1 package ast
2
3 import (
4 "bytes"
5 "fmt"
6 )
7
8 type Node struct {
9 Parent *Node
10 Children []*Node
11 Value interface{}
12 Kind Kind
13 }
14
15 func NewNode(k Kind, v interface{}, ch ...*Node) *Node {
16 n := &Node{
17 Kind: k,
18 Value: v,
19 }
20 for _, c := range ch {
21 Insert(n, c)
22 }
23 return n
24 }
25
26 func (a *Node) Equal(b *Node) bool {
27 if a.Kind != b.Kind {
28 return false
29 }
30 if a.Value != b.Value {
31 return false
32 }
33 if len(a.Children) != len(b.Children) {
34 return false
35 }
36 for i, c := range a.Children {
37 if !c.Equal(b.Children[i]) {
38 return false
39 }
40 }
41 return true
42 }
43
44 func (a *Node) String() string {
45 var buf bytes.Buffer
46 buf.WriteString(a.Kind.String())
47 if a.Value != nil {
48 buf.WriteString(" =")
49 buf.WriteString(fmt.Sprintf("%v", a.Value))
50 }
51 if len(a.Children) > 0 {
52 buf.WriteString(" [")
53 for i, c := range a.Children {
54 if i > 0 {
55 buf.WriteString(", ")
56 }
57 buf.WriteString(c.String())
58 }
59 buf.WriteString("]")
60 }
61 return buf.String()
62 }
63
64 func Insert(parent *Node, children ...*Node) {
65 parent.Children = append(parent.Children, children...)
66 for _, ch := range children {
67 ch.Parent = parent
68 }
69 }
70
71 type List struct {
72 Not bool
73 Chars string
74 }
75
76 type Range struct {
77 Not bool
78 Lo, Hi rune
79 }
80
81 type Text struct {
82 Text string
83 }
84
85 type Kind int
86
87 const (
88 KindNothing Kind = iota
89 KindPattern
90 KindList
91 KindRange
92 KindText
93 KindAny
94 KindSuper
95 KindSingle
96 KindAnyOf
97 )
98
99 func (k Kind) String() string {
100 switch k {
101 case KindNothing:
102 return "Nothing"
103 case KindPattern:
104 return "Pattern"
105 case KindList:
106 return "List"
107 case KindRange:
108 return "Range"
109 case KindText:
110 return "Text"
111 case KindAny:
112 return "Any"
113 case KindSuper:
114 return "Super"
115 case KindSingle:
116 return "Single"
117 case KindAnyOf:
118 return "AnyOf"
119 default:
120 return ""
121 }
122 }
123
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