tape: Switch StringArray over to using VILA

tape/array.go

@@ -83,7 +83,7 @@ func DecodeVILAIter(data []byte) iter.Seq[[]byte] {
 }
 
 // EncodeVILA encodes a variable item length array.
-func EncodeVILA(data []byte, items ...[]byte) ArrayPushFunc {
+func EncodeVILA(data []byte) ArrayPushFunc {
 	n := 0
 	return func(value []byte) (n_ int, err error) {
 		if n >= len(data) { return n_, fmt.Errorf("encoding VILA: %w", ErrWrongBufferLength) }
@@ -101,49 +101,47 @@ func EncodeVILA(data []byte, items ...[]byte) ArrayPushFunc {
 	}
 }
 
-// TODO: Decode, encode, size for string array needs to use VILA
+// VILASize returns the size of a variable item length array.
+func VILASize(items ...[]byte) int {
+	size := 0
+	for _, item := range items {
+		size += GBEUSize[uint](uint(len(item)))
+		size += len(item)
+	}
+	return size
+}
 
-// DecodeStringArray decodes a packed string array from the given data.
+// DecodeStringArray decodes a VILA string array from the given data.
 func DecodeStringArray[T String](data []byte) (result []T, n int, err error) {
-	for len(data) > 0 {
-		if len(data) < 2 { return nil, n, fmt.Errorf("decoding []string: %w", ErrWrongBufferLength) }
-		itemSize16, nn, _ := DecodeI16[uint16](data[:2])
-		itemSize := int(itemSize16)
+	pull := DecodeVILA(data)
+	for {
+		item, nn, err := pull()
 		n += nn
-		data = data[nn:]
-		if len(data) < itemSize { return nil, n, fmt.Errorf("decoding []string: %w", ErrWrongBufferLength) }
-		result = append(result, T(data[:itemSize]))
-		data = data[itemSize:]
-		n += itemSize
+		if err != nil { return nil, n, err }
+		result = append(result, T(item))
 	}
 	return result, n, nil
 }
 
-// EncodeStringArray encodes a packed string array into the given buffer.
+// EncodeStringArray encodes a VILA string array into the given buffer.
 func EncodeStringArray[T String](buffer []byte, value []T) (n int, err error) {
+	push := EncodeVILA(buffer)
 	for _, item := range value {
-		length, err := StringSize(item)
+		nn, err := push([]byte(item))
+		n += nn
 		if err != nil { return n, err }
-		if len(buffer) < 2 + length { return n, fmt.Errorf("encoding []string: %w", ErrWrongBufferLength) }
-		EncodeI16(buffer[:2], uint16(length))
-		buffer = buffer[2:]
-		copy(buffer, item)
-		buffer = buffer[length:]
-		n += 2 + length
 	}
-	if len(buffer) > 0 { return n, fmt.Errorf("encoding []string: %w", ErrWrongBufferLength) }
 	return n, nil
 }
 
-// StringArraySize returns the size of a packed string array. Returns 0 and an
-// error if the size is too large.
-func StringArraySize[T String](value []T) (int, error) {
-	total := 0
+// StringArraySize returns the size of a VILA string array.
+func StringArraySize[T String](value []T) int {
+	size := 0
 	for _, item := range value {
-		total += 2 + len(item)
+		size += GBEUSize[uint](uint(len(item)))
+		size += len(item)
 	}
-	if total > dataMaxSize { return 0, ErrDataTooLarge }
-	return total, nil
+	return size
 }
 
 // DecodeI8Array decodes a packed array of 8 bit integers from the given data.