Make inf-clojure-repl-flavor a local variable

This patch also improves the defcustom and throws a user-error in case
the flavor is not supported.

Author: arichiardi

inf-clojure.el

@@ -222,20 +222,26 @@ whichever process buffer you want to use.")
 
 (put 'inf-clojure-mode 'mode-class 'special)
 
-(defcustom inf-clojure-repl-flavor 'clojure
-  "Symbol to define your REPL flavor.
-The default flavor is 'clojure, 'lumo is the other supported
+(defcustom inf-clojure-repl-default-flavor 'clojure
+  "Symbol to define your default REPL flavor.
+The default flavor is clojure, lumo is the other supported
 one."
-  :type 'symbol
-  :options '(clojure lumo)
+  :type '(choice (const :tag "Lumo" lumo)
+                 (other :tag "Clojure" clojure))
   :group 'inf-clojure)
 
+(defvar-local inf-clojure-repl-flavor inf-clojure-repl-default-flavor
+  "Symbol to define your REPL flavor.
+Takes its root binding from inf-clojure-repl-default-flavor but
+can be further customized using either `setq-local` or an entry
+in `.dir-locals.el`." )
+
 (defun inf-clojure--flavor-setup ()
   "Setup inf-clojure defcustoms depending on the choose flavor."
   (pcase inf-clojure-repl-flavor
-    (lumo (progn (message "[inf-clojure] will switch to the Lumo flavor")
-                 (inf-clojure--flavor-lumo-setup)))
-    (_ (message "[inf-clojure] will default to the Clojure flavor"))))
+    (lumo (inf-clojure--flavor-lumo-setup))
+    (clojure nil)
+    (_ (user-error "[inf-clojure] The specified flavor is not supported at the moment."))))
 
 (define-derived-mode inf-clojure-mode comint-mode "Inferior Clojure"
   "Major mode for interacting with an inferior Clojure process.