diff --git a/src/error.rs b/src/error.rs
index 71514d045..e41bcd178 100644
--- a/src/error.rs
+++ b/src/error.rs
@@ -13,6 +13,7 @@ pub enum EthcoreError {
 	FromHex(FromHexError),
 	BaseData(BaseDataError),
 	BadSize,
+	UnknownName
 }
 
 impl From<FromHexError> for EthcoreError {
@@ -39,4 +40,4 @@ macro_rules! assimilate {
     )
 }
 assimilate!(FromHex);
-assimilate!(BaseData);*/
\ No newline at end of file
+assimilate!(BaseData);*/
diff --git a/src/lib.rs b/src/lib.rs
index 3a93bed98..a061a72cd 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -66,6 +66,7 @@ pub mod trie;
 pub mod nibbleslice;
 pub mod heapsizeof;
 pub mod squeeze;
+pub mod semantic_version;
 
 pub mod network;
 
diff --git a/src/semantic_version.rs b/src/semantic_version.rs
new file mode 100644
index 000000000..92f6ea376
--- /dev/null
+++ b/src/semantic_version.rs
@@ -0,0 +1,29 @@
+/// A version value with strict meaning. Use `to_u32` to convert to a simple integer.
+/// 
+/// # Example
+/// ```
+/// extern crate ethcore_util as util;
+/// use util::semantic_version::*;
+/// 
+/// fn main() {
+///   assert_eq!(SemanticVersion::new(1, 2, 3).as_u32(), 0x010203);
+/// }
+/// ```
+pub struct SemanticVersion {
+	/// Major version - API/feature removals & breaking changes.
+	pub major: u8,
+	/// Minor version - API/feature additions.
+	pub minor: u8,
+	/// Tiny version - bug fixes.
+	pub tiny: u8,
+}
+
+impl SemanticVersion {
+	/// Create a new object.
+	pub fn new(major: u8, minor: u8, tiny: u8) -> SemanticVersion { SemanticVersion{major: major, minor: minor, tiny: tiny} }
+
+	/// Convert to a `u32` representation.
+	pub fn as_u32(&self) -> u32 { ((self.major as u32) << 16) + ((self.minor as u32) << 8) + self.tiny as u32 }
+}
+
+// TODO: implement Eq, Comparison and Debug/Display for SemanticVersion.
diff --git a/src/trie/journal.rs b/src/trie/journal.rs
index 77efc991c..948f07a06 100644
--- a/src/trie/journal.rs
+++ b/src/trie/journal.rs
@@ -11,8 +11,11 @@ enum Operation {
 	Delete(H256),
 }
 
+/// How many insertions and removals were done in an `apply` operation.
 pub struct Score {
+	/// Number of insertions.
 	pub inserts: usize,
+	/// Number of removals.
 	pub removes: usize,
 }
 
@@ -54,6 +57,7 @@ impl Journal {
 		}
 	}
 
+	/// Apply this journal to the HashDB `db` and return the number of insertions and removals done.
 	pub fn apply(self, db: &mut HashDB) -> Score {
 		trace!("applying {:?} changes", self.0.len());
 		let mut ret = Score{inserts: 0, removes: 0};
diff --git a/src/uint.rs b/src/uint.rs
index 88ed49712..b8eccc4cc 100644
--- a/src/uint.rs
+++ b/src/uint.rs
@@ -97,6 +97,16 @@ macro_rules! construct_uint {
 				}
 			}
 
+			#[inline]
+			pub fn zero() -> $name {
+				From::from(0u64)
+			}
+			
+			#[inline]
+			pub fn one() -> $name {
+				From::from(1u64)
+			}
+
 			/// Multiplication by u32
 			fn mul_u32(self, other: u32) -> $name {
 				let $name(ref arr) = self;
@@ -125,6 +135,21 @@ macro_rules! construct_uint {
 		impl_map_from!($name, u8, u64);
 		impl_map_from!($name, u16, u64);
 		impl_map_from!($name, u32, u64);
+		impl_map_from!($name, usize, u64);
+
+		impl From<i64> for $name {
+			fn from(value: i64) -> $name {
+				match value >= 0 {
+					true => From::from(value as u64),
+					false => { panic!("Unsigned integer can't be created from negative value"); }
+				}
+			}
+		}
+
+		impl_map_from!($name, i8, i64);
+		impl_map_from!($name, i16, i64);
+		impl_map_from!($name, i32, i64);
+		impl_map_from!($name, isize, i64);
 
 		impl<'a> From<&'a [u8]> for $name {
 			fn from(bytes: &[u8]) -> $name {