feat(haskell): add treesit support

modules/lang/haskell/config.el

@@ -28,9 +28,6 @@
              #'haskell-collapse-mode ; support folding haskell code blocks
              #'interactive-haskell-mode)
 
-  (when (modulep! +tree-sitter)
-    (add-hook 'haskell-mode-local-vars-hook #'tree-sitter! 'append))
-
   (add-to-list 'completion-ignored-extensions ".hi")
 
   (map! :map haskell-mode-map
@@ -47,6 +44,16 @@
         "H" #'haskell-hide-toggle-all))
 
 
+;; TODO: Mirror other haskell-mode config to ts-mode
+(use-package! haskell-ts-mode
+  :when (modulep! +tree-sitter)
+  :when (fboundp 'haskell-ts-mode)
+  :defer t
+  :init
+  (set-tree-sitter! 'haskell-mode 'haskell-ts-mode
+    '((haskell :url "https://github.com/tree-sitter/tree-sitter-haskell"))))
+
+
 (use-package! lsp-haskell
   :when (modulep! +lsp)
   :defer t

modules/lang/haskell/doctor.el

@@ -5,6 +5,10 @@
              (modulep! :tools lsp))
          "This module requires (:tools lsp)")
 
+(assert! (or (not (modulep! +tree-sitter))
+             (modulep! :tools tree-sitter))
+         "This module requires (:tools tree-sitter)")
+
 (unless (executable-find "cabal")
   (warn! "Couldn't find cabal. haskell-mode may have issues."))
 

modules/lang/haskell/packages.el

@@ -2,6 +2,8 @@
 ;;; lang/haskell/packages.el
 
 (package! haskell-mode :pin "e9c356739310332afe59b10ffa2e6c3e76f124e3")
+(when (modulep! +tree-sitter)
+  (package! haskell-ts-mode :pin "b47211699944997bfb03fd88b1157dd71727bad7"))
 
 (when (and (modulep! +lsp)
            (modulep! :tools lsp -eglot))