Drop support for go 1.20

[btrtrc.git] / bencode / api.go

diff --git a/bencode/api.go b/bencode/api.go
index 6c311e118047d75c2293307a89004ab28cae9b75..3c379abbf837355da04bf1cd9cd7522f0b110619 100644 (file)
--- a/bencode/api.go
+++ b/bencode/api.go
@@ -1,7 +1,6 @@
 package bencode
 
 import (
-       "bufio"
        "bytes"
        "fmt"
        "io"
@@ -42,13 +41,18 @@ func (e *UnmarshalInvalidArgError) Error() string {
 
 // Unmarshaler spotted a value that was not appropriate for a given Go value.
 type UnmarshalTypeError struct {
-       Value string
-       Type  reflect.Type
+       BencodeTypeName     string
+       UnmarshalTargetType reflect.Type
 }
 
+// This could probably be a value type, but we may already have users assuming
+// that it's passed by pointer.
 func (e *UnmarshalTypeError) Error() string {
-       return "bencode: value (" + e.Value + ") is not appropriate for type: " +
-               e.Type.String()
+       return fmt.Sprintf(
+               "can't unmarshal a bencode %v into a %v",
+               e.BencodeTypeName,
+               e.UnmarshalTargetType,
+       )
 }
 
 // Unmarshaler tried to write to an unexported (therefore unwritable) field.
@@ -111,11 +115,11 @@ type Unmarshaler interface {
        UnmarshalBencode([]byte) error
 }
 
-// Marshal the value 'v' to the bencode form, return the result as []byte and an
-// error if any.
+// Marshal the value 'v' to the bencode form, return the result as []byte and
+// an error if any.
 func Marshal(v interface{}) ([]byte, error) {
        var buf bytes.Buffer
-       e := Encoder{w: bufio.NewWriter(&buf)}
+       e := Encoder{w: &buf}
        err := e.Encode(v)
        if err != nil {
                return nil, err
@@ -129,10 +133,12 @@ func MustMarshal(v interface{}) []byte {
        return b
 }
 
-// Unmarshal the bencode value in the 'data' to a value pointed by the 'v'
-// pointer, return a non-nil error if any.
+// Unmarshal the bencode value in the 'data' to a value pointed by the 'v' pointer, return a non-nil
+// error if any. If there are trailing bytes, this results in ErrUnusedTrailingBytes, but the value
+// will be valid. It's probably more consistent to use Decoder.Decode if you want to rely on this
+// behaviour (inspired by Rust's serde here).
 func Unmarshal(data []byte, v interface{}) (err error) {
-       buf := bytes.NewBuffer(data)
+       buf := bytes.NewReader(data)
        e := Decoder{r: buf}
        err = e.Decode(v)
        if err == nil && buf.Len() != 0 {
@@ -154,5 +160,5 @@ func NewDecoder(r io.Reader) *Decoder {
 }
 
 func NewEncoder(w io.Writer) *Encoder {
-       return &Encoder{w: bufio.NewWriter(w)}
+       return &Encoder{w: w}
 }