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| author | Mitja Felicijan <mitja.felicijan@gmail.com> | 2024-10-25 00:47:47 +0200 |
|---|---|---|
| committer | Mitja Felicijan <mitja.felicijan@gmail.com> | 2024-10-25 00:47:47 +0200 |
| commit | c6cc0108ca7738023b45e0eeac0fa2390532dd93 (patch) | |
| tree | 36890e6cd3091bbab8efbe686cc56f467f645bfd /vendor/github.com/alexflint/go-scalar/scalar.go | |
| parent | 0130404a1dc663d4aa68d780c9bcb23a4243e68d (diff) | |
| download | jbmafp-master.tar.gz | |
Diffstat (limited to 'vendor/github.com/alexflint/go-scalar/scalar.go')
| -rw-r--r-- | vendor/github.com/alexflint/go-scalar/scalar.go | 162 |
1 files changed, 162 insertions, 0 deletions
diff --git a/vendor/github.com/alexflint/go-scalar/scalar.go b/vendor/github.com/alexflint/go-scalar/scalar.go new file mode 100644 index 0000000..421bfac --- /dev/null +++ b/vendor/github.com/alexflint/go-scalar/scalar.go @@ -0,0 +1,162 @@ +// Package scalar parses strings into values of scalar type. + +package scalar + +import ( + "encoding" + "errors" + "fmt" + "net" + "net/mail" + "net/url" + "reflect" + "strconv" + "time" +) + +// The reflected form of some special types +var ( + textUnmarshalerType = reflect.TypeOf([]encoding.TextUnmarshaler{}).Elem() + durationType = reflect.TypeOf(time.Duration(0)) + mailAddressType = reflect.TypeOf(mail.Address{}) + macType = reflect.TypeOf(net.HardwareAddr{}) + urlType = reflect.TypeOf(url.URL{}) +) + +var ( + errNotSettable = errors.New("value is not settable") + errPtrNotSettable = errors.New("value is a nil pointer and is not settable") +) + +// Parse assigns a value to v by parsing s. +func Parse(dest interface{}, s string) error { + return ParseValue(reflect.ValueOf(dest), s) +} + +// ParseValue assigns a value to v by parsing s. +func ParseValue(v reflect.Value, s string) error { + // If we have a nil pointer then allocate a new object + if v.Kind() == reflect.Ptr && v.IsNil() { + if !v.CanSet() { + return errPtrNotSettable + } + + v.Set(reflect.New(v.Type().Elem())) + } + + // If it implements encoding.TextUnmarshaler then use that + if scalar, ok := v.Interface().(encoding.TextUnmarshaler); ok { + return scalar.UnmarshalText([]byte(s)) + } + // If it's a value instead of a pointer, check that we can unmarshal it + // via TextUnmarshaler as well + if v.CanAddr() { + if scalar, ok := v.Addr().Interface().(encoding.TextUnmarshaler); ok { + return scalar.UnmarshalText([]byte(s)) + } + } + + // If we have a pointer then dereference it + if v.Kind() == reflect.Ptr { + v = v.Elem() + } + + if !v.CanSet() { + return errNotSettable + } + + // Switch on concrete type + switch scalar := v.Interface(); scalar.(type) { + case time.Duration: + duration, err := time.ParseDuration(s) + if err != nil { + return err + } + v.Set(reflect.ValueOf(duration)) + return nil + case mail.Address: + addr, err := mail.ParseAddress(s) + if err != nil { + return err + } + v.Set(reflect.ValueOf(*addr)) + return nil + case net.HardwareAddr: + ip, err := net.ParseMAC(s) + if err != nil { + return err + } + v.Set(reflect.ValueOf(ip)) + return nil + case url.URL: + url, err := url.Parse(s) + if err != nil { + return err + } + v.Set(reflect.ValueOf(*url)) + return nil + } + + // Switch on kind so that we can handle derived types + switch v.Kind() { + case reflect.String: + v.SetString(s) + case reflect.Bool: + x, err := strconv.ParseBool(s) + if err != nil { + return err + } + v.SetBool(x) + case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64: + x, err := strconv.ParseInt(s, 10, v.Type().Bits()) + if err != nil { + return err + } + v.SetInt(x) + case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr: + x, err := strconv.ParseUint(s, 10, v.Type().Bits()) + if err != nil { + return err + } + v.SetUint(x) + case reflect.Float32, reflect.Float64: + x, err := strconv.ParseFloat(s, v.Type().Bits()) + if err != nil { + return err + } + v.SetFloat(x) + default: + return fmt.Errorf("cannot parse into %v", v.Type()) + } + return nil +} + +// CanParse returns true if the type can be parsed from a string. +func CanParse(t reflect.Type) bool { + // If it implements encoding.TextUnmarshaler then use that + if t.Implements(textUnmarshalerType) || reflect.PtrTo(t).Implements(textUnmarshalerType) { + return true + } + + // If we have a pointer then dereference it + if t.Kind() == reflect.Ptr { + t = t.Elem() + } + + // Check for other special types + switch t { + case durationType, mailAddressType, macType, urlType: + return true + } + + // Fall back to checking the kind + switch t.Kind() { + case reflect.Bool: + return true + case reflect.String, reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64, + reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr, + reflect.Float32, reflect.Float64: + return true + } + return false +} |
