Add support for parinfer-rust-mode (#1)

This commit adds support for the module flag +rust, which will use parinfer-rust-mode
instead of parinfer-mode. Parinfer-rust-mode makes use of an external library named parinfer-rust
to do the heavy lifting. As such, --with-modules must be enabled.

modules/editor/parinfer/README.org

@@ -17,7 +17,9 @@ https://raw.githubusercontent.com/DogLooksGood/parinfer-mode/a7c041454e05ec2b883
 More information can be found about it [[https://shaunlebron.github.io/parinfer/][in the project's documentation]].
 
 ** Module Flags
-This module provides no flags.
++ =+rust= Use [[github:justinbarclay/parinfer-rust-mode][parinfer-rust-mode]] instead of the now deprecated [[github:DogLooksGood/parinfer-mode][parinfer-mode]].
+  This depends on Emacs being compiled with the option `--with-modules`. The
+  pre-built library is only available for Linux, Windows and MacOS.
 
 ** Packages
 + [[https://github.com/DogLooksGood/parinfer-mode][parinfer]]

modules/editor/parinfer/config.el

@@ -1,5 +1,6 @@
 ;;; editor/parinfer/config.el -*- lexical-binding: t; -*-
 
+(if (not (featurep! +rust))
     (use-package! parinfer
       :hook ((emacs-lisp-mode
               clojure-mode
@@ -22,3 +23,26 @@
             :i "<backtab>" #'parinfer-smart-tab:dwim-left
             :localleader
             :desc "Toggle parinfer-mode" "m" #'parinfer-toggle-mode))
+  (defvar parinfer-rust--doom-lib-name (cond ((eq system-type 'darwin)
+                                              "parinfer-rust-darwin.so")
+                                             ((eq system-type 'gnu/linux)
+                                              "parinfer-rust-linux.so")
+                                             ((eq system-type 'windows-nt)
+                                              "parinfer-rust-windows.dll")))
+  (use-package! parinfer-rust-mode
+    :hook ((emacs-lisp-mode
+            clojure-mode
+            scheme-mode
+            lisp-mode
+            racket-mode
+            hy-mode) . parinfer-rust-mode)
+    :init
+    (setq! parinfer-rust-library (concat user-emacs-directory
+                                         ".local/etc/parinfer-rust/"
+                                         parinfer-rust--doom-lib-name))
+    :config
+    (map! :map parinfer-rust-mode-map
+          :localleader
+          :desc "Switch parinfer-rust-mode" "m" #'parinfer-rust-switch-mode
+          :desc "Temporarily disable parinfer-rust-mode" "M"
+                #'parinfer-rust-switch-mode)))

modules/editor/parinfer/packages.el

@@ -1,7 +1,7 @@
 ;; -*- no-byte-compile: t; -*-
 ;;; editor/parinfer/packages.el
 
-(when (featurep! :editor evil)
+(when (and (not (featurep! +rust)) (featurep! :editor evil))
   ;; Parinfer uses `evil-define-key' without loading evil, so if evil is
   ;; installed *after* parinfer, parinfer will throw up void-function errors.
   ;; because evil-define-key (a macro) wasn't expanded at compile-time. So we
@@ -11,4 +11,6 @@
   ;; separate session:
   (autoload 'evil-define-key "evil-core" nil nil 'macro))
 
-(package! parinfer :pin "8659c99a9475ee34af683fdf8f272728c6bebb3a")
+(if (featurep! +rust)
+    (package! parinfer-rust-mode :pin "c825606e6aca4a2ed18c0af321df5f36a3c8c774")
+  (package! parinfer :pin "8659c99a9475ee34af683fdf8f272728c6bebb3a"))