From e3f1d70353757d5b8395c81953068c3740aff4d3 Mon Sep 17 00:00:00 2001
From: debris <marek.kotewicz@gmail.com>
Date: Fri, 15 Jan 2016 21:03:38 +0100
Subject: [PATCH] display trait implemented for rlp

---
 src/rlp/rlpin.rs         |  7 +++++++
 src/rlp/untrusted_rlp.rs | 29 +++++++++++++++++++++++++++++
 2 files changed, 36 insertions(+)

diff --git a/src/rlp/rlpin.rs b/src/rlp/rlpin.rs
index 2179643d1..4cc83b261 100644
--- a/src/rlp/rlpin.rs
+++ b/src/rlp/rlpin.rs
@@ -1,3 +1,4 @@
+use std::fmt;
 use rlp::{View, Decodable, DecoderError, UntrustedRlp, PayloadInfo, Prototype};
 
 impl<'a> From<UntrustedRlp<'a>> for Rlp<'a> {
@@ -15,6 +16,12 @@ pub struct Rlp<'a> {
 	rlp: UntrustedRlp<'a>
 }
 
+impl<'a> fmt::Display for Rlp<'a> {
+	fn fmt(&self, f: &mut fmt::Formatter) -> Result<(), fmt::Error> {
+		write!(f, "{}", self.rlp)
+	}
+}
+
 impl<'a, 'view> View<'a, 'view> for Rlp<'a> where 'a: 'view {
 	type Prototype = Prototype;
 	type PayloadInfo = PayloadInfo;
diff --git a/src/rlp/untrusted_rlp.rs b/src/rlp/untrusted_rlp.rs
index c0e7c4cf7..a5ee7990e 100644
--- a/src/rlp/untrusted_rlp.rs
+++ b/src/rlp/untrusted_rlp.rs
@@ -1,4 +1,6 @@
 use std::cell::Cell;
+use std::fmt;
+use rustc_serialize::hex::ToHex;
 use bytes::{FromBytes};
 use rlp::{View, Decoder, Decodable, DecoderError};
 
@@ -63,6 +65,24 @@ impl<'a> Clone for UntrustedRlp<'a> {
 	}
 }
 
+impl<'a> fmt::Display for UntrustedRlp<'a> {
+	fn fmt(&self, f: &mut fmt::Formatter) -> Result<(), fmt::Error> {
+		match self.prototype() {
+			Ok(Prototype::Null) => write!(f, "null"),
+			Ok(Prototype::Data(_)) => write!(f, "\"0x{}\"", self.data().unwrap().to_hex()),
+			Ok(Prototype::List(len)) => {
+				try!(write!(f, "["));
+				for i in 0..len-1 {
+					try!(write!(f, "{}, ", self.at(i).unwrap()));
+				}
+				try!(write!(f, "{}", self.at(len - 1).unwrap()));
+				write!(f, "]")
+			},
+			Err(err) => write!(f, "{:?}", err)
+		}
+	}
+}
+
 impl<'a, 'view> View<'a, 'view> for UntrustedRlp<'a> where 'a: 'view {
 	type Prototype = Result<Prototype, DecoderError>;
 	type PayloadInfo = Result<PayloadInfo, DecoderError>;
@@ -410,3 +430,12 @@ impl_array_decodable_recursive!(
 	16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31,
 	32, 40, 48, 56, 64, 72, 96, 128, 160, 192, 224,
 );
+
+#[test]
+fn test_rlp_display() {
+	use rustc_serialize::hex::FromHex;
+	let data = "f84d0589010efbef67941f79b2a056e81f171bcc55a6ff8345e692c0f86e5b48e01b996cadc001622fb5e363b421a0c5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470".from_hex().unwrap();
+	let rlp = UntrustedRlp::new(&data);
+	println!("{}", rlp);
+}
+