Documentation.

src/error.rs

@@ -1,3 +1,5 @@
+//! General error types for use in ethcore.
+
 use rustc_serialize::hex::*;
 
 #[derive(Debug)]
@@ -6,6 +8,7 @@ pub enum BaseDataError {
 }
 
 #[derive(Debug)]
+/// General error type which should be capable of representing all errors in ethcore.
 pub enum EthcoreError {
 	FromHex(FromHexError),
 	BaseData(BaseDataError),

src/hash.rs

@@ -1,3 +1,5 @@
+//! General hash types, a fixed-size raw-data type used as the output of hash functions.
+
 use std::str::FromStr;
 use std::fmt;
 use std::ops;
@@ -11,7 +13,9 @@ use bytes::BytesConvertable;
 use math::log2;
 use uint::U256;
 
-/// types implementing FixedHash must be also BytesConvertable
+/// Trait for a fixed-size byte array to be used as the output of hash functions.
+/// 
+/// Note: types implementing `FixedHash` must be also `BytesConvertable`.
 pub trait FixedHash: Sized + BytesConvertable {
 	fn new() -> Self;
 	fn random() -> Self;

src/hashdb.rs

@@ -1,7 +1,9 @@
+//! Database of byte-slices keyed to their Keccak hash.
 use hash::*;
 use bytes::*;
 use std::collections::HashMap;
 
+/// Trait modelling datastore keyed by a 32-byte Keccak hash.
 pub trait HashDB {
 	/// Get the keys in the database together with number of underlying references.
 	fn keys(&self) -> HashMap<H256, i32>;

src/trie.rs

@@ -1,3 +1,4 @@
+//! Key-value datastore with a modified Merkle tree.
 extern crate rand;
 
 use std::fmt;