Error handling, extra fields, and error handling for IDL deserialization

lib/serde_idl/README.adoc

@@ -1,41 +1,43 @@
 = IDL Serialization library in Rust
 
 == Using the library
-* Serialization
+* Example
 [source,rust]
-#[macro_use]
 extern crate serde_idl;
-Encode!(&42, &Some(42), &[1,2,3])
-// Encode! macro expands to:
-IDLBuilder::new().arg(&42).arg(&Some(42)).arg(&[1,2,3]).to_vec().unwrap(),
+use serde_idl::{IDLType, Deserialize, Encode, Decode};
+// Serialization
+let bytes = Encode!(&[(42, "text")], &(42, "text"));
+// Deserialization
+Decode!(&bytes, a: Vec<(i64, &str)>, b: (i32, String));
+assert_eq!(a, [(42, "text")]);
+assert_eq!(b, (42i32, "text".to_string()));
 
+* Serialize/Deserialize struct/enum
+[source,rust]
+#[derive(IDLType, Deserialize)]
+struct List {
+    head: i32,
+    tail: Option<Box<List>>,
+}
+let list = List { head: 42, tail: None };
+let bytes = Encode!(&list);
+Decode!(&bytes, l: List);
 
-* Derive serialization trait and inspect IDL type
+* Inspect IDL type
 [source,rust]
 #[derive(IDLType)]
 struct List { head: i32, tail: Option<Box<List>> }
-let list = List { head: 42, tail: None };
-assert_eq!(serde_idl::get_type(&list),
+assert_eq!(List::ty(),
            Type::Record(vec![
                field("head", Type::Int),
                field("tail", Type::Opt(Box::new(
                    Type::Knot(TypeId::of::<List>()))))])               
 );
-assert_eq!(Encode!(&list),
-           hex::decode("4449444c026c02a0d2aca8047c90eddae704016e00002a00").unwrap());
 
-* Deserialization
-[source,rust]
-let bytes = Encode!(&[(42, "text")], &(42, "text"));
-assert_eq!(bytes, hex::decode("4449444c026d016c02007c0171020001012a04746578742a0474657874").unwrap());
-Decode!(&bytes, a: Vec<(i64, &str)>, b: (i64, &str));
-assert_eq!(a, [(42, "text")]);
-assert_eq!(b, (42, "text"));
 
 == Remaining items
-* Error handling
-# Limit recursion depth for deserialization
-* Ignore extra fields, future values (subtype)
+* Limit recursion depth for deserialization
+* Support future values
 * Optimize for `new struct` type
 * Refactor serialization to use serde
 * Import `.did` file in Rust