// checkDecodeFromJSON decodes from s guided by exp. exp drives the
// Stream by invoking decoding operations (Uint, Big, List, ...) based
// on the type of each value. The value decoded from the RLP stream
// must match the JSON value.
func checkDecodeFromJSON(s *rlp.Stream, exp interface{}) error {
switch exp := exp.(type) {
case uint64:
i, err := s.Uint()
if err != nil {
return addStack("Uint", exp, err)
}
if i != exp {
return addStack("Uint", exp, fmt.Errorf("result mismatch: got %d", i))
}
case *big.Int:
big := new(big.Int)
if err := s.Decode(&big); err != nil {
return addStack("Big", exp, err)
}
if big.Cmp(exp) != 0 {
return addStack("Big", exp, fmt.Errorf("result mismatch: got %d", big))
}
case []byte:
b, err := s.Bytes()
if err != nil {
return addStack("Bytes", exp, err)
}
if !bytes.Equal(b, exp) {
return addStack("Bytes", exp, fmt.Errorf("result mismatch: got %x", b))
}
case []interface{}:
if _, err := s.List(); err != nil {
return addStack("List", exp, err)
}
for i, v := range exp {
if err := checkDecodeFromJSON(s, v); err != nil {
return addStack(fmt.Sprintf("[%d]", i), exp, err)
}
}
if err := s.ListEnd(); err != nil {
return addStack("ListEnd", exp, err)
}
default:
panic(fmt.Errorf("unhandled type: %T", exp))
}
return nil
}
