Merge: Nitgs optims

[nit.git] / lib / standard / stream.nit

diff --git a/lib/standard/stream.nit b/lib/standard/stream.nit
index d26d95f..d65d377 100644 (file)
--- 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