path: root/rlp/encoder_example_test.go

package rlp

import (
    "fmt"
    "io"
)

type MyCoolType struct {
    Name string
    a, b uint
}

// EncodeRLP writes x as RLP list [a, b] that omits the Name field.
func (x *MyCoolType) EncodeRLP(w io.Writer) (err error) {
    // Note: the receiver can be a nil pointer. This allows you to
    // control the encoding of nil, but it also means that you have to
    // check for a nil receiver.
    if x == nil {
        err = Encode(w, []uint{0, 0})
    } else {
        err = Encode(w, []uint{x.a, x.b})
    }
    return err
}

func ExampleEncoder() {
    var t *MyCoolType // t is nil pointer to MyCoolType
    bytes, _ := EncodeToBytes(t)
    fmt.Printf("%v → %X\n", t, bytes)

    t = &MyCoolType{Name: "foobar", a: 5, b: 6}
    bytes, _ = EncodeToBytes(t)
    fmt.Printf("%v → %X\n", t, bytes)

    // Output:
    // <nil> → C28080
    // &{foobar 5 6} → C20506
}