rlp

Encodes and decodes values using Recursive Length Prefix (RLP) encoding, the serialization format used in Ethereum.

Import

import "github.com/ChefBingbong/viem-go/utils/encoding"

Usage

import "github.com/ChefBingbong/viem-go/utils/encoding"

// Encode hex string to RLP
encoded, _ := encoding.ToRlp("0x123456789").Hex()
// "0x850123456789"

// Encode byte array to RLP
encoded, _ := encoding.ToRlp([]byte{1, 2, 3, 4, 5, 6, 7, 8, 9}).Hex()
// "0x89010203040506070809"

// Encode list to RLP
encoded, _ := encoding.ToRlp([]any{
  "0x7f",
  "0x7f",
  "0x8081e8",
}).Hex()
// "0xc67f7f838081e8"

// Decode RLP hex string
decoded, _ := encoding.FromRlp("0x850123456789")
result, _ := decoded.Hex()
// "0x123456789"

// Decode RLP list
decoded, _ := encoding.FromRlp("0xc67f7f838081e8")
result, _ := decoded.Hex()
// []any{"0x7f", "0x7f", "0x8081e8"}

Returns

• Type: ([]byte, error) for Bytes(), (string, error) for Hex(), (any, error) for decoder methods

The RLP-encoded or decoded value.

Parameters

value (required for encoding)

• Type: any (supports []byte, string (hex), []any, encoding.RecursiveBytes)

The value to RLP encode.

// Encode hex string
encoded, _ := encoding.ToRlp("0x123456789").Hex()
// "0x850123456789"

// Encode list
encoded, _ := encoding.ToRlp([]any{"0x7f", "0x7f"}).Hex()
// "0xc27f7f"

data (required for decoding)

• Type: []byte or string (hex)

The RLP-encoded data to decode.

// Decode from hex string
decoded, _ := encoding.FromRlp("0x850123456789")
result, _ := decoded.Hex()
// "0x123456789"

// Decode from bytes
decoded, _ := encoding.FromRlp([]byte{0x85, 0x01, 0x23, 0x45, 0x67, 0x89})
result, _ := decoded.Bytes()
// []byte{0x01, 0x23, 0x45, 0x67, 0x89}

Encoding Methods

Hex()

Encodes to RLP and returns a hex string:

encoded, _ := encoding.ToRlp("0x123456789").Hex()
// "0x850123456789"

Bytes()

Encodes to RLP and returns bytes:

encoded, _ := encoding.ToRlp("0x123456789").Bytes()
// []byte{0x85, 0x01, 0x23, 0x45, 0x67, 0x89}

Decoding Methods

Hex()

Decodes RLP and returns the result as recursive hex strings:

decoded, _ := encoding.FromRlp("0xc67f7f838081e8")
result, _ := decoded.Hex()
// []any{"0x7f", "0x7f", "0x8081e8"}

Bytes()

Decodes RLP and returns the result as recursive bytes:

decoded, _ := encoding.FromRlp("0x850123456789")
result, _ := decoded.Bytes()
// []byte{0x01, 0x23, 0x45, 0x67, 0x89}

Standalone Functions

RlpEncode

Encodes data to RLP bytes:

encoded, _ := encoding.RlpEncode("0x123456789")
// []byte{0x85, 0x01, 0x23, 0x45, 0x67, 0x89}

RlpEncodeToHex

Encodes data to RLP hex string:

encoded, _ := encoding.RlpEncodeToHex("0x123456789")
// "0x850123456789"

RlpDecode

Decodes RLP bytes:

decoded, _ := encoding.RlpDecode([]byte{0x85, 0x01, 0x23, 0x45, 0x67, 0x89})
// []byte{0x01, 0x23, 0x45, 0x67, 0x89}

RlpDecodeHex

Decodes RLP hex string:

decoded, _ := encoding.RlpDecodeHex("0x850123456789")
// []byte{0x01, 0x23, 0x45, 0x67, 0x89}

RLP Encoding Rules

• Single bytes < 0x80 encode as themselves
• Short strings (1-55 bytes) encode as 0x80 + length followed by bytes
• Long strings (>55 bytes) encode as 0xb7 + length_of_length followed by length and bytes
• Short lists (total length ≤55 bytes) encode as 0xc0 + length followed by items
• Long lists (>55 bytes total) encode as 0xf7 + length_of_length followed by length and items