package api import ( "encoding/json" "github.com/ethereum/go-ethereum/rpc/shared" ) type Sha3Args struct { Data string } func (args *Sha3Args) UnmarshalJSON(b []byte) (err error) { var obj []interface{} if err := json.Unmarshal(b, &obj); err != nil { return shared.NewDecodeParamError(err.Error()) } if len(obj) < 1 { return shared.NewInsufficientParamsError(len(obj), 1) } argstr, ok := obj[0].(string) if !ok { return shared.NewInvalidTypeError("data", "is not a string") } args.Data = argstr return nil }