1 files changed, 35 insertions, 0 deletions
diff --git a/Library/Homebrew/pkg_version.rb b/Library/Homebrew/pkg_version.rb
new file mode 100644
index 000000000..3d81df261
--- /dev/null
+++ b/Library/Homebrew/pkg_version.rb
@@ -0,0 +1,35 @@
+require 'version'
+
+class PkgVersion < Version
+  attr_reader :version, :revision
+
+  RX = /\A(.+?)(?:_(\d+))?\z/
+
+  def self.parse(path)
+    _, version, revision = *path.match(RX)
+    new(version, revision)
+  end
+
+  def initialize(version, revision)
+    super(version)
+
+    if head?
+      @revision = 0
+    else
+      @revision = revision.to_i
+    end
+  end
+
+  def to_s
+    if revision > 0
+      "#{version}_#{revision}"
+    else
+      version
+    end
+  end
+  alias_method :to_str, :to_s
+
+  def <=>(other)
+    super.nonzero? || revision <=> other.revision
+  end
+end