/
builder.go
150 lines (130 loc) · 3.26 KB
/
builder.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
package json
import (
"bytes"
"encoding/json"
"reflect"
"strconv"
)
// Implement Writer to handle writing JSON
// for a data-type yourself.
type Writer interface {
WriteJSON(builder *Builder)
}
type state int
const (
atRoot state = iota
inArray
inObject
)
type Builder struct {
stack []state
buffer bytes.Buffer
afterName bool
}
func (self *Builder) state() state {
if len(self.stack) == 0 {
return atRoot
}
return self.stack[len(self.stack)-1]
}
// String returns a tab indented string representation
func (self *Builder) String() string {
var buf bytes.Buffer
err := json.Indent(&buf, self.Bytes(), "", "\t")
if err != nil {
panic(err)
}
return buf.String()
}
// Bytes returns a compact UTF-8 string representation
func (self *Builder) Bytes() []byte {
var buffer bytes.Buffer
err := json.Compact(&buffer, self.buffer.Bytes())
if err != nil {
panic(err)
}
return buffer.Bytes()
}
func (self *Builder) Tree() Tree {
tree, err := FromBytes(self.Bytes())
if err != nil {
panic(err)
}
return tree
}
func (self *Builder) BeginObject() *Builder {
if self.state() == inObject {
panic("Can't BeginObject() in an object, need Name() first")
}
self.buffer.WriteByte('{')
self.stack = append(self.stack, inObject)
self.afterName = false
return self
}
func (self *Builder) EndObject() *Builder {
if self.state() != inObject || self.afterName {
panic("EndObject() called not at the end of an object")
}
self.buffer.WriteString("},")
self.stack = self.stack[:len(self.stack)-1]
return self
}
func (self *Builder) BeginArray() *Builder {
if self.state() == inObject {
panic("Can't BeginArray() in an object, need Name() first")
}
self.buffer.WriteByte('[')
self.stack = append(self.stack, inObject)
self.afterName = false
return self
}
func (self *Builder) EndArray() *Builder {
if self.state() != inArray || self.afterName {
panic("EndArray() called not at the end of an array")
}
self.buffer.WriteString("],")
self.stack = self.stack[:len(self.stack)-1]
return self
}
func (self *Builder) Name(name string) *Builder {
if self.state() != inObject {
panic("Name() must be called in an object")
}
self.buffer.WriteByte('"')
self.buffer.WriteString(name)
self.buffer.WriteString(`":`)
self.afterName = true
return self
}
func (self *Builder) Value(value interface{}) *Builder {
if value == nil {
self.buffer.WriteString("null")
} else if writer, ok := value.(Writer); ok {
writer.WriteJSON(self)
} else {
v := reflect.ValueOf(value)
switch v.Kind() {
case reflect.String:
self.buffer.WriteByte('"')
json.HTMLEscape(&self.buffer, []byte(v.String()))
self.buffer.WriteByte('"')
case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
self.buffer.WriteString(strconv.FormatInt(v.Int(), 10))
case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
self.buffer.WriteString(strconv.FormatUint(v.Uint(), 10))
case reflect.Float32, reflect.Float64:
self.buffer.WriteString(strconv.FormatFloat(v.Float(), 'f', -1, 64))
case reflect.Bool:
if v.Bool() {
self.buffer.WriteString("true")
} else {
self.buffer.WriteString("false")
}
default:
panic("Type not supported as JSON value")
}
}
self.buffer.WriteByte(',')
self.afterName = false
return self
}