rework +eshell/open and +eshell/at-cwd

empty C-u will always maps to choosing an instance, numerics will map
to numeric eshell instances.  This way you can still name your
instances if you really want, but instant access eshells through
numeric argument is allowed and incentivised.

Emacs/.config/emacs/elisp/eshell-additions.el

@@ -58,19 +58,6 @@ Uses tramp to figure out if we're in sudo mode or not.  "
       (eshell/cd (file-remote-p default-directory 'localname))))))
 
 ;; Additional functions
-(defun +eshell/at-cwd (&optional arg)
-  "Open an instance of eshell at the current working directory.
-
-Pass argument to `+eshell/open'."
-  (interactive "P")
-  (let ((dir (if buffer-file-name
-                 (file-name-directory buffer-file-name)
-               default-directory))
-        (buf (+eshell/open arg)))
-    (with-current-buffer buf
-      (eshell/cd dir)
-      (eshell-send-input))))
-
 (defun +eshell/--current-instances ()
   (cl-loop for buffer being the buffers
            if (with-current-buffer buffer
@@ -94,34 +81,34 @@ Pass argument to `+eshell/open'."
 (defun +eshell/open (&optional arg)
   "Open an instance of EShell, displaying it.
 
-If there exists only one instance of EShell, display it.  Otherwise, prompt with
-a list of open instances.  If user selects an instance, display that instance.
-Otherwise, create an instance with the name given.
+Numeric arguments passed into `+eshell/open' are reduced by 1 i.e. C-u 1
++eshell/open will map to the default eshell instance, C-u 2 +eshell/open
+will map to the next labelled eshell instance, etc.
 
-If `arg' is non nil, then always prompt user to select an instance."
+Any numeric or null argument is passed to the `eshell' function.
+
+Otherwise, if C-u is used, you can select an instance to spawn."
   (interactive "P")
   (cond
-   ((null arg)
-    ;; No arg => Choose a default instance
-    (let* ((candidates (+eshell/--current-instances))
-           (project-cand (assoc (project-prefixed-buffer-name "eshell") candidates #'string=))
-           (default-cand (assoc "*eshell*" candidates #'string=)))
-      (if-let ((cand (or project-cand default-cand)))
-          (switch-to-buffer (cdr cand))
-        (eshell))))
-   ((= (car arg) 4)
-    ;; Arg => Choose an instance
-    (+eshell/--choose-instance))
-   (t
-    ;; Double arg => Choose an instance then choose the directory
-    (let ((instance (+eshell/--choose-instance)))
-      (with-current-buffer instance
-        (thread-last (read-file-name "Enter directory: ")
-                     file-name-directory
-                     list
-                     eshell/cd)
-        (eshell-send-input))
-      instance))))
+   ((null arg) (eshell))
+   ((numberp arg)
+    (if (= arg 1)
+        (eshell nil)
+      (eshell (1- arg))))
+   (t (+eshell/--choose-instance))))
+
+(defun +eshell/at-cwd (&optional arg)
+  "Open an instance of eshell at the current working directory.
+
+Pass argument to `+eshell/open'."
+  (interactive "P")
+  (let ((dir (if buffer-file-name
+                 (file-name-directory buffer-file-name)
+               default-directory))
+        (buf (+eshell/open arg)))
+    (with-current-buffer buf
+      (eshell/cd dir)
+      (eshell-send-input))))
 
 (provide 'eshell-additions)
 ;;; eshell-additions.el ends here