Moving to Doom Emacs!

.emacs.d/modules/lang/haskell/+dante.el

@@ -0,0 +1,41 @@
+;;; lang/haskell/+dante.el -*- lexical-binding: t; -*-
+;;;###if (featurep! +dante)
+
+(use-package! dante
+  :hook (haskell-mode-local-vars . dante-mode)
+  :init
+  (setq dante-load-flags '(;; defaults:
+                           "+c"
+                           "-Wwarn=missing-home-modules"
+                           "-fno-diagnostics-show-caret"
+                           ;; necessary to make attrap-attrap useful:
+                           "-Wall"
+                           ;; necessary to make company completion useful:
+                           "-fdefer-typed-holes"
+                           "-fdefer-type-errors"))
+  :config
+  (when (featurep! :tools flycheck)
+    (flycheck-add-next-checker 'haskell-dante '(warning . haskell-hlint)))
+
+  (set-company-backend! 'dante-mode #'dante-company)
+
+  (defadvice! +haskell--restore-modified-state-a (orig-fn &rest args)
+    "Marks the buffer as falsely modified.
+Dante quietly saves the current buffer (without triggering save hooks) before
+invoking flycheck, unexpectedly leaving the buffer in an unmodified state. This
+is annoying if we depend on save hooks to do work on the buffer (like
+reformatting)."
+    :around #'dante-async-load-current-buffer
+    (let ((modified-p (buffer-modified-p)))
+      (apply orig-fn args)
+      (if modified-p (set-buffer-modified-p t))))
+
+  (when (featurep 'evil)
+    (add-hook 'dante-mode-hook #'evil-normalize-keymaps))
+  (map! :map dante-mode-map
+        :localleader
+        "t" #'dante-type-at
+        "i" #'dante-info
+        "l" #'haskell-process-load-or-reload
+        "e" #'dante-eval-block
+        "a" #'attrap-attrap))