Add tap support to `edit` and `list`

Most notably, Cask.all returns an array of strings,
not of Cask instances. This makes things easier, as
well as faster, as there's no need to run map(&:to_s)
everywhere anymore.

self.path is a utility method which returns the path
of the cask from its title. There's something subtle
going in there:

 - If `cask_title` is fully qualified, e.g.
   "phinze-cask/alfred", it's straightforward.

 - If `cask_title` is only the name, e.g.
   "firefox-aurora", the name is matched from
   the full list (self.all) (which isn't sorted)
   and the first result is returned.

Hence, self.path with only the name is not precise.
There might be the possibility to apply heuristics
to do a better match (prefer phinze-cask, or maybe
installed casks?) but that's for another issue :-)

self.nice_listing is another utility method used
in `search` and `list`. It returns a list where
unique casks don't have a prefix, and duplicates
do. The prefix is the tap name. The list is then
sorted. For an example or two, look at the first
comment on phinze/#12.

lib/cask.rb

@@ -41,6 +41,24 @@ class Cask
       c
     }
   end
+  
+  def self.nice_listing(cask_list)
+    casks = {}
+    cask_list.each { |c|
+      repo, name = c.split "/"
+      casks[name] ||= []
+      casks[name].push repo
+    }
+    list = []
+    casks.each { |name,repos|
+      if repos.length == 1
+        list.push name
+      else
+        repos.each { |r| list.push [r,name].join "/" }
+      end
+    }
+    list.sort
+  end
 
   def self.init
     HOMEBREW_CACHE.mkpath
@@ -53,12 +71,16 @@ class Cask
   def homepage; self.class.homepage; end
 
   def self.installed
-    self.all.select(&:installed?)
+    self.all.select { |c| load(c).installed? }
+  end
+  
+  def self.path(cask_title)
+    cask_title = all.grep(/#{cask_title}$/).first unless cask_title =~ /\//
+    tapspath.join(cask_title.sub("/", "/Casks/") + ".rb") unless cask_title.nil?
   end
 
   def self.load(cask_title)
-    path = tapspath.join cask_title.sub("/", "/Casks/") 
-    require path
+    require path cask_title
     const_get(cask_title.split('/').last.split('-').map(&:capitalize).join).new
   end
 

lib/cask/cli/edit.rb

@@ -1,8 +1,8 @@
 class Cask::CLI::Edit
   def self.run(*arguments)
     cask_name, *rest = *arguments
-    cask_path = Cask.path.join("#{cask_name}.rb")
-    raise CaskUnavailableError, cask_path.basename('.rb').to_s unless cask_path.file?
+    cask_path = Cask.path(cask_name)
+    raise CaskUnavailableError, cask_name + ".rb" if cask_path.nil? || !cask_path.file?
     exec_editor cask_path
   end
 

lib/cask/cli/list.rb

@@ -1,6 +1,6 @@
 class Cask::CLI::List
   def self.run(*arguments)
-    puts Cask.installed.map(&:to_s).join("\n")
+    puts_columns Cask.nice_listing(Cask.installed)
   end
 
   def self.help

lib/cask/cli/search.rb

@@ -2,20 +2,7 @@ class Cask::CLI::Search
   def self.run(*arguments)
     search_term, *rest = *arguments
     casks = {}
-    Cask.all.grep(/#{search_term}/).each { |c|
-      repo, name = c.split "/"
-      casks[name] ||= []
-      casks[name].push repo
-    }
-    list = []
-    casks.each { |name,repos|
-      if repos.length == 1
-        list.push name
-      else
-        repos.each { |r| list.push [r,name].join "/" }
-      end
-    }
-    puts_columns list.sort.join "\n"
+    puts_columns Cask.nice_listing(Cask.all.grep(/#{search_term}/))
   end
 
   def self.help