move error definitions to doc.go (#158)

Author: gballet

doc.go

@@ -0,0 +1,44 @@
+// This is free and unencumbered software released into the public domain.
+//
+// Anyone is free to copy, modify, publish, use, compile, sell, or
+// distribute this software, either in source code form or as a compiled
+// binary, for any purpose, commercial or non-commercial, and by any
+// means.
+//
+// In jurisdictions that recognize copyright laws, the author or authors
+// of this software dedicate any and all copyright interest in the
+// software to the public domain. We make this dedication for the benefit
+// of the public at large and to the detriment of our heirs and
+// successors. We intend this dedication to be an overt act of
+// relinquishment in perpetuity of all present and future rights to this
+// software under copyright law.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+// IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR
+// OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+// ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+// OTHER DEALINGS IN THE SOFTWARE.
+//
+// For more information, please refer to <https://unlicense.org>
+
+package verkle
+
+import "errors"
+
+var (
+	errInsertIntoHash          = errors.New("trying to insert into hashed node")
+	errDeleteNonExistent       = errors.New("trying to delete non-existent leaf")
+	errDeleteHash              = errors.New("trying to delete from a hashed subtree")
+	errReadFromInvalid         = errors.New("trying to read from an invalid child")
+	errSerializeHashedNode     = errors.New("trying to serialized a hashed node")
+	errNotSupportedInStateless = errors.New("not implemented in stateless")
+)
+
+const (
+	// Extension status
+	extStatusAbsentEmpty = byte(iota) // missing child node along the path
+	extStatusAbsentOther              // path led to a node with a different stem
+	extStatusPresent                  // stem was present
+)

stateless.go

@@ -44,7 +44,7 @@ type StatelessNode struct {
 	stem []byte
 
 	// node depth in the tree, in bits
-	depth int
+	depth byte
 
 	// child count, used for the special case in
 	// commitment calculations.
@@ -60,8 +60,6 @@ type StatelessNode struct {
 	committer Committer
 }
 
-var errNotSupportedInStateless = errors.New("not implemented in stateless")
-
 func NewStateless() *StatelessNode {
 	return &StatelessNode{
 		children:   make(map[byte]*StatelessNode),
@@ -274,7 +272,7 @@ func (n *StatelessNode) ComputeCommitment() *Fr {
 		count1, count2 := 0, 0
 		var poly, c1poly, c2poly [256]Fr
 		poly[0].SetUint64(1)
-		fromBytes(&poly[1], n.stem)
+		FromBytes(&poly[1], n.stem)
 
 		for idx, val := range n.values {
 			if idx < 128 {
@@ -309,12 +307,12 @@ func (n *StatelessNode) ComputeCommitment() *Fr {
 	return n.hash
 }
 
-func (*StatelessNode) GetCommitmentsAlongPath([]byte) *ProofElements {
+func (*StatelessNode) GetCommitmentsAlongPath([]byte) (*ProofElements, byte, []byte) {
 	panic("not supported in stateless mode")
 }
 
 func (*StatelessNode) Serialize() ([]byte, error) {
-	return nil, errors.New("not supported")
+	return nil, errNotSupportedInStateless
 }
 
 func (n *StatelessNode) Copy() VerkleNode {

tree.go

@@ -131,21 +131,6 @@ const (
 	leafRLPType     byte = 2
 )
 
-var (
-	errInsertIntoHash      = errors.New("trying to insert into hashed node")
-	errDeleteNonExistent   = errors.New("trying to delete non-existent leaf")
-	errDeleteHash          = errors.New("trying to delete from a hashed subtree")
-	errReadFromInvalid     = errors.New("trying to read from an invalid child")
-	errSerializeHashedNode = errors.New("trying to serialized a hashed node")
-)
-
-const (
-	// Extension status
-	extStatusAbsentEmpty = byte(iota) // missing child node along the path
-	extStatusAbsentOther              // path led to a node with a different stem
-	extStatusPresent                  // stem was present
-)
-
 type (
 	// Represents an internal node at any level
 	InternalNode struct {
@@ -475,7 +460,7 @@ func (n *InternalNode) ComputeCommitment() *Fr {
 	// Special cases of a node with no children: either it's
 	// an empty root, or it's an invalid node.
 	if n.count == 0 {
-		if n.depth != byte(0) {
+		if n.depth != 0 {
 			panic("internal node should be empty node")
 		}