Support REPL flavors and Lumo

This patch adds the `inf-clojure-repl-flavor` defcustom in order to
support different kind of configurations based on the selected flavor.
The default flavor is `'clojure`, and the other supported one is
`'lumo`.  It also adds other vars to further customize hostname, port
and classpath used in the Lumo flavor.

Author: arichiardi

inf-clojure.el

@@ -133,6 +133,7 @@ The following commands are available:
 
 \\{inf-clojure-minor-mode-map}"
   :lighter "" :keymap inf-clojure-minor-mode-map
+  (inf-clojure--flavor-setup)
   (inf-clojure-eldoc-setup)
   (make-local-variable 'completion-at-point-functions)
   (add-to-list 'completion-at-point-functions
@@ -208,6 +209,21 @@ 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
+one."
+  :type 'symbol
+  :options '(clojure lumo)
+  :group 'inf-clojure)
+
+(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"))))
+
 (define-derived-mode inf-clojure-mode comint-mode "Inferior Clojure"
   "Major mode for interacting with an inferior Clojure process.
 Runs a Clojure interpreter as a subprocess of Emacs, with Clojure I/O through an
@@ -559,6 +575,26 @@ The value is nil if it can't find one."
   "Return the name of the symbol at point, otherwise nil."
   (or (thing-at-point 'symbol) ""))
 
+(defun inf-clojure--empty-string-p (string)
+  "Return true if the string is empty or nil.  Expects STRING."
+  (or (null string)
+      (zerop (length string))))
+
+(defun inf-clojure--read-classpath (classpath-option)
+  "Read the classpath from the input CLASSPATH-OPTION."
+  (let ((classpath-file-path (concat (inf-clojure-project-root) classpath-option)))
+    (cond
+     ((and (file-exists-p classpath-file-path) (file-readable-p classpath-file-path))
+      (f-read classpath-file-path))
+     ;; TODO launch a command that returns the classpath string?
+     ((message (concat "Option \"" classpath-option "\" was not a (readable) file, the classpath will be empty."))
+      ""))))
+
+(defun inf-clojure--maybe-set-program (program)
+  "Set inf-clojure-program iff it is not a cons cell."
+  (when (nlistp inf-clojure-program)
+    (setq inf-clojure-program program)))
+
 ;;; Documentation functions: var doc and arglist.
 ;;; ======================================================================
 
@@ -770,6 +806,64 @@ Return the number of nested sexp the point was over or after."
   (setq-local eldoc-documentation-function #'inf-clojure-eldoc)
   (apply #'eldoc-add-command inf-clojure-extra-eldoc-commands))
 
-(provide 'inf-clojure)
+;;;; Lumo
+;;;; ====
+
+(defgroup lumo nil
+  "Run an external Lumo process (REPL) in an Emacs buffer."
+  :group 'inf-clojure)
 
+(defcustom inf-clojure-lumo-command "lumo"
+  "The command used to launch lumo."
+  :type 'string
+  :group 'lumo)
+
+(defcustom inf-clojure-lumo-args "-d"
+  "The command arguments used to launch lumo."
+  :type 'string
+  :group 'lumo)
+
+;; AR - TODO Alternatively you can specify a command string that will be called,
+;; which should return a string.
+(defcustom inf-clojure-lumo-classpath-generator "cp"
+  "The file used to create the classpath string.
+The classpath string has to be a \":\" separated list of dir and
+files."
+  :type 'string
+  :group 'lumo)
+
+;; AR - not used but left here because it is a possible sanity check
+(defun inf-clojure--lumo-mode-p ()
+  "Return true if the lumo is the target REPL."
+  (comint-send-string (inf-clojure-proc) "(js/global.hasOwnProperty \"$$LUMO_GLOBALS\")"))
+
+(defun inf-clojure--lumo-program ()
+  "Return inf-clojure-program for lumo."
+  (concat inf-clojure-lumo-command
+          " "
+          (when (not (inf-clojure--empty-string-p inf-clojure-lumo-classpath-generator))
+            (concat inf-clojure-lumo-args " "))
+          "-c " (inf-clojure--read-classpath inf-clojure-lumo-classpath-generator)))
+
+(defun inf-clojure--flavor-lumo-setup ()
+  "Setup defcustoms for the Lumo flavor."
+  ;; The defcustoms for the following are already ok:
+  ;;  * inf-clojure-set-ns-command
+  ;;  * inf-clojure-macroexpand-command
+  ;;  * inf-clojure-macroexpand-1-command
+  ;;
+  ;; https://github.com/anmonteiro/lumo/issues/84
+  ;; (setq inf-clojure-var-source-command "(lumo.repl/source %s)")
+  ;; https://github.com/anmonteiro/lumo/issues/87
+  ;; (setq inf-clojure-ns-vars-command "(lumo.repl/dir %s)")
+  ;; https://github.com/anmonteiro/lumo/issues/86
+  ;; (setq inf-clojure-var-apropos-command "(lumo.repl/apropos %s)")
+
+  ;; Uncomment after https://github.com/anmonteiro/lumo/pull/88
+  ;; (setq inf-clojure-arglist-command "(lumo.repl/get-arglists \"%s\")")
+  (setq inf-clojure-var-doc-command "(lumo.repl/doc %s)")
+  (setq inf-clojure-completion-command "(or (doall (map str (lumo.repl/get-completions \"%s\")) '())")
+  (inf-clojure--maybe-set-program (inf-clojure--lumo-program)))
+
+(provide 'inf-clojure)
 ;;; inf-clojure.el ends here