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
|
package arg
import (
"fmt"
"reflect"
"strings"
scalar "github.com/alexflint/go-scalar"
)
// setSliceOrMap parses a sequence of strings into a slice or map. If clear is
// true then any values already in the slice or map are first removed.
func setSliceOrMap(dest reflect.Value, values []string, clear bool) error {
if !dest.CanSet() {
return fmt.Errorf("field is not writable")
}
t := dest.Type()
if t.Kind() == reflect.Ptr {
dest = dest.Elem()
t = t.Elem()
}
switch t.Kind() {
case reflect.Slice:
return setSlice(dest, values, clear)
case reflect.Map:
return setMap(dest, values, clear)
default:
return fmt.Errorf("setSliceOrMap cannot insert values into a %v", t)
}
}
// setSlice parses a sequence of strings and inserts them into a slice. If clear
// is true then any values already in the slice are removed.
func setSlice(dest reflect.Value, values []string, clear bool) error {
var ptr bool
elem := dest.Type().Elem()
if elem.Kind() == reflect.Ptr && !elem.Implements(textUnmarshalerType) {
ptr = true
elem = elem.Elem()
}
// clear the slice in case default values exist
if clear && !dest.IsNil() {
dest.SetLen(0)
}
// parse the values one-by-one
for _, s := range values {
v := reflect.New(elem)
if err := scalar.ParseValue(v.Elem(), s); err != nil {
return err
}
if !ptr {
v = v.Elem()
}
dest.Set(reflect.Append(dest, v))
}
return nil
}
// setMap parses a sequence of name=value strings and inserts them into a map.
// If clear is true then any values already in the map are removed.
func setMap(dest reflect.Value, values []string, clear bool) error {
// determine the key and value type
var keyIsPtr bool
keyType := dest.Type().Key()
if keyType.Kind() == reflect.Ptr && !keyType.Implements(textUnmarshalerType) {
keyIsPtr = true
keyType = keyType.Elem()
}
var valIsPtr bool
valType := dest.Type().Elem()
if valType.Kind() == reflect.Ptr && !valType.Implements(textUnmarshalerType) {
valIsPtr = true
valType = valType.Elem()
}
// clear the slice in case default values exist
if clear && !dest.IsNil() {
for _, k := range dest.MapKeys() {
dest.SetMapIndex(k, reflect.Value{})
}
}
// allocate the map if it is not allocated
if dest.IsNil() {
dest.Set(reflect.MakeMap(dest.Type()))
}
// parse the values one-by-one
for _, s := range values {
// split at the first equals sign
pos := strings.Index(s, "=")
if pos == -1 {
return fmt.Errorf("cannot parse %q into a map, expected format key=value", s)
}
// parse the key
k := reflect.New(keyType)
if err := scalar.ParseValue(k.Elem(), s[:pos]); err != nil {
return err
}
if !keyIsPtr {
k = k.Elem()
}
// parse the value
v := reflect.New(valType)
if err := scalar.ParseValue(v.Elem(), s[pos+1:]); err != nil {
return err
}
if !valIsPtr {
v = v.Elem()
}
// add it to the map
dest.SetMapIndex(k, v)
}
return nil
}
|
