From 9216930082ecf0592ccb99cf27d146eeea0768f2 Mon Sep 17 00:00:00 2001
From: larstvei <larstvei@ifi.uio.no>
Date: Fri, 14 Nov 2014 00:21:29 +0100
Subject: [PATCH] Working prototype.

---
 try.el | 39 ++++++++++++++-------------------------
 1 file changed, 14 insertions(+), 25 deletions(-)

diff --git a/try.el b/try.el
index 642ab87..5a80b8d 100644
--- a/try.el
+++ b/try.el
@@ -4,18 +4,8 @@
 
 (defvar try-tmp-dir "/tmp/")
 
-(defun try-newest-package-installed-p (package)
-  "Return true if the newest available PACKAGE is installed."
-  (when (package-installed-p package)
-    (let* ((local-pkg-desc (or (assq package package-alist)
-                               (assq package package--builtins)))
-           (newest-pkg-desc (assq package package-archive-contents)))
-      (and local-pkg-desc newest-pkg-desc
-           (version-list-= (package-desc-vers (cdr local-pkg-desc))
-                           (package-desc-vers (cdr newest-pkg-desc)))))))
-
-
 (defun try-raw-link-p (url)
+  "Returns non-nil if this looks like an URL to a .el file."
   (string-match-p "[^:]*://\\([^?\r\n]+\\).*\.el?$" url))
 
 (defun try-raw-link (url)
@@ -23,32 +13,31 @@
     (condition-case nil
         (progn
           (eval-region (search-forward-regexp "^$") (point-max))
-          (message "Trying!"))
+          (let ((str (car (last (split-string url "/")))))
+            (message "Trying %s!" str)))
       ((debug error)
        (message "Could not parse %s" url) nil))))
 
 (defun try-compose (f g)
+  "Compose two functions."
   (lambda (&rest x) (funcall f (apply g x))))
 
-(defun try-package (package)
-  (unless package--initialized
-    (package-initialize t))
-  (unless package-archive-contents
-    (package-refresh-contents))
-  (if (try-newest-package-installed-p package)
-      (message "Already installed.")
-    (message "Trying %s!" (symbol-name package))
-    t))
-
 (defun try ()
-  "Takes an URL to a .el-file, and evaluates it."
+  "Try out a package from your `package-archives' or pass a URL
+to a raw .el file. Packages are stored in `try-tmp-dir' and raw
+.el files are not stored at all."
   (interactive)
   (let ((url-or-package (completing-read
                          "url or package: "
                          (mapcar (try-compose 'symbol-name 'car)
                                  package-archive-contents))))
     (cond ((try-raw-link-p url-or-package) (try-raw-link url-or-package))
-          ((try-package (intern url-or-package)))
-          (t (message "Couldn't find a sensible way to try this.")))))
+          ((assq (intern url-or-package) package-archive-contents)
+           (let ((package-user-dir try-tmp-dir)
+                 (package-alist nil))
+             (package-install (intern url-or-package))
+             (message "Trying %s!" url-or-package)))
+          (t (message (concat "Couldn't find a sensible way to try this. "
+                              "Try running `package-refresh-contents'!"))))))
 
 (provide 'try)