From 7e29a78b05ff14dd67285327a01ed1a4c715b760 Mon Sep 17 00:00:00 2001
From: Jim Myhrberg <contact@jimeh.me>
Date: Sun, 15 Jan 2023 20:52:08 +0000
Subject: [PATCH] feat(language/rust): major improvements to Rust dev
 experience

---
 core/siren-core-env.el          |  1 +
 modules/languages/siren-rust.el | 51 +++++++++++++++++++++++++++++----
 modules/languages/siren-toml.el |  2 +-
 3 files changed, 48 insertions(+), 6 deletions(-)

diff --git a/core/siren-core-env.el b/core/siren-core-env.el
index 2dbddee..9bc5a90 100644
--- a/core/siren-core-env.el
+++ b/core/siren-core-env.el
@@ -19,6 +19,7 @@
                                     "GOPRIVATE"
                                     "GOENV_GOPATH_PREFIX"
                                     "GOENV_VERSION"
+                                    "RUST_BACKTRACE"
                                     "MallocNanoZone"))
   (exec-path-from-shell-arguments '("-l"))
   (exec-path-from-shell-check-startup-files nil)
diff --git a/modules/languages/siren-rust.el b/modules/languages/siren-rust.el
index af637fd..0520c63 100644
--- a/modules/languages/siren-rust.el
+++ b/modules/languages/siren-rust.el
@@ -30,20 +30,61 @@
   (rust-mode . siren-lsp-rust-mode-setup)
 
   :preface
-   (defun siren-lsp-rust-mode-setup ()
+  (defun siren-lsp-rust-mode-setup ()
     (lsp-format-buffer-on-save-mode t)
-    (lsp-organize-imports-on-save-mode t)
-    (lsp-deferred)))
+    (lsp)
+
+    ;; Disable semantic tokens as it typically causes an annoying delay with the
+    ;; syntax highlighting as you type. Essentially all new text is a very faded
+    ;; out grey color for the first 1-2 seconds as you type.
+    (lsp-semantic-tokens-mode -1))
+
+   ;; Fixes for eldoc, see:
+   ;; - https://github.com/emacs-lsp/lsp-mode/pull/1740
+   ;; - https://github.com/scturtle/dotfiles/blob/b7fdc06ca4ef4fd60170ac4ef57e3d1c9cf9a498/doom_emacs/.doom.d/config.el#L62-L77
+
+   ;; extract and show short signature for rust-analyzer
+   (cl-defmethod lsp-clients-extract-signature-on-hover (contents (_server-id (eql rust-analyzer)))
+     (let* ((value (if lsp-use-plists (plist-get contents :value) (gethash "value" contents)))
+            (groups (--partition-by (s-blank? it) (s-lines (s-trim value))))
+            (sig_group (if (s-equals? "```rust" (car (-third-item groups)))
+                           (-third-item groups)
+                         (car groups)))
+            (sig (--> sig_group
+                      (--drop-while (s-equals? "```rust" it) it)
+                      (--take-while (not (s-equals? "```" it)) it)
+                      (--map (s-trim it) it)
+                      (s-join " " it))))
+       (lsp--render-element (concat "```rust\n" sig "\n```"))))
+
+   ;; do not cache the shitty result from rust-analyzer
+   (advice-add #'lsp-eldoc-function :after (lambda (&rest _) (setq lsp--hover-saved-bounds nil))))
 
 (use-package cargo
-  :hook (rust-mode . cargo-minor-mode))
+  :hook (rust-mode . cargo-minor-mode)
+  :general
+  (:keymaps 'rust-mode-map
+            "C-c , a" 'cargo-process-test))
+
+(use-package cargo-transient
+  :general
+  (:keymaps 'rust-mode-map
+            "C-'" 'cargo-transient
+            "C-c C-," 'cargo-transient)
+
+  :custom
+  (cargo-transient-compilation-buffer-name-function
+   'cargo-transient-project-prefixed-buffer-name))
 
 (use-package flycheck-rust
   :after rust-mode
   :hook (flycheck-mode . flycheck-rust-setup))
 
 (use-package rust-playground
-  :defer t)
+  :defer t
+  :general
+  (:keymaps 'rust-playground-mode-map
+            "C-<return>" 'rust-playground-exec))
 
 (provide 'siren-rust)
 ;;; siren-rust.el ends here
diff --git a/modules/languages/siren-toml.el b/modules/languages/siren-toml.el
index 6b7120d..b80d71e 100644
--- a/modules/languages/siren-toml.el
+++ b/modules/languages/siren-toml.el
@@ -10,7 +10,7 @@
 
 (use-package conf-toml-mode
   :straight (:type built-in)
-  :mode "\\.toml\\'"
+  :mode "\\.toml\\'" "Cargo\\.lock\\'"
   :hook (conf-toml-mode . siren-toml-mode-setup)
 
   :preface