add utility methods to the bencode objects

src/bencode/decode.rs

@@ -2,7 +2,7 @@ use std::collections::BTreeMap;
 use std::num::ParseIntError;
 use std::str::{self, Utf8Error};
 
-use bencode::Object;
+use bencode::{Bytes, Dict, List, Object};
 use buffer::Buffer;
 
 #[derive(Debug)]
@@ -46,7 +46,7 @@ fn decode_object(buf: &mut Buffer) -> DecodeResult<Object> {
                 }
                 list.push(decode_object(buf)?);
             }
-            Ok(Object::List(list))
+            Ok(List::new(list))
         }
         Some(b'd') => {
             buf.advance(1);
@@ -58,9 +58,9 @@ fn decode_object(buf: &mut Buffer) -> DecodeResult<Object> {
                 }
                 let key = _decode_bytes(buf)?;
                 let val = decode_object(buf)?;
-                dict.insert(key, val);
+                dict.insert(Bytes(key), val);
             }
-            Ok(Object::Dict(dict))
+            Ok(Dict::new(dict))
         }
         _ => Err(DecodeError),
     }
@@ -84,7 +84,7 @@ fn _decode_int(buf: &mut Buffer, term: u8) -> DecodeResult<i64> {
 }
 
 fn decode_bytes(buf: &mut Buffer) -> DecodeResult<Object> {
-    _decode_bytes(buf).map(|bytes| Object::Bytes(bytes))
+    _decode_bytes(buf).map(|bytes| Bytes::new(bytes))
 }
 
 fn _decode_bytes(buf: &mut Buffer) -> Result<Vec<u8>, DecodeError> {
@@ -116,7 +116,7 @@ fn test_int_neg() {
 fn test_bytes() {
     let mut buf = Buffer::new(b"5:hello");
 
-    assert_eq!(decode_bytes(&mut buf).unwrap(), Object::Bytes(b"hello".to_vec()));
+    assert_eq!(decode_bytes(&mut buf).unwrap(), Bytes::new(b"hello".to_vec()));
     assert_eq!(buf.pos(), 7);
 }
 
@@ -127,7 +127,7 @@ fn test_list() {
     let obj = decode_object(&mut buf).unwrap();
     let list = obj.as_list().unwrap();
 
-    assert_eq!(list, vec![Object::Int(1), Object::Int(2), Object::Int(3)]);
+    assert_eq!(list, &List(vec![Object::Int(1), Object::Int(2), Object::Int(3)]));
     assert_eq!(buf.pos(), 11);
 }
 
@@ -138,6 +138,6 @@ fn test_dict() {
     let obj = decode_object(&mut buf).unwrap();
     let dict = obj.as_dict().unwrap();
 
-    assert_eq!(dict[&b"hello"[..]], Object::Int(1337));
+    assert_eq!(dict.get_int("hello").unwrap(), 1337);
     assert_eq!(buf.pos(), 15);
 }

src/bencode/encode.rs

@@ -1,7 +1,6 @@
 use std::borrow::Borrow;
-use std::collections::BTreeMap;
 
-use bencode::Object;
+use bencode::{Dict, Object};
 
 pub fn encode<B>(obj: B) -> Vec<u8> where B: Borrow<Object> {
     let mut buff = Vec::new();
@@ -35,9 +34,9 @@ fn encode_list(buff: &mut Vec<u8>, list: &[Object]) {
     buff.push(b'e');
 }
 
-fn encode_dict(buff: &mut Vec<u8>, dict: &BTreeMap<Vec<u8>, Object>) {
+fn encode_dict(buff: &mut Vec<u8>, dict: &Dict) {
     buff.push(b'd');
-    for (key, val) in dict {
+    for (key, val) in dict.iter() {
         encode_bytes(buff, key);
         encode_object(buff, val);
     }
@@ -56,18 +55,25 @@ fn test_int_neg() {
 
 #[test]
 fn test_bytes() {
-    assert_eq!(encode(Object::Bytes(b"hello".to_vec())), b"5:hello");
+    use bencode::Bytes;
+
+    assert_eq!(encode(Bytes::new(b"hello".to_vec())), b"5:hello");
 }
 
 #[test]
 fn test_list() {
+    use bencode::List;
+
     let list = vec![Object::Int(1), Object::Int(2), Object::Int(3)];
-    assert_eq!(encode(Object::List(list)), b"li1ei2ei3ee");
+    assert_eq!(encode(List::new(list)), b"li1ei2ei3ee");
 }
 
 #[test]
 fn test_dict() {
+    use std::collections::BTreeMap;
+    use bencode::{Bytes, Dict};
+
     let mut dict = BTreeMap::new();
-    dict.insert(b"hello".to_vec(), Object::Int(1337));
-    assert_eq!(encode(Object::Dict(dict)), b"d5:helloi1337ee")
+    dict.insert(Bytes(b"hello".to_vec()), Object::Int(1337));
+    assert_eq!(encode(Dict::new(dict)), b"d5:helloi1337ee")
 }

src/bencode/mod.rs

@@ -1,46 +1,56 @@
 mod decode;
 mod encode;
 
+use std::borrow::Cow;
 use std::collections::BTreeMap;
 use std::fmt;
+use std::ops::{Deref, DerefMut};
 use std::str;
 
 pub use self::decode::{decode, DecodeError, DecodeResult};
 pub use self::encode::encode;
 
-#[derive(Eq, PartialEq)]
+#[derive(Clone, Eq, PartialEq)]
 pub enum Object {
     Int(i64),
-    Bytes(Vec<u8>),
-    List(Vec<Object>),
-    Dict(BTreeMap<Vec<u8>, Object>),
+    Bytes(Bytes),
+    List(List),
+    Dict(Dict),
 }
 
 impl Object {
-    pub fn as_int(self) -> Option<i64> {
-        match self {
+    pub fn as_int(&self) -> Option<i64> {
+        match *self {
             Object::Int(num) => Some(num),
             _ => None,
         }
     }
 
-    pub fn as_bytes(self) -> Option<Vec<u8>> {
-        match self {
-            Object::Bytes(bytes) => Some(bytes),
+    pub fn as_bytes(&self) -> Option<&Bytes> {
+        match *self {
+            Object::Bytes(ref bytes) => Some(bytes),
             _ => None,
         }
     }
 
-    pub fn as_list(self) -> Option<Vec<Object>> {
-        match self {
-            Object::List(list) => Some(list),
+    pub fn as_str(&self) -> Option<&str> {
+        self.as_bytes().and_then(|b| str::from_utf8(b).ok())
+    }
+
+    pub fn as_string(&self) -> Option<String> {
+        self.as_str().map(|s| s.to_string())
+    }
+
+    pub fn as_list(&self) -> Option<&List> {
+        match *self {
+            Object::List(ref list) => Some(list),
             _ => None,
         }
     }
 
-    pub fn as_dict(self) -> Option<BTreeMap<Vec<u8>, Object>> {
-        match self {
-            Object::Dict(dict) => Some(dict),
+    pub fn as_dict(&self) -> Option<&Dict> {
+        match *self {
+            Object::Dict(ref dict) => Some(dict),
             _ => None,
         }
     }
@@ -66,9 +76,136 @@ impl fmt::Debug for Object {
             }
             Object::Dict(ref dict) => {
                 f.debug_map()
-                 .entries(dict.iter().map(|(k, v)| (Object::Bytes(k.clone()), v)))
+                 .entries(dict.iter().map(|(k, v)| (k.clone(), v)))
                  .finish()
             }
         }
     }
 }
+
+#[derive(Clone, Debug, Eq, Ord, PartialEq, PartialOrd)]
+pub struct Bytes(Vec<u8>);
+
+impl Bytes {
+    pub fn new(bytes: Vec<u8>) -> Object {
+        Object::Bytes(Bytes(bytes))
+    }
+
+    pub fn str(&self) -> Option<&str> {
+        str::from_utf8(&self.0).ok()
+    }
+
+    pub fn string(&self) -> Option<String> {
+        self.str().map(|s| s.to_string())
+    }
+}
+
+impl Deref for Bytes {
+    type Target = Vec<u8>;
+
+    fn deref(&self) -> &Vec<u8> {
+        &self.0
+    }
+}
+
+impl DerefMut for Bytes {
+    fn deref_mut(&mut self) -> &mut Vec<u8> {
+        &mut self.0
+    }
+}
+
+pub trait AsBytes {
+    fn as_bytes(&self) -> Cow<Bytes>;
+}
+
+impl AsBytes for Bytes {
+    fn as_bytes(&self) -> Cow<Bytes> {
+        Cow::Borrowed(self)
+    }
+}
+
+impl<'a> AsBytes for &'a str {
+    fn as_bytes(&self) -> Cow<Bytes> {
+        Cow::Owned(Bytes(str::as_bytes(self).to_vec()))
+    }
+}
+
+impl<'a> AsBytes for &'a [u8] {
+    fn as_bytes(&self) -> Cow<Bytes> {
+        Cow::Owned(Bytes(self.to_vec()))
+    }
+}
+
+#[derive(Clone, Debug, Eq, PartialEq)]
+pub struct List(Vec<Object>);
+
+impl List {
+    pub fn new(list: Vec<Object>) -> Object {
+        Object::List(List(list))
+    }
+}
+
+impl Deref for List {
+    type Target = Vec<Object>;
+
+    fn deref(&self) -> &Vec<Object> {
+        &self.0
+    }
+}
+
+impl DerefMut for List {
+    fn deref_mut(&mut self) -> &mut Vec<Object> {
+        &mut self.0
+    }
+}
+
+#[derive(Clone, Debug, Eq, PartialEq)]
+pub struct Dict(BTreeMap<Bytes, Object>);
+
+impl Dict {
+    pub fn new(dict: BTreeMap<Bytes, Object>) -> Object {
+        Object::Dict(Dict(dict))
+    }
+
+    pub fn get_object<A>(&self, key: A) -> Option<&Object> where A: AsBytes {
+        self.0.get(&key.as_bytes())
+    }
+
+    pub fn get_int<A>(&self, key: A) -> Option<i64> where A: AsBytes {
+        self.0.get(&key.as_bytes()).and_then(|o| o.as_int())
+    }
+
+    pub fn get_bytes<A>(&self, key: A) -> Option<&Bytes> where A: AsBytes {
+        self.0.get(&key.as_bytes()).and_then(|o| o.as_bytes())
+    }
+
+    pub fn get_str<A>(&self, key: A) -> Option<&str> where A: AsBytes {
+        self.0.get(&key.as_bytes()).and_then(|o| o.as_bytes().and_then(|b| str::from_utf8(b).ok()))
+    }
+
+    pub fn get_string<A>(&self, key: A) -> Option<String> where A: AsBytes {
+        self.get_str(key).map(|s| s.to_string())
+    }
+
+    pub fn get_list<A>(&self, key: A) -> Option<&List> where A: AsBytes {
+        self.0.get(&key.as_bytes()).and_then(|o| o.as_list())
+    }
+
+    pub fn get_dict<A>(&self, key: A) -> Option<&Dict> where A: AsBytes {
+        self.0.get(&key.as_bytes()).and_then(|o| o.as_dict())
+    }
+}
+
+impl Deref for Dict {
+    type Target = BTreeMap<Bytes, Object>;
+
+    fn deref(&self) -> &BTreeMap<Bytes, Object> {
+        &self.0
+    }
+}
+
+impl DerefMut for Dict {
+    fn deref_mut(&mut self) -> &mut BTreeMap<Bytes, Object> {
+        &mut self.0
+    }
+}