-
Notifications
You must be signed in to change notification settings - Fork 0
/
assignstring.go
204 lines (174 loc) · 4.83 KB
/
assignstring.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
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
package command
import (
"encoding"
"encoding/json"
"fmt"
"reflect"
"strings"
"time"
"github.com/domonda/go-types/nullable"
"github.com/ungerik/go-fs"
)
func assignString(destVal reflect.Value, sourceStr string) (err error) {
defer func() {
if err != nil {
err = fmt.Errorf("assignString(%s, %q): %w", destVal.Type(), sourceStr, err)
}
}()
destPtr := destVal.Addr().Interface()
switch dest := destPtr.(type) {
case *string:
*dest = sourceStr
return nil
case *time.Time:
for _, format := range TimeFormats {
t, err := time.ParseInLocation(format, sourceStr, time.Local)
if err == nil {
*dest = t
return nil
}
}
return fmt.Errorf("can't parse %q as time.Time using formats %#v", sourceStr, TimeFormats)
case *nullable.Time:
for _, format := range TimeFormats {
t, err := nullable.TimeParseInLocation(format, sourceStr, time.Local)
if err == nil {
*dest = t
return nil
}
}
return fmt.Errorf("can't parse %q as nullable.Time using formats %#v", sourceStr, TimeFormats)
case *time.Duration:
duration, err := time.ParseDuration(sourceStr)
if err != nil {
return fmt.Errorf("can't parse %q as time.Duration because of: %w", sourceStr, err)
}
*dest = duration
return nil
case encoding.TextUnmarshaler:
return dest.UnmarshalText([]byte(sourceStr))
case *fs.FileReader:
*dest = fs.File(sourceStr)
return nil
case json.Unmarshaler:
return dest.UnmarshalJSON([]byte(sourceStr))
case *map[string]interface{}:
return json.Unmarshal([]byte(sourceStr), dest)
case *[]interface{}:
return json.Unmarshal([]byte(sourceStr), dest)
case *[]byte:
*dest = []byte(sourceStr)
return nil
}
switch destVal.Kind() {
case reflect.String:
destVal.Set(reflect.ValueOf(sourceStr).Convert(destVal.Type()))
return nil
case reflect.Struct:
// JSON might not be the best format for command line arguments,
// but it could have also come from a HTTP request body or other sources
return json.Unmarshal([]byte(sourceStr), destPtr)
case reflect.Ptr:
ptr := destVal
if sourceStr != "nil" {
if ptr.IsNil() {
ptr = reflect.New(destVal.Type().Elem())
}
err := assignString(ptr.Elem(), sourceStr)
if err != nil {
return err
}
destVal.Set(ptr)
}
return nil
case reflect.Slice:
if !strings.HasPrefix(sourceStr, "[") {
return fmt.Errorf("slice value %q does not begin with '['", sourceStr)
}
if !strings.HasSuffix(sourceStr, "]") {
return fmt.Errorf("slice value %q does not end with ']'", sourceStr)
}
// elemSourceStrings := strings.Split(sourceStr[1:len(sourceStr)-1], ",")
sourceFields, err := sliceLiteralFields(sourceStr)
if err != nil {
return err
}
count := len(sourceFields)
destVal.Set(reflect.MakeSlice(destVal.Type(), count, count))
for i := 0; i < count; i++ {
err := assignString(destVal.Index(i), sourceFields[i])
if err != nil {
return err
}
}
return nil
case reflect.Array:
if !strings.HasPrefix(sourceStr, "[") {
return fmt.Errorf("array value %q does not begin with '['", sourceStr)
}
if !strings.HasSuffix(sourceStr, "]") {
return fmt.Errorf("array value %q does not end with ']'", sourceStr)
}
// elemSourceStrings := strings.Split(sourceStr[1:len(sourceStr)-1], ",")
sourceFields, err := sliceLiteralFields(sourceStr)
if err != nil {
return err
}
count := len(sourceFields)
if count != destVal.Len() {
return fmt.Errorf("array value %q needs to have %d elements, but has %d", sourceStr, destVal.Len(), count)
}
for i := 0; i < count; i++ {
err := assignString(destVal.Index(i), sourceFields[i])
if err != nil {
return err
}
}
return nil
case reflect.Func:
// We can't assign a string to a function, it's OK to ignore it
return nil
}
// If all else fails, use fmt scanning
// for generic type conversation from string
_, err = fmt.Sscan(sourceStr, destPtr)
return err
}
func sliceLiteralFields(sourceStr string) (fields []string, err error) {
if !strings.HasPrefix(sourceStr, "[") {
return nil, fmt.Errorf("slice value %q does not begin with '['", sourceStr)
}
if !strings.HasSuffix(sourceStr, "]") {
return nil, fmt.Errorf("slice value %q does not end with ']'", sourceStr)
}
objectDepth := 0
bracketDepth := 0
begin := 1
for i, r := range sourceStr {
switch r {
case '{':
objectDepth++
case '}':
objectDepth--
if objectDepth < 0 {
return nil, fmt.Errorf("slice value %q has too many '}'", sourceStr)
}
case '[':
bracketDepth++
case ']':
bracketDepth--
if bracketDepth < 0 {
return nil, fmt.Errorf("slice value %q has too many ']'", sourceStr)
}
if objectDepth == 0 && bracketDepth == 0 && i-begin > 0 {
fields = append(fields, sourceStr[begin:i])
}
case ',':
if objectDepth == 0 && bracketDepth == 1 {
fields = append(fields, sourceStr[begin:i])
begin = i + 1
}
}
}
return fields, nil
}