Solution to p6

I am not very happy about this solution; it is really crap

p6/move.el

@@ -0,0 +1,90 @@
+(defun stepping-away (cc line column)
+  (or (and (eq cc ?^) (= line 0))
+      (and (eq cc ?v) (= line (- map-height 1)))
+      (and (eq cc ?<) (= column 0))
+      (and (eq cc ?>) (= column (- map-width 1)))))
+
+(defun move ()
+  (interactive)
+  (insert "X")
+  (delete-forward-char 1)
+  (backward-char)
+  (cond
+   ((eq current-char ?^) ;going up
+    (previous-logical-line)
+    (when (eq (char-after) ?#)
+      (setq current-char ?>)
+      (next-logical-line)))
+   ((eq current-char ?>)
+    (forward-char)
+    (when (eq (char-after) ?#)
+      (setq current-char ?v)
+      (backward-char)))
+   ((eq current-char ?v)
+    (next-logical-line)
+    (when (eq (char-after) ?#)
+      (setq current-char ?<)
+      (previous-logical-line)))
+   ((eq current-char ?<)
+    (backward-char)
+    (when (eq (char-after) ?#)
+      (setq current-char ?^)
+      (forward-char))))
+  (insert current-char)
+  (delete-forward-char 1)
+  (backward-char))
+
+(defun walk-out-first-run ()
+  (interactive)
+  (let* ((sl (split-string (buffer-substring-no-properties (point-min) (point-max))))
+         (map-height (length sl))
+         (map-width (length (car sl))))
+    (goto-char (point-min))
+    (search-forward-regexp "[\\\\^|>|<|v]")
+    (backward-char)
+    (setq current-char (char-after))
+    ;; now the point is initialized at the guard's position
+    (setq guard-initial-position (point))
+    (while (not (stepping-away current-char (- (line-number-at-pos) 1) (current-column)))
+      (move))
+    (insert "X")
+    (delete-forward-char 1)
+    (backward-char)))
+
+(defun walk-out-p ()
+  "This returns t if we get out of the map, nil if we are stuck in a loop"
+  (interactive)
+  (let* ((sl (split-string (buffer-substring-no-properties (point-min) (point-max))))
+         (map-height (length sl))
+         (map-width (length (car sl))))
+    (goto-char (point-min))
+    (search-forward-regexp "[\\\\^|>|<|v]")
+    (backward-char)
+    (setq current-char (char-after))
+    (setq current-list ())
+    ;; now the point is initialized at the guard's position
+
+    (while (and (not (member (cons (point) current-char) current-list))
+                (not (stepping-away current-char (- (line-number-at-pos) 1) (current-column))))
+      (push (cons (point)  current-char) current-list)
+      (move))
+    (stepping-away current-char (- (line-number-at-pos) 1) (current-column))))
+
+(setq point-list (with-temp-buffer
+   (insert-file-contents "input")
+   (walk-out-first-run)
+   (goto-char (point-min))
+   (-unfold (lambda (x) (when (search-forward "X" nil t) (list (- (point) 1)))) nil)))
+; the above is the list of points that I can try to modify; we need to now implement the looping condition
+
+; now (length point-list) is the answer to the first part
+(length (-filter (lambda (x)
+            (with-temp-buffer
+              (insert-file-contents "input")
+              (goto-char x)
+              (insert "#")
+              (delete-forward-char 1)
+              (not (walk-out-p))))
+          (--remove (eq it guard-initial-position) point-list)))
+
+1711