X-Git-Url: http://nitlanguage.org

diff --git a/lib/standard/stream.nit b/lib/standard/stream.nit
index d26d95f..d65d377 100644
--- a/lib/standard/stream.nit
+++ b/lib/standard/stream.nit
@@ -98,6 +98,35 @@ interface OStream
 	fun is_writable: Bool is abstract
 end
 
+# Things that can be efficienlty writen to a OStream
+#
+# The point of this interface it to allow is instance to be efficenty
+# writen into a OStream without having to allocate a big String object
+#
+# ready-to-save documents usually provide this interface.
+interface Streamable
+	# Write itself to a `stream`
+	# The specific logic it let to the concrete subclasses
+	fun write_to(stream: OStream) is abstract
+
+	# Like `write_to` but return a new String (may be quite large)
+	#
+	# This funtionnality is anectodical, since the point
+	# of streamable object to to be efficienlty written to a
+	# stream without having to allocate and concatenate strings
+	fun write_to_string: String
+	do
+		var stream = new StringOStream
+		write_to(stream)
+		return stream.to_s
+	end
+end
+
+redef class String
+	super Streamable
+	redef fun write_to(stream) do stream.write(self)
+end
+
 # Input streams with a buffer
 abstract class BufferedIStream
 	super IStream