blob: e91eefb15becf2fdd007fd3c992814d8c4e2cfa0 [file] [log] [blame]
Matteo Scandoloa4285862020-12-01 18:10:10 -08001package jsoniter
2
3import "fmt"
4
5// ReadNil reads a json object as nil and
6// returns whether it's a nil or not
7func (iter *Iterator) ReadNil() (ret bool) {
8 c := iter.nextToken()
9 if c == 'n' {
10 iter.skipThreeBytes('u', 'l', 'l') // null
11 return true
12 }
13 iter.unreadByte()
14 return false
15}
16
17// ReadBool reads a json object as BoolValue
18func (iter *Iterator) ReadBool() (ret bool) {
19 c := iter.nextToken()
20 if c == 't' {
21 iter.skipThreeBytes('r', 'u', 'e')
22 return true
23 }
24 if c == 'f' {
25 iter.skipFourBytes('a', 'l', 's', 'e')
26 return false
27 }
28 iter.ReportError("ReadBool", "expect t or f, but found "+string([]byte{c}))
29 return
30}
31
32// SkipAndReturnBytes skip next JSON element, and return its content as []byte.
33// The []byte can be kept, it is a copy of data.
34func (iter *Iterator) SkipAndReturnBytes() []byte {
35 iter.startCapture(iter.head)
36 iter.Skip()
37 return iter.stopCapture()
38}
39
40// SkipAndAppendBytes skips next JSON element and appends its content to
41// buffer, returning the result.
42func (iter *Iterator) SkipAndAppendBytes(buf []byte) []byte {
43 iter.startCaptureTo(buf, iter.head)
44 iter.Skip()
45 return iter.stopCapture()
46}
47
48func (iter *Iterator) startCaptureTo(buf []byte, captureStartedAt int) {
49 if iter.captured != nil {
50 panic("already in capture mode")
51 }
52 iter.captureStartedAt = captureStartedAt
53 iter.captured = buf
54}
55
56func (iter *Iterator) startCapture(captureStartedAt int) {
57 iter.startCaptureTo(make([]byte, 0, 32), captureStartedAt)
58}
59
60func (iter *Iterator) stopCapture() []byte {
61 if iter.captured == nil {
62 panic("not in capture mode")
63 }
64 captured := iter.captured
65 remaining := iter.buf[iter.captureStartedAt:iter.head]
66 iter.captureStartedAt = -1
67 iter.captured = nil
68 return append(captured, remaining...)
69}
70
71// Skip skips a json object and positions to relatively the next json object
72func (iter *Iterator) Skip() {
73 c := iter.nextToken()
74 switch c {
75 case '"':
76 iter.skipString()
77 case 'n':
78 iter.skipThreeBytes('u', 'l', 'l') // null
79 case 't':
80 iter.skipThreeBytes('r', 'u', 'e') // true
81 case 'f':
82 iter.skipFourBytes('a', 'l', 's', 'e') // false
83 case '0':
84 iter.unreadByte()
85 iter.ReadFloat32()
86 case '-', '1', '2', '3', '4', '5', '6', '7', '8', '9':
87 iter.skipNumber()
88 case '[':
89 iter.skipArray()
90 case '{':
91 iter.skipObject()
92 default:
93 iter.ReportError("Skip", fmt.Sprintf("do not know how to skip: %v", c))
94 return
95 }
96}
97
98func (iter *Iterator) skipFourBytes(b1, b2, b3, b4 byte) {
99 if iter.readByte() != b1 {
100 iter.ReportError("skipFourBytes", fmt.Sprintf("expect %s", string([]byte{b1, b2, b3, b4})))
101 return
102 }
103 if iter.readByte() != b2 {
104 iter.ReportError("skipFourBytes", fmt.Sprintf("expect %s", string([]byte{b1, b2, b3, b4})))
105 return
106 }
107 if iter.readByte() != b3 {
108 iter.ReportError("skipFourBytes", fmt.Sprintf("expect %s", string([]byte{b1, b2, b3, b4})))
109 return
110 }
111 if iter.readByte() != b4 {
112 iter.ReportError("skipFourBytes", fmt.Sprintf("expect %s", string([]byte{b1, b2, b3, b4})))
113 return
114 }
115}
116
117func (iter *Iterator) skipThreeBytes(b1, b2, b3 byte) {
118 if iter.readByte() != b1 {
119 iter.ReportError("skipThreeBytes", fmt.Sprintf("expect %s", string([]byte{b1, b2, b3})))
120 return
121 }
122 if iter.readByte() != b2 {
123 iter.ReportError("skipThreeBytes", fmt.Sprintf("expect %s", string([]byte{b1, b2, b3})))
124 return
125 }
126 if iter.readByte() != b3 {
127 iter.ReportError("skipThreeBytes", fmt.Sprintf("expect %s", string([]byte{b1, b2, b3})))
128 return
129 }
130}