1
// Copyright © 2014 Steve Francia <[email protected]>.
2
//
3
// Use of this source code is governed by an MIT-style
4
// license that can be found in the LICENSE file.
5

6
package cast
7

8
import (
9
	"fmt"
10
	"reflect"
11
	"strings"
12
)
13

14
// ToSliceE casts any value to a []any type.
15
func ToSliceE(i any) ([]any, error) {
16
	i, _ = indirect(i)
17

18
	var s []any
19

20
	switch v := i.(type) {
21
	case []any:
22
		// TODO: use slices.Clone
23
		return append(s, v...), nil
24
	case []map[string]any:
25
		for _, u := range v {
26
			s = append(s, u)
27
		}
28

29
		return s, nil
30
	default:
31
		return s, fmt.Errorf(errorMsg, i, i, s)
32
	}
33
}
34

35
func toSliceE[T Basic](i any) ([]T, error) {
36
	v, ok, err := toSliceEOk[T](i)
37
	if err != nil {
38
		return nil, err
39
	}
40

41
	if !ok {
42
		return nil, fmt.Errorf(errorMsg, i, i, []T{})
43
	}
44

45
	return v, nil
46
}
47

48
func toSliceEOk[T Basic](i any) ([]T, bool, error) {
49
	i, _ = indirect(i)
50
	if i == nil {
51
		return nil, true, fmt.Errorf(errorMsg, i, i, []T{})
52
	}
53

54
	switch v := i.(type) {
55
	case []T:
56
		// TODO: clone slice
57
		return v, true, nil
58
	}
59

60
	kind := reflect.TypeOf(i).Kind()
61
	switch kind {
62
	case reflect.Slice, reflect.Array:
63
		s := reflect.ValueOf(i)
64
		a := make([]T, s.Len())
65

66
		for j := 0; j < s.Len(); j++ {
67
			val, err := ToE[T](s.Index(j).Interface())
68
			if err != nil {
69
				return nil, true, fmt.Errorf(errorMsg, i, i, []T{})
70
			}
71

72
			a[j] = val
73
		}
74

75
		return a, true, nil
76
	default:
77
		return nil, false, nil
78
	}
79
}
80

81
// ToStringSliceE casts any value to a []string type.
82
func ToStringSliceE(i any) ([]string, error) {
83
	if a, ok, err := toSliceEOk[string](i); ok {
84
		if err != nil {
85
			return nil, err
86
		}
87

88
		return a, nil
89
	}
90

91
	var a []string
92

93
	switch v := i.(type) {
94
	case string:
95
		return strings.Fields(v), nil
96
	case any:
97
		str, err := ToStringE(v)
98
		if err != nil {
99
			return nil, fmt.Errorf(errorMsg, i, i, a)
100
		}
101

102
		return []string{str}, nil
103
	default:
104
		return nil, fmt.Errorf(errorMsg, i, i, a)
105
	}
106
}
107

108