* lib/rake: Import Rake 0.9.2

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@32217 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

lib/rake/file_task.rb

@@ -0,0 +1,47 @@
+require 'rake/task.rb'
+require 'rake/early_time'
+
+module Rake
+  # #########################################################################
+  # A FileTask is a task that includes time based dependencies.  If any of a
+  # FileTask's prerequisites have a timestamp that is later than the file
+  # represented by this task, then the file must be rebuilt (using the
+  # supplied actions).
+  #
+  class FileTask < Task
+
+    # Is this file task needed?  Yes if it doesn't exist, or if its time stamp
+    # is out of date.
+    def needed?
+      ! File.exist?(name) || out_of_date?(timestamp)
+    end
+
+    # Time stamp for file task.
+    def timestamp
+      if File.exist?(name)
+        File.mtime(name.to_s)
+      else
+        Rake::EARLY
+      end
+    end
+
+    private
+
+    # Are there any prerequisites with a later time than the given time stamp?
+    def out_of_date?(stamp)
+      @prerequisites.any? { |n| application[n, @scope].timestamp > stamp}
+    end
+
+    # ----------------------------------------------------------------
+    # Task class methods.
+    #
+    class << self
+      # Apply the scope to the task name according to the rules for this kind
+      # of task.  File based tasks ignore the scope when creating the name.
+      def scope_name(scope, task_name)
+        task_name
+      end
+    end
+  end
+end
+