remove error on NewBoolean

Expose underlying with Getter on Boolean StackItem
Add Equals method for ByteArray

pkg/vm/stack/Int.go

@@ -85,7 +85,7 @@ func (i *Int) ByteArray() (*ByteArray, error) {
 // to convert an Integer into a Boolean StackItem
 func (i *Int) Boolean() (*Boolean, error) {
 	boolean := (i.val.Int64() != 0)
-	return NewBoolean(boolean)
+	return NewBoolean(boolean), nil
 }
 
 //Value returns the underlying big.Int

pkg/vm/stack/boolean.go

@@ -7,11 +7,11 @@ type Boolean struct {
 }
 
 //NewBoolean returns a new boolean stack item
-func NewBoolean(val bool) (*Boolean, error) {
+func NewBoolean(val bool) *Boolean {
 	return &Boolean{
 		&abstractItem{},
 		val,
-	}, nil
+	}
 }
 
 // Boolean overrides the default implementation
@@ -19,3 +19,8 @@ func NewBoolean(val bool) (*Boolean, error) {
 func (b *Boolean) Boolean() (*Boolean, error) {
 	return b, nil
 }
+
+// Value returns the underlying boolean value
+func (b *Boolean) Value() bool {
+	return b.val
+}

pkg/vm/stack/bytearray.go

@@ -1,6 +1,7 @@
 package stack
 
 import (
+	"bytes"
 	"errors"
 	"math/big"
 	"strconv"
@@ -26,6 +27,15 @@ func (ba *ByteArray) ByteArray() (*ByteArray, error) {
 	return ba, nil
 }
 
+//Equals returns true, if two bytearrays are equal
+func (ba *ByteArray) Equals(other *ByteArray) *Boolean {
+	// If either are nil, return false
+	if ba == nil || other == nil {
+		return NewBoolean(false)
+	}
+	return NewBoolean(bytes.Equal(ba.val, other.val))
+}
+
 //Integer overrides the default Integer method to convert an
 // ByteArray Into an integer
 func (ba *ByteArray) Integer() (*Int, error) {
@@ -41,7 +51,7 @@ func (ba *ByteArray) Boolean() (*Boolean, error) {
 	if err != nil {
 		return nil, errors.New("cannot convert byte array to a boolean")
 	}
-	return NewBoolean(boolean)
+	return NewBoolean(boolean), nil
 }
 
 // XXX: move this into a pkg/util/slice folder