flatten.rb in teapot-1.0.0.pre.rc1

- old
+ new

@@ -16,13 +16,19 @@
 # AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 # LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 # OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 # THE SOFTWARE.
 
+require 'digest/md5'
+
 module Teapot
 	class Environment
-		def flatten
+		def to_h
+			@values
+		end
+		
+		def to_hash
 			hash = {}
 			
 			# Flatten this chain of environments:
 			flatten_to_hash(hash)
 			
@@ -31,11 +37,46 @@
 			
 			# Evaluate all the individual environment values so that they are flat:
 			Hash[hash.map{|key, value| [key, evaluator.object_value(value)]}]
 		end
 		
+		def flatten
+			self.class.new(nil, self.to_hash)
+		end
+		
+		def defined
+			@values.select{|name,value| Define === value}
+		end
+		
+		def inspect(output = $stdout, indent = "")
+			@values.each do |(key, value)|
+				output.puts "#{indent}#{key}: #{value}"
+			end
+			
+			@parent.inspect(output, indent + "\t") if @parent
+		end
+		
+		# This should be stable within environments that produce the same results.
+		def checksum
+			digester = Digest::MD5.new
+			
+			checksum_recursively(digester)
+			
+			return digester.hexdigest
+		end
+		
 		protected
 		
+		def checksum_recursively(digester)
+			@values.each do |(key, value)|
+				digester.update(key.to_s)
+				digester.update(value.to_s)
+			end
+			
+			@parent.checksum_recursively(digester) if @parent
+		end
+		
+		# We fold in the ancestors one at a time from oldest to youngest.
 		def flatten_to_hash(hash)
 			if @parent
 				@parent.flatten_to_hash(hash)
 			end
 