Update haskell-mode to use prettify-symbols.

Now my haskell source is spectacular!

emacs/.emacs.d/emacs.org

@@ -986,13 +986,38 @@ Need to make haskell source be all pretty.
           )
         )
       (add-hook 'haskell-mode-hook 'interactive-haskell-mode)
-      (add-hook 'haskell-mode-hook 'turn-on-haskell-indent)
-      (add-hook 'haskell-mode-hook 'turn-on-haskell-simple-indent)
+      (add-hook 'haskell-mode-hook 'turn-on-haskell-indentation)
       (custom-set-variables
        '(haskell-program-name "ghci")
+       '(haskell-process-type 'cabal-repl)
        '(haskell-tags-on-save t)
        )
       (add-to-list 'completion-ignored-extensions ".hi")
+      (add-hook 'haskell-mode-hook'
+                (lambda ()
+                  (push '("()" . ?∅) prettify-symbols-alist)
+                  (push '("\\" . ?λ) prettify-symbols-alist)
+                  (push '("pi" . ?π) prettify-symbols-alist)
+                  (push '("=>" . ?⇒) prettify-symbols-alist)
+                  (push '("->" . ?→) prettify-symbols-alist)
+                  (push '("<-" . ?←) prettify-symbols-alist)
+                  (push '("<=" . ?≤) prettify-symbols-alist)
+                  (push '(">=" . ?≥) prettify-symbols-alist)
+                  (push '("==" . ?≡) prettify-symbols-alist)
+                  (push '("/=" . ?≢) prettify-symbols-alist)
+                  (push '("!!" . "‼") prettify-symbols-alist)
+                  (push '("&&" . ?∧) prettify-symbols-alist)
+                  (push '("||" . ?∨) prettify-symbols-alist)
+                  (push '("~>" . ?⇝) prettify-symbols-alist)
+                  (push '("-<" . ?↢) prettify-symbols-alist)
+                  (push '("not" . ?¬) prettify-symbols-alist)
+                  (push '("forall" . ?∀) prettify-symbols-alist)
+                  (push '("sqrt" . ?√) prettify-symbols-alist)
+                  (push '("undefined" . ?⊥) prettify-symbols-alist)
+                  (push '("sqrt" . ?√) prettify-symbols-alist)
+                  (prettify-symbols-mode)
+                  )
+                )
       )
     )
 #+END_SRC