lang/lua: improve moonscript & love2D support

- Fix moonscript-mode not highlighting/treating single-quoted strings as
  strings
- Fontify interpolated expressions in moonscript-mode strings (PR
  upstream?)
- Fix +lua-love-mode project detection
- Fix +lua/run-love-game love project root resolution

modules/lang/lua/autoload.el

@@ -1,27 +0,0 @@
-;;; lang/lua/autoload.el -*- lexical-binding: t; -*-
-
-;;;###autoload
-(defun +lua/open-repl ()
-  "Open Lua REPL."
-  (interactive)
-  (lua-start-process "lua" "lua")
-  (pop-to-buffer lua-process-buffer))
-
-;;;###autoload
-(defun +lua/run-love-game ()
-  "Run the current project with Love2D."
-  (interactive)
-  (when-let (root (+lua-love-project-root))
-    (async-shell-command
-     (format "%s %s"
-             (or (executable-find "love")
-                 (if IS-MAC "open -a love.app"))
-             (shell-quote-argument (file-name-directory root))))))
-
-;;;###autoload
-(defun +lua-love-project-root ()
-  "Returns the directory where a main.lua exists.
-
-Returns nil if 'love' executable can't be found."
-  (and (executable-find "love")
-       (locate-dominating-file buffer-file-name "main.lua")))

modules/lang/lua/autoload/lua.el

@@ -0,0 +1,38 @@
+;;; lang/lua/autoload/lua.el -*- lexical-binding: t; -*-
+
+(defun +lua-love-build-command ()
+  (when-let (root (+lua-love-project-root))
+    (format "%s %s"
+            (if (executable-find "love")
+                "love"
+              (if IS-MAC "open -a love.app"))
+            (shell-quote-argument root))))
+
+;;;###autoload
+(defun +lua/open-repl ()
+  "Open Lua REPL."
+  (interactive)
+  (lua-start-process "lua" "lua")
+  (pop-to-buffer lua-process-buffer))
+
+;;;###autoload
+(defun +lua/run-love-game ()
+  "Run the current project with Love2D."
+  (interactive)
+  (if-let (cmd (+lua-love-build-command))
+      (async-shell-command cmd)
+    (user-error "Couldn't find love project")))
+
+;;;###autoload
+(defun +lua-love-project-root ()
+  "Returns the directory where a main.lua exists.
+
+Returns nil if 'love' executable can't be found."
+  (when (executable-find "love")
+    (or (and (projectile-locate-dominating-file default-directory "main.lua")
+             (when-let (root (projectile-locate-dominating-file default-directory "src/main.lua"))
+               (expand-file-name "src" root)))
+        (and (featurep! +moonscript)
+             (projectile-locate-dominating-file default-directory "main.moon")
+             (when-let (root (projectile-locate-dominating-file default-directory "src/main.moon"))
+               (expand-file-name "src" root))))))

modules/lang/lua/autoload/moonscript.el

@@ -0,0 +1,16 @@
+;;; lang/lua/autoload/moonscript.el -*- lexical-binding: t; -*-
+;;;###if (featurep! +moonscript)
+
+;;;###autoload
+(defun +lua|moonscript-fix-single-quotes ()
+  "Single-quoted strings aren't treated as strings."
+  ;; (modify-syntax-entry ?\" "\"" moonscript-mode-syntax-table)
+  (modify-syntax-entry ?\' "\"" moonscript-mode-syntax-table))
+
+;;;###autoload
+(defun +lua|moonscript-fontify-interpolation ()
+  "Highlight interpolated expressions in moonscript strings."
+  (font-lock-add-keywords
+   nil '(("#{\\([^}]+\\)}"
+          (0 font-lock-preprocessor-face t)
+          (1 nil t)))))

modules/lang/lua/config.el

@@ -19,21 +19,28 @@
   (set-company-backend! 'lua-mode '(company-lua company-yasnippet)))
 
 
-;;;###package moonscript
-(setq-hook! 'moonscript-mode-hook moonscript-indent-offset tab-width)
+(def-package! moonscript
+  :when (featurep! +moonscript)
+  :defer t
+  :config
+  (setq-hook! 'moonscript-mode-hook
+    moonscript-indent-offset tab-width)
+  (add-hook! 'moonscript-mode-hook
+    #'(+lua|moonscript-fix-single-quotes
+       +lua|moonscript-fontify-interpolation)))
 
 
 ;;
 ;;; Frameworks
 
 (def-project-mode! +lua-love-mode
-  :modes (lua-mode markdown-mode json-mode)
-  :files (and "main.lua" "conf.lua")
+  :modes (moonscript-mode lua-mode markdown-mode json-mode)
+  :when #'+lua-love-project-root
   :on-load
   (progn
     (set-project-type! 'love2d
       :predicate #'+lua-love-project-root
-      :run #'+lua/run-love-game)
+      :run #'+lua-love-build-command)
     (map! :localleader
           :map +lua-love-mode-map
           "b" #'+lua/run-love-game)))