Merge pull request dimitri#901 from danielsz/master

el-get-cleanup function

el-get.el

@@ -890,6 +890,17 @@ itself.")
   (el-get-remove package)
   (el-get-install package))
 
+(defun el-get-cleanup (packages) 
+  "Removes packages absent from the argument list
+'packages. Useful, for example, when we 
+want to remove all packages not explicitly declared 
+in the user-init-file (.emacs)." 
+  (let* ((packages-to-keep (el-get-dependencies (mapcar 'el-get-as-symbol packages))) 
+	 (packages-to-remove (set-difference (mapcar 'el-get-as-symbol
+						     (el-get-list-package-names-with-status
+						      "installed")) packages-to-keep))) 
+    (mapc 'el-get-remove packages-to-remove)))
+
 ;;;###autoload
 (defun el-get-cd (package)
   "Open dired in the package directory."

el-get.info

@@ -423,9 +423,9 @@ File: el-get.info,  Node: Distributed Setup,  Next: Setup Customization,  Prev:
 
 When you are sharing your emacs setup between several machines (work
 and home destops, laptop, etc); it's usual to manage your `.emacs.d'
-setup in a distributed repository (such as `git'). El-Get then provide
-and easy canonical list of packages you depend on to run emacs, and
-this documentation is usable as-is.
+setup in a distributed repository (such as `git'). El-Get then provides
+an easy canonical list of packages you depend on to run emacs, and this
+documentation is usable as-is.
 
      (add-to-list 'load-path "~/.emacs.d/el-get/el-get")
      (require 'el-get)
@@ -456,6 +456,20 @@ this documentation is usable as-is.
 
      (el-get 'sync my-packages)
 
+   Please note that when you unreference a package from `my-packages',
+it remains locally installed.
+
+   Going one step further with the idea of a canonical list, el-get
+provides the command `el-get-cleanup', which will remove all packages
+absent from `my-packages'. This allows, in effect, to put under version
+control only the user init file, instead of the whole `.emacs.d'
+directory, and still enjoy a truly portable emacs configuration.
+
+   In the code example above, replace the last line with the following:
+
+     (el-get-cleanup my-packages)
+     (el-get 'sync my-packages)
+
 
 File: el-get.info,  Node: Setup Customization,  Prev: Distributed Setup,  Up: Setup
 
@@ -787,19 +801,19 @@ Node: Setup11900
 Node: Basic Setup12296
 Node: The el-get function13535
 Node: Distributed Setup14811
-Node: Setup Customization16122
-Node: User Init17268
-Node: Before and After properties17955
-Node: Initialization files19463
-Node: Recipes20116
-Node: Organizing recipes20591
-Node: Getting more recipes22106
-Node: Overriding package files22804
-Node: Authoring Recipes23187
-Node: Recipe format23618
-Node: Dependencies24287
-Node: Byte Compilation24633
-Node: Autoloads25199
-Node: Build26325
+Node: Setup Customization16705
+Node: User Init17851
+Node: Before and After properties18538
+Node: Initialization files20046
+Node: Recipes20699
+Node: Organizing recipes21174
+Node: Getting more recipes22689
+Node: Overriding package files23387
+Node: Authoring Recipes23770
+Node: Recipe format24201
+Node: Dependencies24870
+Node: Byte Compilation25216
+Node: Autoloads25782
+Node: Build26908
 
 End Tag Table

el-get.texi

@@ -421,7 +421,7 @@ list of already installed packages is considered.
 When you are sharing your emacs setup between several machines (work
 and home destops, laptop, etc); it's usual to manage your
 @code{.emacs.d} setup in a distributed repository (such as
-@code{git}). El-Get then provide and easy canonical list of packages
+@code{git}). El-Get then provides an easy canonical list of packages
 you depend on to run emacs, and this documentation is usable
 as-is.
 
@@ -456,6 +456,23 @@ as-is.
 (el-get 'sync my-packages)
 @end example
 
+Please note that when you unreference a package from
+@code{my-packages}, it remains locally installed.
+
+Going one step further with the idea of a canonical list, el-get
+provides the command @code{el-get-cleanup}, which will remove all
+packages absent from @code{my-packages}. This allows, in effect, to
+put under version control only the user init file, instead of the
+whole @code{.emacs.d} directory, and still enjoy a truly portable
+emacs configuration.
+
+In the code example above, replace the last line with the following:
+
+@example
+(el-get-cleanup my-packages)
+(el-get 'sync my-packages)
+@end example 
+
 @node Setup Customization
 @section Setup Customization