Merge pull request #150 from fjl/develop

Merge eth-go repo into go-ethereum

23 files changed, 2012 insertions, 0 deletions

diff --git a/ethutil/.gitignore b/ethutil/.gitignore
new file mode 100644
index 000000000..f725d58d1
--- /dev/null
+++ b/ethutil/.gitignore
@@ -0,0 +1,12 @@
+# See http://help.github.com/ignore-files/ for more about ignoring files.
+#
+# If you find yourself ignoring temporary files generated by your text editor
+# or operating system, you probably want to add a global ignore instead:
+#   git config --global core.excludesfile ~/.gitignore_global
+
+/tmp
+*/**/*un~
+*un~
+.DS_Store
+*/**/.DS_Store
+
diff --git a/ethutil/.travis.yml b/ethutil/.travis.yml
new file mode 100644
index 000000000..69359072d
--- /dev/null
+++ b/ethutil/.travis.yml
@@ -0,0 +1,3 @@
+language: go
+go:
+  - 1.2
diff --git a/ethutil/README.md b/ethutil/README.md
new file mode 100644
index 000000000..1ed56b71b
--- /dev/null
+++ b/ethutil/README.md
@@ -0,0 +1,139 @@
+# ethutil
+
+[![Build
+Status](https://travis-ci.org/ethereum/go-ethereum.png?branch=master)](https://travis-ci.org/ethereum/go-ethereum)
+
+The ethutil package contains the ethereum utility library.
+
+# Installation
+
+`go get github.com/ethereum/ethutil-go`
+
+# Usage
+
+## RLP (Recursive Linear Prefix) Encoding
+
+RLP Encoding is an encoding scheme utilized by the Ethereum project. It
+encodes any native value or list to string.
+
+More in depth information about the Encoding scheme see the [Wiki](http://wiki.ethereum.org/index.php/RLP)
+article.
+
+```go
+rlp := ethutil.Encode("doge")
+fmt.Printf("%q\n", rlp) // => "\0x83dog"
+
+rlp = ethutil.Encode([]interface{}{"dog", "cat"})
+fmt.Printf("%q\n", rlp) // => "\0xc8\0x83dog\0x83cat"
+decoded := ethutil.Decode(rlp)
+fmt.Println(decoded) // => ["dog" "cat"]
+```
+
+## Patricia Trie
+
+Patricie Tree is a merkle trie utilized by the Ethereum project.
+
+More in depth information about the (modified) Patricia Trie can be
+found on the [Wiki](http://wiki.ethereum.org/index.php/Patricia_Tree).
+
+The patricia trie uses a db as backend and could be anything as long as
+it satisfies the Database interface found in `ethutil/db.go`.
+
+```go
+db := NewDatabase()
+
+// db, root
+trie := ethutil.NewTrie(db, "")
+
+trie.Put("puppy", "dog")
+trie.Put("horse", "stallion")
+trie.Put("do", "verb")
+trie.Put("doge", "coin")
+
+// Look up the key "do" in the trie
+out := trie.Get("do")
+fmt.Println(out) // => verb
+
+trie.Delete("puppy")
+```
+
+The patricia trie, in combination with RLP, provides a robust,
+cryptographically authenticated data structure that can be used to store
+all (key, value) bindings.
+
+```go
+// ... Create db/trie
+
+// Note that RLP uses interface slices as list
+value := ethutil.Encode([]interface{}{"one", 2, "three", []interface{}{42}})
+// Store the RLP encoded value of the list
+trie.Put("mykey", value)
+```
+
+## Value
+
+Value is a Generic Value which is used in combination with RLP data or
+`([])interface{}` structures. It may serve as a bridge between RLP data
+and actual real values and takes care of all the type checking and
+casting. Unlike Go's `reflect.Value` it does not panic if it's unable to
+cast to the requested value. It simple returns the base value of that
+type (e.g. `Slice()` returns []interface{}, `Uint()` return 0, etc).
+
+### Creating a new Value
+
+`NewEmptyValue()` returns a new \*Value with it's initial value set to a
+`[]interface{}`
+
+`AppendList()` appends a list to the current value.
+
+`Append(v)` appends the value (v) to the current value/list.
+
+```go
+val := ethutil.NewEmptyValue().Append(1).Append("2")
+val.AppendList().Append(3)
+```
+
+### Retrieving values
+
+`Get(i)` returns the `i` item in the list.
+
+`Uint()` returns the value as an unsigned int64.
+
+`Slice()` returns the value as a interface slice.
+
+`Str()` returns the value as a string.
+
+`Bytes()` returns the value as a byte slice.
+
+`Len()` assumes current to be a slice and returns its length.
+
+`Byte()` returns the value as a single byte.
+
+```go
+val := ethutil.NewValue([]interface{}{1,"2",[]interface{}{3}})
+val.Get(0).Uint() // => 1
+val.Get(1).Str()  // => "2"
+s := val.Get(2)   // => Value([]interface{}{3})
+s.Get(0).Uint()   // => 3
+```
+
+## Decoding
+
+Decoding streams of RLP data is simplified
+
+```go
+val := ethutil.NewValueFromBytes(rlpData)
+val.Get(0).Uint()
+```
+
+## Encoding
+
+Encoding from Value to RLP is done with the `Encode` method. The
+underlying value can be anything RLP can encode (int, str, lists, bytes)
+
+```go
+val := ethutil.NewValue([]interface{}{1,"2",[]interface{}{3}})
+rlp := val.Encode()
+// Store the rlp data
+Store(rlp)
+```
diff --git a/ethutil/big.go b/ethutil/big.go
new file mode 100644
index 000000000..bdcf86421
--- /dev/null
+++ b/ethutil/big.go
@@ -0,0 +1,104 @@
+package ethutil
+
+import "math/big"
+
+var MaxInt256 *big.Int = BigD(Hex2Bytes("ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff"))
+
+// Big pow
+//
+// Returns the power of two big integers
+func BigPow(a, b int) *big.Int {
+	c := new(big.Int)
+	c.Exp(big.NewInt(int64(a)), big.NewInt(int64(b)), big.NewInt(0))
+
+	return c
+}
+
+// Big
+//
+// Shortcut for new(big.Int).SetString(..., 0)
+func Big(num string) *big.Int {
+	n := new(big.Int)
+	n.SetString(num, 0)
+
+	return n
+}
+
+// BigD
+//
+// Shortcut for new(big.Int).SetBytes(...)
+func BigD(data []byte) *big.Int {
+	n := new(big.Int)
+	n.SetBytes(data)
+
+	return n
+}
+
+// To256
+//
+// "cast" the big int to a 256 big int (i.e., limit to)
+var tt256 = new(big.Int).Lsh(big.NewInt(1), 256)
+var tt256m1 = new(big.Int).Sub(new(big.Int).Lsh(big.NewInt(1), 256), big.NewInt(1))
+var tt255 = new(big.Int).Lsh(big.NewInt(1), 255)
+
+func U256(x *big.Int) *big.Int {
+	//if x.Cmp(Big0) < 0 {
+	//		return new(big.Int).Add(tt256, x)
+	//	}
+
+	x.And(x, tt256m1)
+
+	return x
+}
+
+func S256(x *big.Int) *big.Int {
+	if x.Cmp(tt255) < 0 {
+		return x
+	} else {
+		// We don't want to modify x, ever
+		return new(big.Int).Sub(x, tt256)
+	}
+}
+
+// Big to bytes
+//
+// Returns the bytes of a big integer with the size specified by **base**
+// Attempts to pad the byte array with zeros.
+func BigToBytes(num *big.Int, base int) []byte {
+	ret := make([]byte, base/8)
+
+	if len(num.Bytes()) > base/8 {
+		return num.Bytes()
+	}
+
+	return append(ret[:len(ret)-len(num.Bytes())], num.Bytes()...)
+}
+
+// Big copy
+//
+// Creates a copy of the given big integer
+func BigCopy(src *big.Int) *big.Int {
+	return new(big.Int).Set(src)
+}
+
+// Big max
+//
+// Returns the maximum size big integer
+func BigMax(x, y *big.Int) *big.Int {
+	if x.Cmp(y) <= 0 {
+		return y
+	}
+
+	return x
+}
+
+// Big min
+//
+// Returns the minimum size big integer
+func BigMin(x, y *big.Int) *big.Int {
+	if x.Cmp(y) >= 0 {
+		return y
+	}
+
+	return x
+}
diff --git a/ethutil/bytes.go b/ethutil/bytes.go
new file mode 100644
index 000000000..bd294f28a
--- /dev/null
+++ b/ethutil/bytes.go
@@ -0,0 +1,234 @@
+package ethutil
+
+import (
+	"bytes"
+	"encoding/binary"
+	"encoding/hex"
+	"fmt"
+	"math/big"
+	"strings"
+)
+
+type Bytes []byte
+
+func (self Bytes) String() string {
+	return string(self)
+}
+
+func DeleteFromByteSlice(s [][]byte, hash []byte) [][]byte {
+	for i, h := range s {
+		if bytes.Compare(h, hash) == 0 {
+			return append(s[:i:i], s[i+1:]...)
+		}
+	}
+
+	return s
+}
+
+// Number to bytes
+//
+// Returns the number in bytes with the specified base
+func NumberToBytes(num interface{}, bits int) []byte {
+	buf := new(bytes.Buffer)
+	err := binary.Write(buf, binary.BigEndian, num)
+	if err != nil {
+		fmt.Println("NumberToBytes failed:", err)
+	}
+
+	return buf.Bytes()[buf.Len()-(bits/8):]
+}
+
+// Bytes to number
+//
+// Attempts to cast a byte slice to a unsigned integer
+func BytesToNumber(b []byte) uint64 {
+	var number uint64
+
+	// Make sure the buffer is 64bits
+	data := make([]byte, 8)
+	data = append(data[:len(b)], b...)
+
+	buf := bytes.NewReader(data)
+	err := binary.Read(buf, binary.BigEndian, &number)
+	if err != nil {
+		fmt.Println("BytesToNumber failed:", err)
+	}
+
+	return number
+}
+
+// Read variable int
+//
+// Read a variable length number in big endian byte order
+func ReadVarInt(buff []byte) (ret uint64) {
+	switch l := len(buff); {
+	case l > 4:
+		d := LeftPadBytes(buff, 8)
+		binary.Read(bytes.NewReader(d), binary.BigEndian, &ret)
+	case l > 2:
+		var num uint32
+		d := LeftPadBytes(buff, 4)
+		binary.Read(bytes.NewReader(d), binary.BigEndian, &num)
+		ret = uint64(num)
+	case l > 1:
+		var num uint16
+		d := LeftPadBytes(buff, 2)
+		binary.Read(bytes.NewReader(d), binary.BigEndian, &num)
+		ret = uint64(num)
+	default:
+		var num uint8
+		binary.Read(bytes.NewReader(buff), binary.BigEndian, &num)
+		ret = uint64(num)
+	}
+
+	return
+}
+
+// Binary length
+//
+// Returns the true binary length of the given number
+func BinaryLength(num int) int {
+	if num == 0 {
+		return 0
+	}
+
+	return 1 + BinaryLength(num>>8)
+}
+
+// Copy bytes
+//
+// Returns an exact copy of the provided bytes
+func CopyBytes(b []byte) (copiedBytes []byte) {
+	copiedBytes = make([]byte, len(b))
+	copy(copiedBytes, b)
+
+	return
+}
+
+func IsHex(str string) bool {
+	l := len(str)
+	return l >= 4 && l%2 == 0 && str[0:2] == "0x"
+}
+
+func Bytes2Hex(d []byte) string {
+	return hex.EncodeToString(d)
+}
+
+func Hex2Bytes(str string) []byte {
+	h, _ := hex.DecodeString(str)
+
+	return h
+}
+
+func StringToByteFunc(str string, cb func(str string) []byte) (ret []byte) {
+	if len(str) > 1 && str[0:2] == "0x" && !strings.Contains(str, "\n") {
+		ret = Hex2Bytes(str[2:])
+	} else {
+		ret = cb(str)
+	}
+
+	return
+}
+
+func FormatData(data string) []byte {
+	if len(data) == 0 {
+		return nil
+	}
+	// Simple stupid
+	d := new(big.Int)
+	if data[0:1] == "\"" && data[len(data)-1:] == "\"" {
+		return RightPadBytes([]byte(data[1:len(data)-1]), 32)
+	} else if len(data) > 1 && data[:2] == "0x" {
+		d.SetBytes(Hex2Bytes(data[2:]))
+	} else {
+		d.SetString(data, 0)
+	}
+
+	return BigToBytes(d, 256)
+}
+
+func ParseData(data ...interface{}) (ret []byte) {
+	for _, item := range data {
+		switch t := item.(type) {
+		case string:
+			var str []byte
+			if IsHex(t) {
+				str = Hex2Bytes(t[2:])
+			} else {
+				str = []byte(t)
+			}
+
+			ret = append(ret, RightPadBytes(str, 32)...)
+		case []byte:
+			ret = append(ret, LeftPadBytes(t, 32)...)
+		}
+	}
+
+	return
+}
+
+func RightPadBytes(slice []byte, l int) []byte {
+	if l < len(slice) {
+		return slice
+	}
+
+	padded := make([]byte, l)
+	copy(padded[0:len(slice)], slice)
+
+	return padded
+}
+
+func LeftPadBytes(slice []byte, l int) []byte {
+	if l < len(slice) {
+		return slice
+	}
+
+	padded := make([]byte, l)
+	copy(padded[l-len(slice):], slice)
+
+	return padded
+}
+
+func LeftPadString(str string, l int) string {
+	if l < len(str) {
+		return str
+	}
+
+	zeros := Bytes2Hex(make([]byte, (l-len(str))/2))
+
+	return zeros + str
+
+}
+
+func RightPadString(str string, l int) string {
+	if l < len(str) {
+		return str
+	}
+
+	zeros := Bytes2Hex(make([]byte, (l-len(str))/2))
+
+	return str + zeros
+
+}
+
+func Address(slice []byte) (addr []byte) {
+	if len(slice) < 20 {
+		addr = LeftPadBytes(slice, 20)
+	} else if len(slice) > 20 {
+		addr = slice[len(slice)-20:]
+	} else {
+		addr = slice
+	}
+
+	addr = CopyBytes(addr)
+
+	return
+}
+
+func ByteSliceToInterface(slice [][]byte) (ret []interface{}) {
+	for _, i := range slice {
+		ret = append(ret, i)
+	}
+
+	return
+}
diff --git a/ethutil/bytes_test.go b/ethutil/bytes_test.go
new file mode 100644
index 000000000..381efe7a2
--- /dev/null
+++ b/ethutil/bytes_test.go
@@ -0,0 +1,14 @@
+package ethutil
+
+import (
+	"bytes"
+	"testing"
+)
+
+func TestParseData(t *testing.T) {
+	data := ParseData("hello", "world", "0x0106")
+	exp := "68656c6c6f000000000000000000000000000000000000000000000000000000776f726c640000000000000000000000000000000000000000000000000000000106000000000000000000000000000000000000000000000000000000000000"
+	if bytes.Compare(data, Hex2Bytes(exp)) != 0 {
+		t.Error("Error parsing data")
+	}
+}
diff --git a/ethutil/common.go b/ethutil/common.go
new file mode 100644
index 000000000..8532d80f2
--- /dev/null
+++ b/ethutil/common.go
@@ -0,0 +1,85 @@
+package ethutil
+
+import (
+	"fmt"
+	"math/big"
+	"runtime"
+)
+
+func IsWindows() bool {
+	return runtime.GOOS == "windows"
+}
+
+func WindonizePath(path string) string {
+	if string(path[0]) == "/" && IsWindows() {
+		path = path[1:]
+	}
+	return path
+}
+
+// The different number of units
+var (
+	Douglas  = BigPow(10, 42)
+	Einstein = BigPow(10, 21)
+	Ether    = BigPow(10, 18)
+	Finney   = BigPow(10, 15)
+	Szabo    = BigPow(10, 12)
+	Shannon  = BigPow(10, 9)
+	Babbage  = BigPow(10, 6)
+	Ada      = BigPow(10, 3)
+	Wei      = big.NewInt(1)
+)
+
+//
+// Currency to string
+// Returns a string representing a human readable format
+func CurrencyToString(num *big.Int) string {
+	var (
+		fin   *big.Int = num
+		denom string   = "Wei"
+	)
+
+	switch {
+	case num.Cmp(Douglas) >= 0:
+		fin = new(big.Int).Div(num, Douglas)
+		denom = "Douglas"
+	case num.Cmp(Einstein) >= 0:
+		fin = new(big.Int).Div(num, Einstein)
+		denom = "Einstein"
+	case num.Cmp(Ether) >= 0:
+		fin = new(big.Int).Div(num, Ether)
+		denom = "Ether"
+	case num.Cmp(Finney) >= 0:
+		fin = new(big.Int).Div(num, Finney)
+		denom = "Finney"
+	case num.Cmp(Szabo) >= 0:
+		fin = new(big.Int).Div(num, Szabo)
+		denom = "Szabo"
+	case num.Cmp(Shannon) >= 0:
+		fin = new(big.Int).Div(num, Shannon)
+		denom = "Shannon"
+	case num.Cmp(Babbage) >= 0:
+		fin = new(big.Int).Div(num, Babbage)
+		denom = "Babbage"
+	case num.Cmp(Ada) >= 0:
+		fin = new(big.Int).Div(num, Ada)
+		denom = "Ada"
+	}
+
+	if len(fin.String()) > 5 {
+		return fmt.Sprintf("%sE%d %s", fin.String()[0:5], len(fin.String())-5, denom)
+	}
+
+	return fmt.Sprintf("%v %s", fin, denom)
+}
+
+// Common big integers often used
+var (
+	Big1     = big.NewInt(1)
+	Big2     = big.NewInt(2)
+	Big0     = big.NewInt(0)
+	BigTrue  = Big1
+	BigFalse = Big0
+	Big32    = big.NewInt(32)
+	Big256   = big.NewInt(0xff)
+)
diff --git a/ethutil/common_test.go b/ethutil/common_test.go
new file mode 100644
index 000000000..2667eaf3a
--- /dev/null
+++ b/ethutil/common_test.go
@@ -0,0 +1,44 @@
+package ethutil
+
+import (
+	"math/big"
+	"testing"
+)
+
+func TestCommon(t *testing.T) {
+	ether := CurrencyToString(BigPow(10, 19))
+	finney := CurrencyToString(BigPow(10, 16))
+	szabo := CurrencyToString(BigPow(10, 13))
+	vito := CurrencyToString(BigPow(10, 10))
+	turing := CurrencyToString(BigPow(10, 7))
+	eins := CurrencyToString(BigPow(10, 4))
+	wei := CurrencyToString(big.NewInt(10))
+
+	if ether != "10 Ether" {
+		t.Error("Got", ether)
+	}
+
+	if finney != "10 Finney" {
+		t.Error("Got", finney)
+	}
+
+	if szabo != "10 Szabo" {
+		t.Error("Got", szabo)
+	}
+
+	if vito != "10 Shannon" {
+		t.Error("Got", vito)
+	}
+
+	if turing != "10 Babbage" {
+		t.Error("Got", turing)
+	}
+
+	if eins != "10 Ada" {
+		t.Error("Got", eins)
+	}
+
+	if wei != "10 Wei" {
+		t.Error("Got", wei)
+	}
+}
diff --git a/ethutil/config.go b/ethutil/config.go
new file mode 100644
index 000000000..ccc7714d0
--- /dev/null
+++ b/ethutil/config.go
@@ -0,0 +1,72 @@
+package ethutil
+
+import (
+	"flag"
+	"fmt"
+	"os"
+
+	"github.com/rakyll/globalconf"
+)
+
+// Config struct
+type ConfigManager struct {
+	Db Database
+
+	ExecPath string
+	Debug    bool
+	Diff     bool
+	DiffType string
+	Paranoia bool
+	VmType   int
+
+	conf *globalconf.GlobalConf
+}
+
+var Config *ConfigManager
+
+// Read config
+//
+// Initialize Config from Config File
+func ReadConfig(ConfigFile string, Datadir string, EnvPrefix string) *ConfigManager {
+	if Config == nil {
+		// create ConfigFile if does not exist, otherwise globalconf panic when trying to persist flags
+		if !FileExist(ConfigFile) {
+			fmt.Printf("config file '%s' doesn't exist, creating it\n", ConfigFile)
+			os.Create(ConfigFile)
+		}
+		g, err := globalconf.NewWithOptions(&globalconf.Options{
+			Filename:  ConfigFile,
+			EnvPrefix: EnvPrefix,
+		})
+		if err != nil {
+			fmt.Println(err)
+		} else {
+			g.ParseAll()
+		}
+		Config = &ConfigManager{ExecPath: Datadir, Debug: true, conf: g, Paranoia: true}
+	}
+	return Config
+}
+
+// provides persistence for flags
+func (c *ConfigManager) Save(key string, value interface{}) {
+	f := &flag.Flag{Name: key, Value: newConfValue(value)}
+	c.conf.Set("", f)
+}
+
+func (c *ConfigManager) Delete(key string) {
+	c.conf.Delete("", key)
+}
+
+// private type implementing flag.Value
+type confValue struct {
+	value string
+}
+
+// generic constructor to allow persising non-string values directly
+func newConfValue(value interface{}) *confValue {
+	return &confValue{fmt.Sprintf("%v", value)}
+}
+
+func (self confValue) String() string     { return self.value }
+func (self confValue) Set(s string) error { self.value = s; return nil }
diff --git a/ethutil/db.go b/ethutil/db.go
new file mode 100644
index 000000000..e02a80fca
--- /dev/null
+++ b/ethutil/db.go
@@ -0,0 +1,12 @@
+package ethutil
+
+// Database interface
+type Database interface {
+	Put(key []byte, value []byte)
+	Get(key []byte) ([]byte, error)
+	//GetKeys() []*Key
+	Delete(key []byte) error
+	LastKnownTD() []byte
+	Close()
+	Print()
+}
diff --git a/ethutil/list.go b/ethutil/list.go
new file mode 100644
index 000000000..6919a02f5
--- /dev/null
+++ b/ethutil/list.go
@@ -0,0 +1,80 @@
+package ethutil
+
+import (
+	"encoding/json"
+	"reflect"
+	"sync"
+)
+
+// The list type is an anonymous slice handler which can be used
+// for containing any slice type to use in an environment which
+// does not support slice types (e.g., JavaScript, QML)
+type List struct {
+	mut    sync.Mutex
+	val    interface{}
+	list   reflect.Value
+	Length int
+}
+
+// Initialise a new list. Panics if non-slice type is given.
+func NewList(t interface{}) *List {
+	list := reflect.ValueOf(t)
+	if list.Kind() != reflect.Slice {
+		panic("list container initialized with a non-slice type")
+	}
+
+	return &List{sync.Mutex{}, t, list, list.Len()}
+}
+
+func EmptyList() *List {
+	return NewList([]interface{}{})
+}
+
+// Get N element from the embedded slice. Returns nil if OOB.
+func (self *List) Get(i int) interface{} {
+	if self.list.Len() > i {
+		self.mut.Lock()
+		defer self.mut.Unlock()
+
+		i := self.list.Index(i).Interface()
+
+		return i
+	}
+
+	return nil
+}
+
+func (self *List) GetAsJson(i int) interface{} {
+	e := self.Get(i)
+
+	r, _ := json.Marshal(e)
+
+	return string(r)
+}
+
+// Appends value at the end of the slice. Panics when incompatible value
+// is given.
+func (self *List) Append(v interface{}) {
+	self.mut.Lock()
+	defer self.mut.Unlock()
+
+	self.list = reflect.Append(self.list, reflect.ValueOf(v))
+	self.Length = self.list.Len()
+}
+
+// Returns the underlying slice as interface.
+func (self *List) Interface() interface{} {
+	return self.list.Interface()
+}
+
+// For JavaScript <3
+func (self *List) ToJSON() string {
+	var list []interface{}
+	for i := 0; i < self.Length; i++ {
+		list = append(list, self.Get(i))
+	}
+
+	data, _ := json.Marshal(list)
+
+	return string(data)
+}
diff --git a/ethutil/package.go b/ethutil/package.go
new file mode 100644
index 000000000..e5df989d2
--- /dev/null
+++ b/ethutil/package.go
@@ -0,0 +1,123 @@
+package ethutil
+
+import (
+	"archive/zip"
+	"encoding/json"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"strings"
+)
+
+// Manifest object
+//
+// The manifest object holds all the relevant information supplied with the
+// the manifest specified in the package
+type Manifest struct {
+	Entry         string
+	Height, Width int
+}
+
+// External package
+//
+// External package contains the main html file and manifest
+type ExtPackage struct {
+	EntryHtml string
+	Manifest  *Manifest
+}
+
+// Read file
+//
+// Read a given compressed file and returns the read bytes.
+// Returns an error otherwise
+func ReadFile(f *zip.File) ([]byte, error) {
+	rc, err := f.Open()
+	if err != nil {
+		return nil, err
+	}
+	defer rc.Close()
+
+	content, err := ioutil.ReadAll(rc)
+	if err != nil {
+		return nil, err
+	}
+
+	return content, nil
+}
+
+// Reads manifest
+//
+// Reads and returns a manifest object. Returns error otherwise
+func ReadManifest(m []byte) (*Manifest, error) {
+	var manifest Manifest
+
+	dec := json.NewDecoder(strings.NewReader(string(m)))
+	if err := dec.Decode(&manifest); err == io.EOF {
+	} else if err != nil {
+		return nil, err
+	}
+
+	return &manifest, nil
+}
+
+// Find file in archive
+//
+// Returns the index of the given file name if it exists. -1 if file not found
+func FindFileInArchive(fn string, files []*zip.File) (index int) {
+	index = -1
+	// Find the manifest first
+	for i, f := range files {
+		if f.Name == fn {
+			index = i
+		}
+	}
+
+	return
+}
+
+// Open package
+//
+// Opens a prepared ethereum package
+// Reads the manifest file and determines file contents and returns and
+// the external package.
+func OpenPackage(fn string) (*ExtPackage, error) {
+	r, err := zip.OpenReader(fn)
+	if err != nil {
+		return nil, err
+	}
+	defer r.Close()
+
+	manifestIndex := FindFileInArchive("manifest.json", r.File)
+
+	if manifestIndex < 0 {
+		return nil, fmt.Errorf("No manifest file found in archive")
+	}
+
+	f, err := ReadFile(r.File[manifestIndex])
+	if err != nil {
+		return nil, err
+	}
+
+	manifest, err := ReadManifest(f)
+	if err != nil {
+		return nil, err
+	}
+
+	if manifest.Entry == "" {
+		return nil, fmt.Errorf("Entry file specified but appears to be empty: %s", manifest.Entry)
+	}
+
+	entryIndex := FindFileInArchive(manifest.Entry, r.File)
+	if entryIndex < 0 {
+		return nil, fmt.Errorf("Entry file not found: '%s'", manifest.Entry)
+	}
+
+	f, err = ReadFile(r.File[entryIndex])
+	if err != nil {
+		return nil, err
+	}
+
+	extPackage := &ExtPackage{string(f), manifest}
+
+	return extPackage, nil
+}
diff --git a/ethutil/path.go b/ethutil/path.go
new file mode 100644
index 000000000..cfbc38950
--- /dev/null
+++ b/ethutil/path.go
@@ -0,0 +1,60 @@
+package ethutil
+
+import (
+	"io/ioutil"
+	"os"
+	"os/user"
+	"strings"
+)
+
+func ExpandHomePath(p string) (path string) {
+	path = p
+
+	// Check in case of paths like "/something/~/something/"
+	if path[:2] == "~/" {
+		usr, _ := user.Current()
+		dir := usr.HomeDir
+
+		path = strings.Replace(p, "~", dir, 1)
+	}
+
+	return
+}
+
+func FileExist(filePath string) bool {
+	_, err := os.Stat(filePath)
+	if err != nil && os.IsNotExist(err) {
+		return false
+	}
+
+	return true
+}
+
+func ReadAllFile(filePath string) (string, error) {
+	file, err := os.Open(filePath)
+	if err != nil {
+		return "", err
+	}
+
+	data, err := ioutil.ReadAll(file)
+	if err != nil {
+		return "", err
+	}
+
+	return string(data), nil
+}
+
+func WriteFile(filePath string, content []byte) error {
+	fh, err := os.OpenFile(filePath, os.O_TRUNC|os.O_RDWR|os.O_CREATE, os.ModePerm)
+	if err != nil {
+		return err
+	}
+	defer fh.Close()
+
+	_, err = fh.Write(content)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
diff --git a/ethutil/rand.go b/ethutil/rand.go
new file mode 100644
index 000000000..91dafec7e
--- /dev/null
+++ b/ethutil/rand.go
@@ -0,0 +1,24 @@
+package ethutil
+
+import (
+	"crypto/rand"
+	"encoding/binary"
+	"io"
+)
+
+func randomUint64(r io.Reader) (uint64, error) {
+	b := make([]byte, 8)
+	n, err := r.Read(b)
+	if n != len(b) {
+		return 0, io.ErrShortBuffer
+	}
+	if err != nil {
+		return 0, err
+	}
+	return binary.BigEndian.Uint64(b), nil
+}
+
+// RandomUint64 returns a cryptographically random uint64 value.
+func RandomUint64() (uint64, error) {
+	return randomUint64(rand.Reader)
+}
diff --git a/ethutil/rlp.go b/ethutil/rlp.go
new file mode 100644
index 000000000..55406133b
--- /dev/null
+++ b/ethutil/rlp.go
@@ -0,0 +1,236 @@
+package ethutil
+
+import (
+	"bytes"
+	"fmt"
+	"math/big"
+)
+
+type RlpEncode interface {
+	RlpEncode() []byte
+}
+
+type RlpEncodeDecode interface {
+	RlpEncode
+	RlpValue() []interface{}
+}
+
+func Rlp(encoder RlpEncode) []byte {
+	return encoder.RlpEncode()
+}
+
+type RlpEncoder struct {
+	rlpData []byte
+}
+
+func NewRlpEncoder() *RlpEncoder {
+	encoder := &RlpEncoder{}
+
+	return encoder
+}
+func (coder *RlpEncoder) EncodeData(rlpData interface{}) []byte {
+	return Encode(rlpData)
+}
+
+const (
+	RlpEmptyList = 0x80
+	RlpEmptyStr  = 0x40
+)
+
+const rlpEof = -1
+
+func Char(c []byte) int {
+	if len(c) > 0 {
+		return int(c[0])
+	}
+
+	return rlpEof
+}
+
+func DecodeWithReader(reader *bytes.Buffer) interface{} {
+	var slice []interface{}
+
+	// Read the next byte
+	char := Char(reader.Next(1))
+	switch {
+	case char <= 0x7f:
+		return char
+
+	case char <= 0xb7:
+		return reader.Next(int(char - 0x80))
+
+	case char <= 0xbf:
+		length := ReadVarInt(reader.Next(int(char - 0xb7)))
+
+		return reader.Next(int(length))
+
+	case char <= 0xf7:
+		length := int(char - 0xc0)
+		for i := 0; i < length; i++ {
+			obj := DecodeWithReader(reader)
+			slice = append(slice, obj)
+		}
+
+		return slice
+	case char <= 0xff:
+		length := ReadVarInt(reader.Next(int(char - 0xf7)))
+		for i := uint64(0); i < length; i++ {
+			obj := DecodeWithReader(reader)
+			slice = append(slice, obj)
+		}
+
+		return slice
+	default:
+		panic(fmt.Sprintf("byte not supported: %q", char))
+	}
+
+	return slice
+}
+
+var (
+	directRlp = big.NewInt(0x7f)
+	numberRlp = big.NewInt(0xb7)
+	zeroRlp   = big.NewInt(0x0)
+)
+
+func Encode(object interface{}) []byte {
+	var buff bytes.Buffer
+
+	if object != nil {
+		switch t := object.(type) {
+		case *Value:
+			buff.Write(Encode(t.Raw()))
+		// Code dup :-/
+		case int:
+			buff.Write(Encode(big.NewInt(int64(t))))
+		case uint:
+			buff.Write(Encode(big.NewInt(int64(t))))
+		case int8:
+			buff.Write(Encode(big.NewInt(int64(t))))
+		case int16:
+			buff.Write(Encode(big.NewInt(int64(t))))
+		case int32:
+			buff.Write(Encode(big.NewInt(int64(t))))
+		case int64:
+			buff.Write(Encode(big.NewInt(t)))
+		case uint16:
+			buff.Write(Encode(big.NewInt(int64(t))))
+		case uint32:
+			buff.Write(Encode(big.NewInt(int64(t))))
+		case uint64:
+			buff.Write(Encode(big.NewInt(int64(t))))
+		case byte:
+			buff.Write(Encode(big.NewInt(int64(t))))
+		case *big.Int:
+			// Not sure how this is possible while we check for
+			if t == nil {
+				buff.WriteByte(0xc0)
+			} else {
+				buff.Write(Encode(t.Bytes()))
+			}
+		case Bytes:
+			buff.Write(Encode([]byte(t)))
+		case []byte:
+			if len(t) == 1 && t[0] <= 0x7f {
+				buff.Write(t)
+			} else if len(t) < 56 {
+				buff.WriteByte(byte(len(t) + 0x80))
+				buff.Write(t)
+			} else {
+				b := big.NewInt(int64(len(t)))
+				buff.WriteByte(byte(len(b.Bytes()) + 0xb7))
+				buff.Write(b.Bytes())
+				buff.Write(t)
+			}
+		case string:
+			buff.Write(Encode([]byte(t)))
+		case []interface{}:
+			// Inline function for writing the slice header
+			WriteSliceHeader := func(length int) {
+				if length < 56 {
+					buff.WriteByte(byte(length + 0xc0))
+				} else {
+					b := big.NewInt(int64(length))
+					buff.WriteByte(byte(len(b.Bytes()) + 0xf7))
+					buff.Write(b.Bytes())
+				}
+			}
+
+			var b bytes.Buffer
+			for _, val := range t {
+				b.Write(Encode(val))
+			}
+			WriteSliceHeader(len(b.Bytes()))
+			buff.Write(b.Bytes())
+		}
+	} else {
+		// Empty list for nil
+		buff.WriteByte(0xc0)
+	}
+
+	return buff.Bytes()
+}
+
+// TODO Use a bytes.Buffer instead of a raw byte slice.
+// Cleaner code, and use draining instead of seeking the next bytes to read
+func Decode(data []byte, pos uint64) (interface{}, uint64) {
+	var slice []interface{}
+	char := int(data[pos])
+	switch {
+	case char <= 0x7f:
+		return data[pos], pos + 1
+
+	case char <= 0xb7:
+		b := uint64(data[pos]) - 0x80
+
+		return data[pos+1 : pos+1+b], pos + 1 + b
+
+	case char <= 0xbf:
+		b := uint64(data[pos]) - 0xb7
+
+		b2 := ReadVarInt(data[pos+1 : pos+1+b])
+
+		return data[pos+1+b : pos+1+b+b2], pos + 1 + b + b2
+
+	case char <= 0xf7:
+		b := uint64(data[pos]) - 0xc0
+		prevPos := pos
+		pos++
+		for i := uint64(0); i < b; {
+			var obj interface{}
+
+			// Get the next item in the data list and append it
+			obj, prevPos = Decode(data, pos)
+			slice = append(slice, obj)
+
+			// Increment i by the amount bytes read in the previous
+			// read
+			i += (prevPos - pos)
+			pos = prevPos
+		}
+		return slice, pos
+
+	case char <= 0xff:
+		l := uint64(data[pos]) - 0xf7
+		b := ReadVarInt(data[pos+1 : pos+1+l])
+
+		pos = pos + l + 1
+
+		prevPos := b
+		for i := uint64(0); i < uint64(b); {
+			var obj interface{}
+
+			obj, prevPos = Decode(data, pos)
+			slice = append(slice, obj)
+
+			i += (prevPos - pos)
+			pos = prevPos
+		}
+		return slice, pos
+
+	default:
+		panic(fmt.Sprintf("byte not supported: %q", char))
+	}
+
+	return slice, 0
+}
diff --git a/ethutil/rlp_test.go b/ethutil/rlp_test.go
new file mode 100644
index 000000000..90057ab42
--- /dev/null
+++ b/ethutil/rlp_test.go
@@ -0,0 +1,146 @@
+package ethutil
+
+import (
+	"bytes"
+	"math/big"
+	"reflect"
+	"testing"
+)
+
+func TestRlpValueEncoding(t *testing.T) {
+	val := EmptyValue()
+	val.AppendList().Append(1).Append(2).Append(3)
+	val.Append("4").AppendList().Append(5)
+
+	res := val.Encode()
+	exp := Encode([]interface{}{[]interface{}{1, 2, 3}, "4", []interface{}{5}})
+	if bytes.Compare(res, exp) != 0 {
+		t.Errorf("expected %q, got %q", res, exp)
+	}
+}
+
+func TestValueSlice(t *testing.T) {
+	val := []interface{}{
+		"value1",
+		"valeu2",
+		"value3",
+	}
+
+	value := NewValue(val)
+	splitVal := value.SliceFrom(1)
+
+	if splitVal.Len() != 2 {
+		t.Error("SliceFrom: Expected len", 2, "got", splitVal.Len())
+	}
+
+	splitVal = value.SliceTo(2)
+	if splitVal.Len() != 2 {
+		t.Error("SliceTo: Expected len", 2, "got", splitVal.Len())
+	}
+
+	splitVal = value.SliceFromTo(1, 3)
+	if splitVal.Len() != 2 {
+		t.Error("SliceFromTo: Expected len", 2, "got", splitVal.Len())
+	}
+}
+
+func TestLargeData(t *testing.T) {
+	data := make([]byte, 100000)
+	enc := Encode(data)
+	value := NewValue(enc)
+	value.Decode()
+
+	if value.Len() != len(data) {
+		t.Error("Expected data to be", len(data), "got", value.Len())
+	}
+}
+
+func TestValue(t *testing.T) {
+	value := NewValueFromBytes([]byte("\xcd\x83dog\x83god\x83cat\x01"))
+	if value.Get(0).Str() != "dog" {
+		t.Errorf("expected '%v', got '%v'", value.Get(0).Str(), "dog")
+	}
+
+	if value.Get(3).Uint() != 1 {
+		t.Errorf("expected '%v', got '%v'", value.Get(3).Uint(), 1)
+	}
+}
+
+func TestEncode(t *testing.T) {
+	strRes := "\x83dog"
+	bytes := Encode("dog")
+
+	str := string(bytes)
+	if str != strRes {
+		t.Errorf("Expected %q, got %q", strRes, str)
+	}
+
+	sliceRes := "\xcc\x83dog\x83god\x83cat"
+	strs := []interface{}{"dog", "god", "cat"}
+	bytes = Encode(strs)
+	slice := string(bytes)
+	if slice != sliceRes {
+		t.Error("Expected %q, got %q", sliceRes, slice)
+	}
+
+	intRes := "\x82\x04\x00"
+	bytes = Encode(1024)
+	if string(bytes) != intRes {
+		t.Errorf("Expected %q, got %q", intRes, bytes)
+	}
+}
+
+func TestDecode(t *testing.T) {
+	single := []byte("\x01")
+	b, _ := Decode(single, 0)
+
+	if b.(uint8) != 1 {
+		t.Errorf("Expected 1, got %q", b)
+	}
+
+	str := []byte("\x83dog")
+	b, _ = Decode(str, 0)
+	if bytes.Compare(b.([]byte), []byte("dog")) != 0 {
+		t.Errorf("Expected dog, got %q", b)
+	}
+
+	slice := []byte("\xcc\x83dog\x83god\x83cat")
+	res := []interface{}{"dog", "god", "cat"}
+	b, _ = Decode(slice, 0)
+	if reflect.DeepEqual(b, res) {
+		t.Errorf("Expected %q, got %q", res, b)
+	}
+}
+
+func TestEncodeDecodeBigInt(t *testing.T) {
+	bigInt := big.NewInt(1391787038)
+	encoded := Encode(bigInt)
+
+	value := NewValueFromBytes(encoded)
+	if value.BigInt().Cmp(bigInt) != 0 {
+		t.Errorf("Expected %v, got %v", bigInt, value.BigInt())
+	}
+}
+
+func TestEncodeDecodeBytes(t *testing.T) {
+	b := NewValue([]interface{}{[]byte{1, 2, 3, 4, 5}, byte(6)})
+	val := NewValueFromBytes(b.Encode())
+	if !b.Cmp(val) {
+		t.Errorf("Expected %v, got %v", val, b)
+	}
+}
+
+func TestEncodeZero(t *testing.T) {
+	b := NewValue(0).Encode()
+	exp := []byte{0xc0}
+	if bytes.Compare(b, exp) == 0 {
+		t.Error("Expected", exp, "got", b)
+	}
+}
+
+func BenchmarkEncodeDecode(b *testing.B) {
+	for i := 0; i < b.N; i++ {
+		bytes := Encode([]interface{}{"dog", "god", "cat"})
+		Decode(bytes, 0)
+	}
+}
diff --git a/ethutil/script_unix.go b/ethutil/script_unix.go
new file mode 100644
index 000000000..bd087e7e0
--- /dev/null
+++ b/ethutil/script_unix.go
@@ -0,0 +1,47 @@
+package ethutil
+
+import (
+	"fmt"
+	"strings"
+
+	"github.com/obscuren/mutan"
+	"github.com/obscuren/mutan/backends"
+	"github.com/obscuren/serpent-go"
+)
+
+// General compile function
+func Compile(script string, silent bool) (ret []byte, err error) {
+	if len(script) > 2 {
+		line := strings.Split(script, "\n")[0]
+
+		if len(line) > 1 && line[0:2] == "#!" {
+			switch line {
+			case "#!serpent":
+				byteCode, err := serpent.Compile(script)
+				if err != nil {
+					return nil, err
+				}
+
+				return byteCode, nil
+			}
+		} else {
+
+			compiler := mutan.NewCompiler(backend.NewEthereumBackend())
+			compiler.Silent = silent
+			byteCode, errors := compiler.Compile(strings.NewReader(script))
+			if len(errors) > 0 {
+				var errs string
+				for _, er := range errors {
+					if er != nil {
+						errs += er.Error()
+					}
+				}
+				return nil, fmt.Errorf("%v", errs)
+			}
+
+			return byteCode, nil
+		}
+	}
+
+	return nil, nil
+}
diff --git a/ethutil/script_windows.go b/ethutil/script_windows.go
new file mode 100644
index 000000000..4f94c6448
--- /dev/null
+++ b/ethutil/script_windows.go
@@ -0,0 +1,31 @@
+package ethutil
+
+import (
+	"fmt"
+	"strings"
+
+	"github.com/obscuren/mutan"
+	"github.com/obscuren/mutan/backends"
+)
+
+// General compile function
+func Compile(script string, silent bool) (ret []byte, err error) {
+	if len(script) > 2 {
+		compiler := mutan.NewCompiler(backend.NewEthereumBackend())
+		compiler.Silent = silent
+		byteCode, errors := compiler.Compile(strings.NewReader(script))
+		if len(errors) > 0 {
+			var errs string
+			for _, er := range errors {
+				if er != nil {
+					errs += er.Error()
+				}
+			}
+			return nil, fmt.Errorf("%v", errs)
+		}
+
+		return byteCode, nil
+	}
+
+	return nil, nil
+}
diff --git a/ethutil/set.go b/ethutil/set.go
new file mode 100644
index 000000000..7955edac0
--- /dev/null
+++ b/ethutil/set.go
@@ -0,0 +1,36 @@
+package ethutil
+
+type Settable interface {
+	AsSet() UniqueSet
+}
+
+type Stringable interface {
+	String() string
+}
+
+type UniqueSet map[string]struct{}
+
+func NewSet(v ...Stringable) UniqueSet {
+	set := make(UniqueSet)
+	for _, val := range v {
+		set.Insert(val)
+	}
+
+	return set
+}
+
+func (self UniqueSet) Insert(k Stringable) UniqueSet {
+	self[k.String()] = struct{}{}
+
+	return self
+}
+
+func (self UniqueSet) Include(k Stringable) bool {
+	_, ok := self[k.String()]
+
+	return ok
+}
+
+func Set(s Settable) UniqueSet {
+	return s.AsSet()
+}
diff --git a/ethutil/size.go b/ethutil/size.go
new file mode 100644
index 000000000..b4426465e
--- /dev/null
+++ b/ethutil/size.go
@@ -0,0 +1,15 @@
+package ethutil
+
+import "fmt"
+
+type StorageSize float64
+
+func (self StorageSize) String() string {
+	if self > 1000000 {
+		return fmt.Sprintf("%.2f mB", self/1000000)
+	} else if self > 1000 {
+		return fmt.Sprintf("%.2f kB", self/1000)
+	} else {
+		return fmt.Sprintf("%.2f B", self)
+	}
+}
diff --git a/ethutil/size_test.go b/ethutil/size_test.go
new file mode 100644
index 000000000..82aa1c653
--- /dev/null
+++ b/ethutil/size_test.go
@@ -0,0 +1,12 @@
+package ethutil
+
+import (
+	"fmt"
+	"testing"
+)
+
+func TestSize(t *testing.T) {
+	fmt.Println(StorageSize(2381273))
+	fmt.Println(StorageSize(2192))
+	fmt.Println(StorageSize(12))
+}
diff --git a/ethutil/value.go b/ethutil/value.go
new file mode 100644
index 000000000..dd777fa43
--- /dev/null
+++ b/ethutil/value.go
@@ -0,0 +1,397 @@
+package ethutil
+
+import (
+	"bytes"
+	"fmt"
+	"math/big"
+	"reflect"
+	"strconv"
+)
+
+// Data values are returned by the rlp decoder. The data values represents
+// one item within the rlp data structure. It's responsible for all the casting
+// It always returns something valid
+type Value struct {
+	Val  interface{}
+	kind reflect.Value
+}
+
+func (val *Value) String() string {
+	return fmt.Sprintf("%x", val.Val)
+}
+
+func NewValue(val interface{}) *Value {
+	t := val
+	if v, ok := val.(*Value); ok {
+		t = v.Val
+	}
+
+	return &Value{Val: t}
+}
+
+func (val *Value) Type() reflect.Kind {
+	return reflect.TypeOf(val.Val).Kind()
+}
+
+func (val *Value) IsNil() bool {
+	return val.Val == nil
+}
+
+func (val *Value) Len() int {
+	//return val.kind.Len()
+	if data, ok := val.Val.([]interface{}); ok {
+		return len(data)
+	}
+
+	return len(val.Bytes())
+}
+
+func (val *Value) Raw() interface{} {
+	return val.Val
+}
+
+func (val *Value) Interface() interface{} {
+	return val.Val
+}
+
+func (val *Value) Uint() uint64 {
+	if Val, ok := val.Val.(uint8); ok {
+		return uint64(Val)
+	} else if Val, ok := val.Val.(uint16); ok {
+		return uint64(Val)
+	} else if Val, ok := val.Val.(uint32); ok {
+		return uint64(Val)
+	} else if Val, ok := val.Val.(uint64); ok {
+		return Val
+	} else if Val, ok := val.Val.(float32); ok {
+		return uint64(Val)
+	} else if Val, ok := val.Val.(float64); ok {
+		return uint64(Val)
+	} else if Val, ok := val.Val.(int); ok {
+		return uint64(Val)
+	} else if Val, ok := val.Val.(uint); ok {
+		return uint64(Val)
+	} else if Val, ok := val.Val.([]byte); ok {
+		return new(big.Int).SetBytes(Val).Uint64()
+	} else if Val, ok := val.Val.(*big.Int); ok {
+		return Val.Uint64()
+	}
+
+	return 0
+}
+
+func (val *Value) Int() int64 {
+	if Val, ok := val.Val.(int8); ok {
+		return int64(Val)
+	} else if Val, ok := val.Val.(int16); ok {
+		return int64(Val)
+	} else if Val, ok := val.Val.(int32); ok {
+		return int64(Val)
+	} else if Val, ok := val.Val.(int64); ok {
+		return Val
+	} else if Val, ok := val.Val.(int); ok {
+		return int64(Val)
+	} else if Val, ok := val.Val.(float32); ok {
+		return int64(Val)
+	} else if Val, ok := val.Val.(float64); ok {
+		return int64(Val)
+	} else if Val, ok := val.Val.([]byte); ok {
+		return new(big.Int).SetBytes(Val).Int64()
+	} else if Val, ok := val.Val.(*big.Int); ok {
+		return Val.Int64()
+	} else if Val, ok := val.Val.(string); ok {
+		n, _ := strconv.Atoi(Val)
+		return int64(n)
+	}
+
+	return 0
+}
+
+func (val *Value) Byte() byte {
+	if Val, ok := val.Val.(byte); ok {
+		return Val
+	}
+
+	return 0x0
+}
+
+func (val *Value) BigInt() *big.Int {
+	if a, ok := val.Val.([]byte); ok {
+		b := new(big.Int).SetBytes(a)
+
+		return b
+	} else if a, ok := val.Val.(*big.Int); ok {
+		return a
+	} else if a, ok := val.Val.(string); ok {
+		return Big(a)
+	} else {
+		return big.NewInt(int64(val.Uint()))
+	}
+
+	return big.NewInt(0)
+}
+
+func (val *Value) Str() string {
+	if a, ok := val.Val.([]byte); ok {
+		return string(a)
+	} else if a, ok := val.Val.(string); ok {
+		return a
+	} else if a, ok := val.Val.(byte); ok {
+		return string(a)
+	}
+
+	return ""
+}
+
+func (val *Value) Bytes() []byte {
+	if a, ok := val.Val.([]byte); ok {
+		return a
+	} else if s, ok := val.Val.(byte); ok {
+		return []byte{s}
+	} else if s, ok := val.Val.(string); ok {
+		return []byte(s)
+	} else if s, ok := val.Val.(*big.Int); ok {
+		return s.Bytes()
+	} else {
+		return big.NewInt(val.Int()).Bytes()
+	}
+
+	return []byte{}
+}
+
+func (val *Value) Err() error {
+	if err, ok := val.Val.(error); ok {
+		return err
+	}
+
+	return nil
+}
+
+func (val *Value) Slice() []interface{} {
+	if d, ok := val.Val.([]interface{}); ok {
+		return d
+	}
+
+	return []interface{}{}
+}
+
+func (val *Value) SliceFrom(from int) *Value {
+	slice := val.Slice()
+
+	return NewValue(slice[from:])
+}
+
+func (val *Value) SliceTo(to int) *Value {
+	slice := val.Slice()
+
+	return NewValue(slice[:to])
+}
+
+func (val *Value) SliceFromTo(from, to int) *Value {
+	slice := val.Slice()
+
+	return NewValue(slice[from:to])
+}
+
+// TODO More type checking methods
+func (val *Value) IsSlice() bool {
+	return val.Type() == reflect.Slice
+}
+
+func (val *Value) IsStr() bool {
+	return val.Type() == reflect.String
+}
+
+func (self *Value) IsErr() bool {
+	_, ok := self.Val.(error)
+	return ok
+}
+
+// Special list checking function. Something is considered
+// a list if it's of type []interface{}. The list is usually
+// used in conjunction with rlp decoded streams.
+func (val *Value) IsList() bool {
+	_, ok := val.Val.([]interface{})
+
+	return ok
+}
+
+func (val *Value) IsEmpty() bool {
+	return val.Val == nil || ((val.IsSlice() || val.IsStr()) && val.Len() == 0)
+}
+
+// Threat the value as a slice
+func (val *Value) Get(idx int) *Value {
+	if d, ok := val.Val.([]interface{}); ok {
+		// Guard for oob
+		if len(d) <= idx {
+			return NewValue(nil)
+		}
+
+		if idx < 0 {
+			return NewValue(nil)
+		}
+
+		return NewValue(d[idx])
+	}
+
+	// If this wasn't a slice you probably shouldn't be using this function
+	return NewValue(nil)
+}
+
+func (self *Value) Copy() *Value {
+	switch val := self.Val.(type) {
+	case *big.Int:
+		return NewValue(new(big.Int).Set(val))
+	case []byte:
+		return NewValue(CopyBytes(val))
+	default:
+		return NewValue(self.Val)
+	}
+
+	return nil
+}
+
+func (val *Value) Cmp(o *Value) bool {
+	return reflect.DeepEqual(val.Val, o.Val)
+}
+
+func (self *Value) DeepCmp(o *Value) bool {
+	return bytes.Compare(self.Bytes(), o.Bytes()) == 0
+}
+
+func (val *Value) Encode() []byte {
+	return Encode(val.Val)
+}
+
+// Assume that the data we have is encoded
+func (self *Value) Decode() {
+	v, _ := Decode(self.Bytes(), 0)
+	self.Val = v
+	//self.Val = DecodeWithReader(bytes.NewBuffer(self.Bytes()))
+}
+
+func NewValueFromBytes(data []byte) *Value {
+	if len(data) != 0 {
+		value := NewValue(data)
+		value.Decode()
+
+		return value
+	}
+
+	return NewValue(nil)
+}
+
+// Value setters
+func NewSliceValue(s interface{}) *Value {
+	list := EmptyValue()
+
+	if s != nil {
+		if slice, ok := s.([]interface{}); ok {
+			for _, val := range slice {
+				list.Append(val)
+			}
+		} else if slice, ok := s.([]string); ok {
+			for _, val := range slice {
+				list.Append(val)
+			}
+		}
+	}
+
+	return list
+}
+
+func EmptyValue() *Value {
+	return NewValue([]interface{}{})
+}
+
+func (val *Value) AppendList() *Value {
+	list := EmptyValue()
+	val.Val = append(val.Slice(), list)
+
+	return list
+}
+
+func (val *Value) Append(v interface{}) *Value {
+	val.Val = append(val.Slice(), v)
+
+	return val
+}
+
+const (
+	valOpAdd = iota
+	valOpDiv
+	valOpMul
+	valOpPow
+	valOpSub
+)
+
+// Math stuff
+func (self *Value) doOp(op int, other interface{}) *Value {
+	left := self.BigInt()
+	right := NewValue(other).BigInt()
+
+	switch op {
+	case valOpAdd:
+		self.Val = left.Add(left, right)
+	case valOpDiv:
+		self.Val = left.Div(left, right)
+	case valOpMul:
+		self.Val = left.Mul(left, right)
+	case valOpPow:
+		self.Val = left.Exp(left, right, Big0)
+	case valOpSub:
+		self.Val = left.Sub(left, right)
+	}
+
+	return self
+}
+
+func (self *Value) Add(other interface{}) *Value {
+	return self.doOp(valOpAdd, other)
+}
+
+func (self *Value) Sub(other interface{}) *Value {
+	return self.doOp(valOpSub, other)
+}
+
+func (self *Value) Div(other interface{}) *Value {
+	return self.doOp(valOpDiv, other)
+}
+
+func (self *Value) Mul(other interface{}) *Value {
+	return self.doOp(valOpMul, other)
+}
+
+func (self *Value) Pow(other interface{}) *Value {
+	return self.doOp(valOpPow, other)
+}
+
+type ValueIterator struct {
+	value        *Value
+	currentValue *Value
+	idx          int
+}
+
+func (val *Value) NewIterator() *ValueIterator {
+	return &ValueIterator{value: val}
+}
+
+func (it *ValueIterator) Next() bool {
+	if it.idx >= it.value.Len() {
+		return false
+	}
+
+	it.currentValue = it.value.Get(it.idx)
+	it.idx++
+
+	return true
+}
+
+func (it *ValueIterator) Value() *Value {
+	return it.currentValue
+}
+
+func (it *ValueIterator) Idx() int {
+	return it.idx
+}
diff --git a/ethutil/value_test.go b/ethutil/value_test.go
new file mode 100644
index 000000000..5452a0790
--- /dev/null
+++ b/ethutil/value_test.go
@@ -0,0 +1,86 @@
+package ethutil
+
+import (
+	"bytes"
+	"fmt"
+	"math/big"
+	"testing"
+)
+
+func TestValueCmp(t *testing.T) {
+	val1 := NewValue("hello")
+	val2 := NewValue("world")
+	if val1.Cmp(val2) {
+		t.Error("Expected values not to be equal")
+	}
+
+	val3 := NewValue("hello")
+	val4 := NewValue("hello")
+	if !val3.Cmp(val4) {
+		t.Error("Expected values to be equal")
+	}
+}
+
+func TestValueTypes(t *testing.T) {
+	str := NewValue("str")
+	num := NewValue(1)
+	inter := NewValue([]interface{}{1})
+	byt := NewValue([]byte{1, 2, 3, 4})
+	bigInt := NewValue(big.NewInt(10))
+
+	if str.Str() != "str" {
+		t.Errorf("expected Str to return 'str', got %s", str.Str())
+	}
+
+	if num.Uint() != 1 {
+		t.Errorf("expected Uint to return '1', got %d", num.Uint())
+	}
+
+	interExp := []interface{}{1}
+	if !NewValue(inter.Interface()).Cmp(NewValue(interExp)) {
+		t.Errorf("expected Interface to return '%v', got %v", interExp, num.Interface())
+	}
+
+	bytExp := []byte{1, 2, 3, 4}
+	if bytes.Compare(byt.Bytes(), bytExp) != 0 {
+		t.Errorf("expected Bytes to return '%v', got %v", bytExp, byt.Bytes())
+	}
+
+	bigExp := big.NewInt(10)
+	if bigInt.BigInt().Cmp(bigExp) != 0 {
+		t.Errorf("expected BigInt to return '%v', got %v", bigExp, bigInt.BigInt())
+	}
+}
+
+func TestIterator(t *testing.T) {
+	value := NewValue([]interface{}{1, 2, 3})
+	it := value.NewIterator()
+	values := []uint64{1, 2, 3}
+	i := 0
+	for it.Next() {
+		if values[i] != it.Value().Uint() {
+			t.Errorf("Expected %d, got %d", values[i], it.Value().Uint())
+		}
+		i++
+	}
+}
+
+func TestMath(t *testing.T) {
+	a := NewValue(1)
+	a.Add(1).Add(1)
+
+	if !a.DeepCmp(NewValue(3)) {
+		t.Error("Expected 3, got", a)
+	}
+
+	a = NewValue(2)
+	a.Sub(1).Sub(1)
+	if !a.DeepCmp(NewValue(0)) {
+		t.Error("Expected 0, got", a)
+	}
+}
+
+func TestString(t *testing.T) {
+	a := NewValue("10")
+	fmt.Println("VALUE WITH STRING:", a.Int())
+}