Merge branch 'release/0.6.3'

11 files changed, 352 insertions, 219 deletions

diff --git a/ethutil/bytes.go b/ethutil/bytes.go
index 34fff7d42..e38f89454 100644
--- a/ethutil/bytes.go
+++ b/ethutil/bytes.go
@@ -44,26 +44,28 @@ func BytesToNumber(b []byte) uint64 {
 // Read variable int
 //
 // Read a variable length number in big endian byte order
-func ReadVarint(reader *bytes.Reader) (ret uint64) {
-	if reader.Len() == 8 {
-		var num uint64
-		binary.Read(reader, binary.BigEndian, &num)
-		ret = uint64(num)
-	} else if reader.Len() == 4 {
+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
-		binary.Read(reader, binary.BigEndian, &num)
+		d := LeftPadBytes(buff, 4)
+		binary.Read(bytes.NewReader(d), binary.BigEndian, &num)
 		ret = uint64(num)
-	} else if reader.Len() == 2 {
+	case l > 1:
 		var num uint16
-		binary.Read(reader, binary.BigEndian, &num)
+		d := LeftPadBytes(buff, 2)
+		binary.Read(bytes.NewReader(d), binary.BigEndian, &num)
 		ret = uint64(num)
-	} else {
+	default:
 		var num uint8
-		binary.Read(reader, binary.BigEndian, &num)
+		binary.Read(bytes.NewReader(buff), binary.BigEndian, &num)
 		ret = uint64(num)
 	}
 
-	return ret
+	return
 }
 
 // Binary length
@@ -98,6 +100,7 @@ func Bytes2Hex(d []byte) string {
 
 func Hex2Bytes(str string) []byte {
 	h, _ := hex.DecodeString(str)
+
 	return h
 }
 
@@ -128,6 +131,26 @@ func FormatData(data string) []byte {
 	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
@@ -150,6 +173,28 @@ func LeftPadBytes(slice []byte, l int) []byte {
 	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)
@@ -163,3 +208,11 @@ func Address(slice []byte) (addr []byte) {
 
 	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
index cbd94e7ad..8532d80f2 100644
--- a/ethutil/common.go
+++ b/ethutil/common.go
@@ -34,26 +34,43 @@ var (
 // 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:
-		return fmt.Sprintf("%v Douglas", new(big.Int).Div(num, Douglas))
+		fin = new(big.Int).Div(num, Douglas)
+		denom = "Douglas"
 	case num.Cmp(Einstein) >= 0:
-		return fmt.Sprintf("%v Einstein", new(big.Int).Div(num, Einstein))
+		fin = new(big.Int).Div(num, Einstein)
+		denom = "Einstein"
 	case num.Cmp(Ether) >= 0:
-		return fmt.Sprintf("%v Ether", new(big.Int).Div(num, Ether))
+		fin = new(big.Int).Div(num, Ether)
+		denom = "Ether"
 	case num.Cmp(Finney) >= 0:
-		return fmt.Sprintf("%v Finney", new(big.Int).Div(num, Finney))
+		fin = new(big.Int).Div(num, Finney)
+		denom = "Finney"
 	case num.Cmp(Szabo) >= 0:
-		return fmt.Sprintf("%v Szabo", new(big.Int).Div(num, Szabo))
+		fin = new(big.Int).Div(num, Szabo)
+		denom = "Szabo"
 	case num.Cmp(Shannon) >= 0:
-		return fmt.Sprintf("%v Shannon", new(big.Int).Div(num, Shannon))
+		fin = new(big.Int).Div(num, Shannon)
+		denom = "Shannon"
 	case num.Cmp(Babbage) >= 0:
-		return fmt.Sprintf("%v Babbage", new(big.Int).Div(num, Babbage))
+		fin = new(big.Int).Div(num, Babbage)
+		denom = "Babbage"
 	case num.Cmp(Ada) >= 0:
-		return fmt.Sprintf("%v Ada", new(big.Int).Div(num, Ada))
+		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 Wei", num)
+	return fmt.Sprintf("%v %s", fin, denom)
 }
 
 // Common big integers often used
diff --git a/ethutil/config.go b/ethutil/config.go
index 41bece21d..81052318e 100644
--- a/ethutil/config.go
+++ b/ethutil/config.go
@@ -3,8 +3,9 @@ package ethutil
 import (
 	"flag"
 	"fmt"
-	"github.com/rakyll/globalconf"
 	"os"
+
+	"github.com/rakyll/globalconf"
 )
 
 // Config struct
@@ -28,8 +29,7 @@ var Config *ConfigManager
 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
-		_, err := os.Stat(ConfigFile)
-		if err != nil && os.IsNotExist(err) {
+		if !FileExist(ConfigFile) {
 			fmt.Printf("config file '%s' doesn't exist, creating it\n", ConfigFile)
 			os.Create(ConfigFile)
 		}
diff --git a/ethutil/path.go b/ethutil/path.go
index 97f58ab7e..27022bcfa 100644
--- a/ethutil/path.go
+++ b/ethutil/path.go
@@ -1,6 +1,8 @@
 package ethutil
 
 import (
+	"io/ioutil"
+	"os"
 	"os/user"
 	"strings"
 )
@@ -18,3 +20,41 @@ func ExpandHomePath(p string) (path string) {
 
 	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_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/reactor.go b/ethutil/reactor.go
deleted file mode 100644
index 7cf145245..000000000
--- a/ethutil/reactor.go
+++ /dev/null
@@ -1,87 +0,0 @@
-package ethutil
-
-import (
-	"sync"
-)
-
-type ReactorEvent struct {
-	mut   sync.Mutex
-	event string
-	chans []chan React
-}
-
-// Post the specified reactor resource on the channels
-// currently subscribed
-func (e *ReactorEvent) Post(react React) {
-	e.mut.Lock()
-	defer e.mut.Unlock()
-
-	for _, ch := range e.chans {
-		go func(ch chan React) {
-			ch <- react
-		}(ch)
-	}
-}
-
-// Add a subscriber to this event
-func (e *ReactorEvent) Add(ch chan React) {
-	e.mut.Lock()
-	defer e.mut.Unlock()
-
-	e.chans = append(e.chans, ch)
-}
-
-// Remove a subscriber
-func (e *ReactorEvent) Remove(ch chan React) {
-	e.mut.Lock()
-	defer e.mut.Unlock()
-
-	for i, c := range e.chans {
-		if c == ch {
-			e.chans = append(e.chans[:i], e.chans[i+1:]...)
-		}
-	}
-}
-
-// Basic reactor resource
-type React struct {
-	Resource interface{}
-	Event    string
-}
-
-// The reactor basic engine. Acts as bridge
-// between the events and the subscribers/posters
-type ReactorEngine struct {
-	patterns map[string]*ReactorEvent
-}
-
-func NewReactorEngine() *ReactorEngine {
-	return &ReactorEngine{patterns: make(map[string]*ReactorEvent)}
-}
-
-// Subscribe a channel to the specified event
-func (reactor *ReactorEngine) Subscribe(event string, ch chan React) {
-	ev := reactor.patterns[event]
-	// Create a new event if one isn't available
-	if ev == nil {
-		ev = &ReactorEvent{event: event}
-		reactor.patterns[event] = ev
-	}
-
-	// Add the channel to reactor event handler
-	ev.Add(ch)
-}
-
-func (reactor *ReactorEngine) Unsubscribe(event string, ch chan React) {
-	ev := reactor.patterns[event]
-	if ev != nil {
-		ev.Remove(ch)
-	}
-}
-
-func (reactor *ReactorEngine) Post(event string, resource interface{}) {
-	ev := reactor.patterns[event]
-	if ev != nil {
-		ev.Post(React{Resource: resource, Event: event})
-	}
-}
diff --git a/ethutil/reactor_test.go b/ethutil/reactor_test.go
deleted file mode 100644
index 48c2f0df3..000000000
--- a/ethutil/reactor_test.go
+++ /dev/null
@@ -1,30 +0,0 @@
-package ethutil
-
-import "testing"
-
-func TestReactorAdd(t *testing.T) {
-	engine := NewReactorEngine()
-	ch := make(chan React)
-	engine.Subscribe("test", ch)
-	if len(engine.patterns) != 1 {
-		t.Error("Expected patterns to be 1, got", len(engine.patterns))
-	}
-}
-
-func TestReactorEvent(t *testing.T) {
-	engine := NewReactorEngine()
-
-	// Buffer 1, so it doesn't block for this test
-	ch := make(chan React, 1)
-	engine.Subscribe("test", ch)
-	engine.Post("test", "hello")
-
-	value := <-ch
-	if val, ok := value.Resource.(string); ok {
-		if val != "hello" {
-			t.Error("Expected Resource to be 'hello', got", val)
-		}
-	} else {
-		t.Error("Unable to cast")
-	}
-}
diff --git a/ethutil/rlp.go b/ethutil/rlp.go
index 195ef0efb..17ff627eb 100644
--- a/ethutil/rlp.go
+++ b/ethutil/rlp.go
@@ -2,15 +2,16 @@ package ethutil
 
 import (
 	"bytes"
-	_ "encoding/binary"
 	"fmt"
-	_ "log"
-	_ "math"
 	"math/big"
 )
 
-type RlpEncodable interface {
+type RlpEncode interface {
 	RlpEncode() []byte
+}
+
+type RlpEncodeDecode interface {
+	RlpEncode
 	RlpValue() []interface{}
 }
 
@@ -32,12 +33,14 @@ const (
 	RlpEmptyStr  = 0x40
 )
 
+const rlpEof = -1
+
 func Char(c []byte) int {
 	if len(c) > 0 {
 		return int(c[0])
 	}
 
-	return 0
+	return rlpEof
 }
 
 func DecodeWithReader(reader *bytes.Buffer) interface{} {
@@ -46,8 +49,6 @@ func DecodeWithReader(reader *bytes.Buffer) interface{} {
 	// Read the next byte
 	char := Char(reader.Next(1))
 	switch {
-	case char == 0:
-		return nil
 	case char <= 0x7f:
 		return char
 
@@ -55,8 +56,7 @@ func DecodeWithReader(reader *bytes.Buffer) interface{} {
 		return reader.Next(int(char - 0x80))
 
 	case char <= 0xbf:
-		buff := bytes.NewReader(reader.Next(int(char - 0xb8)))
-		length := ReadVarint(buff)
+		length := ReadVarInt(reader.Next(int(char - 0xb7)))
 
 		return reader.Next(int(length))
 
@@ -64,82 +64,23 @@ func DecodeWithReader(reader *bytes.Buffer) interface{} {
 		length := int(char - 0xc0)
 		for i := 0; i < length; i++ {
 			obj := DecodeWithReader(reader)
-			if obj != nil {
-				slice = append(slice, obj)
-			} else {
-				break
-			}
-		}
-
-		return slice
-
-	}
-
-	return slice
-}
-
-// 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(bytes.NewReader(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
 
+		return slice
 	case char <= 0xff:
-		l := uint64(data[pos]) - 0xf7
-		b := ReadVarint(bytes.NewReader(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)
+		length := ReadVarInt(reader.Next(int(char - 0xf7)))
+		for i := uint64(0); i < length; i++ {
+			obj := DecodeWithReader(reader)
 			slice = append(slice, obj)
-
-			i += (prevPos - pos)
-			pos = prevPos
 		}
-		return slice, pos
 
+		return slice
 	default:
 		panic(fmt.Sprintf("byte not supported: %q", char))
 	}
 
-	return slice, 0
+	return slice
 }
 
 var (
@@ -223,3 +164,67 @@ func Encode(object interface{}) []byte {
 
 	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
index 095c01ecc..90057ab42 100644
--- a/ethutil/rlp_test.go
+++ b/ethutil/rlp_test.go
@@ -44,6 +44,17 @@ func TestValueSlice(t *testing.T) {
 	}
 }
 
+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" {
diff --git a/ethutil/value.go b/ethutil/value.go
index 735a71dbc..608d332ba 100644
--- a/ethutil/value.go
+++ b/ethutil/value.go
@@ -1,7 +1,6 @@
 package ethutil
 
 import (
-	"bytes"
 	"fmt"
 	"math/big"
 	"reflect"
@@ -67,7 +66,7 @@ func (val *Value) Uint() uint64 {
 	} else if Val, ok := val.Val.(uint); ok {
 		return uint64(Val)
 	} else if Val, ok := val.Val.([]byte); ok {
-		return ReadVarint(bytes.NewReader(Val))
+		return new(big.Int).SetBytes(Val).Uint64()
 	} else if Val, ok := val.Val.(*big.Int); ok {
 		return Val.Uint64()
 	}
@@ -75,6 +74,30 @@ func (val *Value) Uint() 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()
+	}
+
+	return 0
+}
+
 func (val *Value) Byte() byte {
 	if Val, ok := val.Val.(byte); ok {
 		return Val
@@ -123,6 +146,14 @@ func (val *Value) Bytes() []byte {
 	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
@@ -158,6 +189,11 @@ 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.
@@ -207,6 +243,13 @@ func (val *Value) Cmp(o *Value) bool {
 	return reflect.DeepEqual(val.Val, o.Val)
 }
 
+func (self *Value) DeepCmp(o *Value) bool {
+	a := NewValue(self.BigInt())
+	b := NewValue(o.BigInt())
+
+	return a.Cmp(b)
+}
+
 func (val *Value) Encode() []byte {
 	return Encode(val.Val)
 }
@@ -215,12 +258,15 @@ func (val *Value) Encode() []byte {
 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 {
-		data, _ := Decode(data, 0)
-		return NewValue(data)
+		value := NewValue(data)
+		value.Decode()
+
+		return value
 	}
 
 	return NewValue(nil)
@@ -262,6 +308,55 @@ func (val *Value) Append(v interface{}) *Value {
 	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
diff --git a/ethutil/value_test.go b/ethutil/value_test.go
index a100f44bc..710cbd887 100644
--- a/ethutil/value_test.go
+++ b/ethutil/value_test.go
@@ -63,3 +63,18 @@ func TestIterator(t *testing.T) {
 		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)
+	}
+}