _p)))))
(defconst rust-analyzer--action-handlers
'(("rust-analyzer.applySourceChange" .
(lambda (p) (rust-analyzer--apply-source-change-command p)))))
(defun rust-analyzer--uri-filename (text-document)
(lsp--uri-to-path (gethash "uri" text-document)))
(defun rust-analyzer--goto-lsp-loc (loc)
(-let (((&hash "line" "character") loc))
(goto-line (1+ line))
(move-to-column character)))
(defun rust-analyzer--apply-text-document-edit (edit)
"Like lsp--apply-text-document-edit, but it allows nil version."
(let* ((ident (gethash "textDocument" edit))
(filename (rust-analyzer--uri-filename ident))
(version (gethash "version" ident)))
(with-current-buffer (find-file-noselect filename)
(when (or (not version) (= version (lsp--cur-file-version)))
(lsp--apply-text-edits (gethash "edits" edit))))))
(defun rust-analyzer--apply-source-change (data)
;; TODO fileSystemEdits
(seq-doseq (it (-> data (ht-get "workspaceEdit") (ht-get "documentChanges")))
(rust-analyzer--apply-text-document-edit it))
(-when-let (cursor-position (ht-get data "cursorPosition"))
(let ((filename (rust-analyzer--uri-filename (ht-get cursor-position "textDocument")))
(position (ht-get cursor-position "position")))
(find-file filename)
(rust-analyzer--goto-lsp-loc position))))
(defun rust-analyzer--apply-source-change-command (p)
(let ((data (-> p (ht-get "arguments") (lsp-seq-first))))
(rust-analyzer--apply-source-change data)))
(lsp-register-client
(make-lsp-client
:new-connection (lsp-stdio-connection (lambda () rust-analyzer-command))
:notification-handlers (ht<-alist rust-analyzer--notification-handlers)
:action-handlers (ht<-alist rust-analyzer--action-handlers)
:major-modes '(rust-mode)
:ignore-messages nil
:server-id 'rust-analyzer))
(defun rust-analyzer--initialized? ()
(when-let ((workspace (lsp-find-workspace 'rust-analyzer (buffer-file-name))))
(eq 'initialized (lsp--workspace-status workspace))))
(with-eval-after-load 'company-lsp
;; company-lsp provides a snippet handler for rust by default that adds () after function calls, which RA does better
(setq company-lsp--snippet-functions (cl-delete "rust" company-lsp--snippet-functions :key #'car :test #'equal)))
;; join lines
(defun rust-analyzer--join-lines-params ()
"Join lines params."
(list :textDocument (lsp--text-document-identifier)
:range (if (use-region-p)
(lsp--region-to-range (region-beginning) (region-end))
(lsp--region-to-range (point) (point)))))
(defun rust-analyzer-join-lines ()
(interactive)
(->
(lsp-send-request (lsp-make-request "rust-analyzer/joinLines"
(rust-analyzer--join-lines-params)))
(rust-analyzer--apply-source-change)))
;; selection ranges
(defun rust-analyzer--add-er-expansion ()
(make-variable-buffer-local 'er/try-expand-list)
(setq er/try-expand-list (append
er/try-expand-list
'(lsp-extend-selection))))
(with-eval-after-load 'expand-region
;; add the expansion for all existing rust-mode buffers. If expand-region is
;; loaded lazily, it might be loaded when the first rust buffer is opened, and
;; then it's too late for the hook for that buffer
(dolist (buf (buffer-list))
(with-current-buffer buf
(when (eq 'rust-mode major-mode)
(rust-analyzer--add-er-expansion))))
(add-hook 'rust-mode-hook 'rust-analyzer--add-er-expansion))
;; runnables
(defvar rust-analyzer--last-runnable nil)
(defun rust-analyzer--runnables-params ()
(list :textDocument (lsp--text-document-identifier)
:position (lsp--cur-position)))
(defun rust-analyzer--runnables ()
(lsp-send-request (lsp-make-request "rust-analyzer/runnables"
(rust-analyzer--runnables-params))))
(defun rust-analyzer--select-runnable ()
(lsp--completing-read
"Select runnable:"
(if rust-analyzer--last-runnable
(cons rust-analyzer--last-runnable (rust-analyzer--runnables))
(rust-analyzer--runnables))
(-lambda ((&hash "label")) label)))
(defun rust-analyzer-run (runnable)
(interactive (list (rust-analyzer--select-runnable)))
(-let (((&hash "env" "bin" "args" "label") runnable))
(compilation-start
(string-join (append (list bin) args '()) " ")
;; cargo-process-mode is nice, but try to work without it...
(if (functionp 'cargo-process-mode) 'cargo-process-mode nil)
(lambda (_) (concat "*" label "*")))
(setq rust-analyzer--last-runnable runnable)))
(defun rust-analyzer-rerun (&optional runnable)
(interactive (list (or rust-analyzer--last-runnable
(rust-analyzer--select-runnable))))
(rust-analyzer-run (or runnable rust-analyzer--last-runnable)))
;; analyzer status buffer
(define-derived-mode rust-analyzer-status-mode special-mode "Rust-Analyzer-Status"
"Mode for the rust-analyzer status buffer.")
(defvar-local rust-analyzer--status-buffer-workspace nil)
(defun rust-analyzer-status ()
"Displays status information for rust-analyzer."
(interactive)
(let* ((workspace (lsp-find-workspace 'rust-analyzer (buffer-file-name)))
(buf (get-buffer-create (concat "*rust-analyzer status " (with-lsp-workspace workspace (lsp-workspace-root)) "*"))))
(with-current-buffer buf
(rust-analyzer-status-mode)
(setq rust-analyzer--status-buffer-workspace workspace)
(rust-analyzer-status-buffer-refresh))
(pop-to-buffer buf)))
(defun rust-analyzer-status-buffer-refresh ()
(interactive)
(when rust-analyzer--status-buffer-workspace
(let ((inhibit-read-only t))
(erase-buffer)
(insert (with-lsp-workspace rust-analyzer--status-buffer-workspace
(lsp-send-request (lsp-make-request
"rust-analyzer/analyzerStatus")))))))
(defun rust-analyzer--syntax-tree-params ()
"Syntax tree params."
(list :textDocument (lsp--text-document-identifier)
:range (if (use-region-p)
(lsp--region-to-range (region-beginning) (region-end))
(lsp--region-to-range (point-min) (point-max)))))
(defun rust-analyzer-syntax-tree ()
"Displays syntax tree for current buffer."
(interactive)
(when (eq 'rust-mode major-mode)
(let* ((workspace (lsp-find-workspace 'rust-analyzer (buffer-file-name)))
(buf (get-buffer-create (concat "*rust-analyzer syntax tree " (with-lsp-workspace workspace (lsp-workspace-root)) "*"))))
(when workspace
(let ((parse-result (with-lsp-workspace workspace
(lsp-send-request (lsp-make-request
"rust-analyzer/syntaxTree"
(rust-analyzer--syntax-tree-params))))))
(with-current-buffer buf
(let ((inhibit-read-only t))
(erase-buffer)
(insert parse-result)))
(pop-to-buffer buf))))))
;; inlay hints
(defun rust-analyzer--update-inlay-hints (buffer)
(if (and (rust-analyzer--initialized?) (eq buffer (current-buffer)))
(lsp-send-request-async
(lsp-make-request "rust-analyzer/inlayHints"
(list :textDocument (lsp--text-document-identifier)))
(lambda (res)
(remove-overlays (point-min) (point-max) 'rust-analyzer--inlay-hint t)
(dolist (hint res)
(-let* (((&hash "range" "label" "kind") hint)
((beg . end) (lsp--range-to-region range))
(overlay (make-overlay beg end)))
(overlay-put overlay 'rust-analyzer--inlay-hint t)
(overlay-put overlay 'evaporate t)
(overlay-put overlay 'after-string (propertize (concat ": " label)
'font-lock-face 'font-lock-comment-face)))))
'tick))
nil)
(defvar-local rust-analyzer--inlay-hints-timer nil)
(defun rust-analyzer--inlay-hints-change-handler (&rest rest)
(when rust-analyzer--inlay-hints-timer
(cancel-timer rust-analyzer--inlay-hints-timer))
(setq rust-analyzer--inlay-hints-timer
(run-with-idle-timer 0.1 nil #'rust-analyzer--update-inlay-hints (current-buffer))))
(define-minor-mode rust-analyzer-inlay-hints-mode
"Mode for showing inlay hints."
nil nil nil
(cond
(rust-analyzer-inlay-hints-mode
(rust-analyzer--update-inlay-hints (current-buffer))
(add-hook 'lsp-after-initialize-hook #'rust-analyzer--inlay-hints-change-handler nil t)
(add-hook 'after-change-functions #'rust-analyzer--inlay-hints-change-handler nil t))
(t
(remove-overlays (point-min) (point-max) 'rust-analyzer--inlay-hint t)
(remove-hook 'lsp-after-initialize-hook #'rust-analyzer--inlay-hints-change-handler t)
(remove-hook 'after-change-functions #'rust-analyzer--inlay-hints-change-handler t))))
;; expand macros
(defun rust-analyzer-expand-macro ()
"Expands the macro call at point recursively."
(interactive)
(when (eq 'rust-mode major-mode)
(let* ((workspace (lsp-find-workspace 'rust-analyzer (buffer-file-name)))
(params (list :textDocument (lsp--text-document-identifier)
:position (lsp--cur-position))))
(when workspace
(let* ((response (with-lsp-workspace workspace
(lsp-send-request (lsp-make-request
"rust-analyzer/expandMacro"
params))))
(result (when response (ht-get response "expansion"))))
(if result
(let ((buf (get-buffer-create (concat "*rust-analyzer macro expansion " (with-lsp-workspace workspace (lsp-workspace-root)) "*"))))
(with-current-buffer buf
(let ((inhibit-read-only t))
(erase-buffer)
(insert result)
(setq buffer-read-only t)
(special-mode)))
(pop-to-buffer buf))
(message "No macro found at point, or it could not be expanded")))))))
(provide 'rust-analyzer)
;;; rust-analyzer.el ends here