tape/types.go

@@ -3,6 +3,8 @@ package tape
 
 import "fmt"
 
+// encoding and decoding functions must not make any allocations
+
 const dataMaxSize = 0xFFFF
 const uint16Max = 0xFFFF
 
@@ -119,12 +121,12 @@ func DecodeGBEU[T UInt](data []byte) (T, error) {
 }
 
 // EncodeGBEU encodes an 8 to 64 bit growing integer into a given buffer.
-func EncodeGBEU[T UInt]	(buffer []byte, value T) (error) {
+func EncodeGBEU[T UInt]	(buffer []byte, value T) (n int, err error) {
 	window := (GBEUSize(value) - 1) * 7
 	
 	index := 0
 	for window >= 0 {
-		if index >= len(buffer) { return fmt.Errorf("encoding GBEU: %w", ErrWrongBufferLength) }
+		if index >= len(buffer) { return index, fmt.Errorf("encoding GBEU: %w", ErrWrongBufferLength) }
 		
 		chunk := uint8(value >> window) & 0x7F
 		if window > 0 {