idiomatic changes to PodState (#10834)

ethcore/src/pod_account.rs

@@ -16,7 +16,6 @@
 
 //! Account system expressed in Plain Old Data.
 
-use std::fmt;
 use std::collections::BTreeMap;
 use itertools::Itertools;
 use hash::{keccak};
@@ -53,7 +52,8 @@ pub struct PodAccount {
 fn opt_bytes_to_hex<S>(opt_bytes: &Option<Bytes>, serializer: S) -> Result<S::Ok, S::Error>
 	where S: Serializer
 {
-	serializer.collect_str(&format_args!("0x{}",opt_bytes.as_ref().map_or("".to_string(), |b|b.to_hex())))
+	let readable = opt_bytes.as_ref().map(|b| b.to_hex()).unwrap_or_default();
+	serializer.collect_str(&format_args!("0x{}", readable))
 }
 
 impl PodAccount {
@@ -124,18 +124,6 @@ impl From<ethjson::spec::Account> for PodAccount {
 	}
 }
 
-impl fmt::Display for PodAccount {
-	fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-		write!(f, "(bal={}; nonce={}; code={} bytes, #{}; storage={} items)",
-			self.balance,
-			self.nonce,
-			self.code.as_ref().map_or(0, |c| c.len()),
-			self.code.as_ref().map_or_else(H256::zero, |c| keccak(c)),
-			self.storage.len(),
-		)
-	}
-}
-
 /// Determine difference between two optionally existant `Account`s. Returns None
 /// if they are the same.
 pub fn diff_pod(pre: Option<&PodAccount>, post: Option<&PodAccount>) -> Option<AccountDiff> {

ethcore/src/pod_state.rs

@@ -16,9 +16,7 @@
 
 //! State of all accounts in the system expressed in Plain Old Data.
 
-use std::fmt;
 use std::collections::BTreeMap;
-use itertools::Itertools;
 use ethereum_types::{H256, Address};
 use triehash::sec_trie_root;
 use pod_account::{self, PodAccount};
@@ -30,12 +28,6 @@ use ethjson;
 pub struct PodState(BTreeMap<Address, PodAccount>);
 
 impl PodState {
-	/// Contruct a new object from the `m`.
-	pub fn new() -> PodState { Default::default() }
-
-	/// Contruct a new object from the `m`.
-	pub fn from(m: BTreeMap<Address, PodAccount>) -> PodState { PodState(m) }
-
 	/// Get the underlying map.
 	pub fn get(&self) -> &BTreeMap<Address, PodAccount> { &self.0 }
 
@@ -65,31 +57,28 @@ impl From<ethjson::spec::State> for PodState {
 	}
 }
 
-impl fmt::Display for PodState {
-	fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-		for (add, acc) in &self.0 {
-			writeln!(f, "{} => {}", add, acc)?;
-		}
-		Ok(())
+impl From<BTreeMap<Address, PodAccount>> for PodState {
+	fn from(s: BTreeMap<Address, PodAccount>) -> Self {
+		PodState(s)
 	}
 }
 
 /// Calculate and return diff between `pre` state and `post` state.
 pub fn diff_pod(pre: &PodState, post: &PodState) -> StateDiff {
 	StateDiff {
-		raw: pre.get().keys()
-			.merge(post.get().keys())
-			.filter_map(|acc| pod_account::diff_pod(pre.get().get(acc), post.get().get(acc)).map(|d| (acc.clone(), d)))
+		raw: pre.0.keys()
+			.chain(post.0.keys())
+			.filter_map(|acc| pod_account::diff_pod(pre.0.get(acc), post.0.get(acc)).map(|d| (*acc, d)))
 			.collect()
 	}
 }
 
 #[cfg(test)]
 mod test {
 	use std::collections::BTreeMap;
-	use types::state_diff::*;
-	use types::account_diff::*;
 	use pod_account::PodAccount;
+	use types::account_diff::{AccountDiff, Diff};
+	use types::state_diff::StateDiff;
 	use super::{PodState, Address};
 
 	#[test]
@@ -102,15 +91,15 @@ mod test {
 				storage: map![],
 			}
 		]);
-		assert_eq!(super::diff_pod(&a, &PodState::new()), StateDiff { raw: map![
+		assert_eq!(super::diff_pod(&a, &PodState::default()), StateDiff { raw: map![
 			Address::from_low_u64_be(1) => AccountDiff{
 				balance: Diff::Died(69.into()),
 				nonce: Diff::Died(0.into()),
 				code: Diff::Died(vec![]),
 				storage: map![],
 			}
 		]});
-		assert_eq!(super::diff_pod(&PodState::new(), &a), StateDiff{ raw: map![
+		assert_eq!(super::diff_pod(&PodState::default(), &a), StateDiff{ raw: map![
 			Address::from_low_u64_be(1) => AccountDiff{
 				balance: Diff::Born(69.into()),
 				nonce: Diff::Born(0.into()),