1 files changed, 257 insertions, 0 deletions
diff --git a/pkg/jsonpath/node.go b/pkg/jsonpath/node.go
new file mode 100644
index 0000000..baef6c5
--- /dev/null
+++ b/pkg/jsonpath/node.go
@@ -0,0 +1,257 @@
+// This file is copied from the Kubernetes jsonpath implementation.
+
+/*
+Copyright 2015 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package jsonpath
+
+import "fmt"
+
+// NodeType identifies the type of a parse tree node.
+type NodeType int
+
+// Type returns itself and provides an easy default implementation
+func (t NodeType) Type() NodeType {
+	return t
+}
+
+func (t NodeType) String() string {
+	return NodeTypeName[t]
+}
+
+const (
+	NodeText NodeType = iota
+	NodeArray
+	NodeList
+	NodeField
+	NodeIdentifier
+	NodeFilter
+	NodeInt
+	NodeFloat
+	NodeWildcard
+	NodeRecursive
+	NodeUnion
+	NodeBool
+)
+
+var NodeTypeName = map[NodeType]string{
+	NodeText:       "NodeText",
+	NodeArray:      "NodeArray",
+	NodeList:       "NodeList",
+	NodeField:      "NodeField",
+	NodeIdentifier: "NodeIdentifier",
+	NodeFilter:     "NodeFilter",
+	NodeInt:        "NodeInt",
+	NodeFloat:      "NodeFloat",
+	NodeWildcard:   "NodeWildcard",
+	NodeRecursive:  "NodeRecursive",
+	NodeUnion:      "NodeUnion",
+	NodeBool:       "NodeBool",
+}
+
+type Node interface {
+	Type() NodeType
+	String() string
+}
+
+// ListNode holds a sequence of nodes.
+type ListNode struct {
+	NodeType
+	Nodes []Node // The element nodes in lexical order.
+}
+
+func newList() *ListNode {
+	return &ListNode{NodeType: NodeList}
+}
+
+func (l *ListNode) append(n Node) {
+	l.Nodes = append(l.Nodes, n)
+}
+
+func (l *ListNode) String() string {
+	return fmt.Sprintf("%s", l.Type())
+}
+
+// TextNode holds plain text.
+type TextNode struct {
+	NodeType
+	Text string // The text; may span newlines.
+}
+
+func newText(text string) *TextNode {
+	return &TextNode{NodeType: NodeText, Text: text}
+}
+
+func (t *TextNode) String() string {
+	return fmt.Sprintf("%s: %s", t.Type(), t.Text)
+}
+
+// FieldNode holds field of struct
+type FieldNode struct {
+	NodeType
+	Value string
+}
+
+func newField(value string) *FieldNode {
+	return &FieldNode{NodeType: NodeField, Value: value}
+}
+
+func (f *FieldNode) String() string {
+	return fmt.Sprintf("%s: %s", f.Type(), f.Value)
+}
+
+// IdentifierNode holds an identifier
+type IdentifierNode struct {
+	NodeType
+	Name string
+}
+
+func newIdentifier(value string) *IdentifierNode {
+	return &IdentifierNode{
+		NodeType: NodeIdentifier,
+		Name:     value,
+	}
+}
+
+func (f *IdentifierNode) String() string {
+	return fmt.Sprintf("%s: %s", f.Type(), f.Name)
+}
+
+// ParamsEntry holds param information for ArrayNode
+type ParamsEntry struct {
+	Value int
+	Known bool // whether the value is known when parse it
+}
+
+// ArrayNode holds start, end, step information for array index selection
+type ArrayNode struct {
+	NodeType
+	Params [3]ParamsEntry // start, end, step
+}
+
+func newArray(params [3]ParamsEntry) *ArrayNode {
+	return &ArrayNode{
+		NodeType: NodeArray,
+		Params:   params,
+	}
+}
+
+func (a *ArrayNode) String() string {
+	return fmt.Sprintf("%s: %v", a.Type(), a.Params)
+}
+
+// FilterNode holds operand and operator information for filter
+type FilterNode struct {
+	NodeType
+	Left     *ListNode
+	Right    *ListNode
+	Operator string
+}
+
+func newFilter(left, right *ListNode, operator string) *FilterNode {
+	return &FilterNode{
+		NodeType: NodeFilter,
+		Left:     left,
+		Right:    right,
+		Operator: operator,
+	}
+}
+
+func (f *FilterNode) String() string {
+	return fmt.Sprintf("%s: %s %s %s", f.Type(), f.Left, f.Operator, f.Right)
+}
+
+// IntNode holds integer value
+type IntNode struct {
+	NodeType
+	Value int
+}
+
+func newInt(num int) *IntNode {
+	return &IntNode{NodeType: NodeInt, Value: num}
+}
+
+func (i *IntNode) String() string {
+	return fmt.Sprintf("%s: %d", i.Type(), i.Value)
+}
+
+// FloatNode holds float value
+type FloatNode struct {
+	NodeType
+	Value float64
+}
+
+func newFloat(num float64) *FloatNode {
+	return &FloatNode{NodeType: NodeFloat, Value: num}
+}
+
+func (i *FloatNode) String() string {
+	return fmt.Sprintf("%s: %f", i.Type(), i.Value)
+}
+
+// WildcardNode means a wildcard
+type WildcardNode struct {
+	NodeType
+}
+
+func newWildcard() *WildcardNode {
+	return &WildcardNode{NodeType: NodeWildcard}
+}
+
+func (i *WildcardNode) String() string {
+	return fmt.Sprintf("%s", i.Type())
+}
+
+// RecursiveNode means a recursive descent operator
+type RecursiveNode struct {
+	NodeType
+}
+
+func newRecursive() *RecursiveNode {
+	return &RecursiveNode{NodeType: NodeRecursive}
+}
+
+func (r *RecursiveNode) String() string {
+	return fmt.Sprintf("%s", r.Type())
+}
+
+// UnionNode is union of ListNode
+type UnionNode struct {
+	NodeType
+	Nodes []*ListNode
+}
+
+func newUnion(nodes []*ListNode) *UnionNode {
+	return &UnionNode{NodeType: NodeUnion, Nodes: nodes}
+}
+
+func (u *UnionNode) String() string {
+	return fmt.Sprintf("%s", u.Type())
+}
+
+// BoolNode holds bool value
+type BoolNode struct {
+	NodeType
+	Value bool
+}
+
+func newBool(value bool) *BoolNode {
+	return &BoolNode{NodeType: NodeBool, Value: value}
+}
+
+func (b *BoolNode) String() string {
+	return fmt.Sprintf("%s: %t", b.Type(), b.Value)
+}