Encoding Package - Go Implementation

Import: github.com/haivivi/giztoy/pkg/encoding

Types

StdBase64Data

type StdBase64Data []byte

A byte slice that serializes to/from standard Base64 in JSON.

Methods:

Method	Signature	Description
`MarshalJSON`	`() ([]byte, error)`	Encode to JSON Base64 string
`UnmarshalJSON`	`(data []byte) error`	Decode from JSON Base64 string
`String`	`() string`	Return Base64-encoded string

HexData

type HexData []byte

A byte slice that serializes to/from hexadecimal in JSON.

Methods:

Method	Signature	Description
`MarshalJSON`	`() ([]byte, error)`	Encode to JSON hex string
`UnmarshalJSON`	`(data []byte) error`	Decode from JSON hex string
`String`	`() string`	Return hex-encoded string

Usage

In Struct Fields

type Message struct {
    ID      string        `json:"id"`
    Payload StdBase64Data `json:"payload"`
    Hash    HexData       `json:"hash"`
}

msg := Message{
    ID:      "msg-123",
    Payload: StdBase64Data([]byte("hello world")),
    Hash:    HexData([]byte{0xab, 0xcd, 0xef}),
}

// Marshals to:
// {"id":"msg-123","payload":"aGVsbG8gd29ybGQ=","hash":"abcdef"}
data, _ := json.Marshal(msg)

Standalone Encoding

// Base64
data := StdBase64Data([]byte("hello"))
fmt.Println(data.String())  // "aGVsbG8="

// Hex
hash := HexData([]byte{0xde, 0xad})
fmt.Println(hash.String())  // "dead"

Null Handling

var data StdBase64Data
json.Unmarshal([]byte(`null`), &data)  // data is nil

json.Unmarshal([]byte(`""`), &data)    // data is []byte{}

Implementation Details

UnmarshalJSON Logic

Both types handle multiple JSON input types:

func (b *StdBase64Data) UnmarshalJSON(data []byte) error {
    switch data[0] {
    case 'n':  // null
        return nil
    case '"':  // string
        // decode Base64
    default:
        return error
    }
}

Direct Slice Alias

Go implementation uses direct type alias type StdBase64Data []byte, which means:

No wrapper overhead
Can be cast directly to/from []byte
Shares underlying array with original slice

Dependencies

encoding/base64 (stdlib)
encoding/hex (stdlib)

Giztoy Documentation