Add ForkType type alias for improved type safety

- Replace [4]byte with ForkType in ForkInfoList struct
- Update constants ForkTypeDATA and ForkTypeMACR to use ForkType
- Add String() method to ForkType for better debugging
- Improve consistency with existing type patterns (FieldType, TranType)
- Clean up unused code and improve documentation

1 files changed, 24 insertions, 33 deletions

diff --git a/hotline/file_resume_data.go b/hotline/file_resume_data.go
index 5dfd2d8..80f5fe5 100644
--- a/hotline/file_resume_data.go
+++ b/hotline/file_resume_data.go
@@ -3,38 +3,54 @@ package hotline
 import (
 	"bytes"
 	"encoding/binary"
+	"fmt"
 )
 
 // FileResumeData is sent when a client or server would like to resume a transfer from an offset
 type FileResumeData struct {
 	Format       [4]byte  // "RFLT"
 	Version      [2]byte  // Always 1
-	RSVD         [34]byte // Unused
+	RSVD         [34]byte // Present in the Hotline protocol docs, but unused.  Left here for documentation purposes.
 	ForkCount    [2]byte  // Length of ForkInfoList.  Either 2 or 3 depending on whether file has a resource fork
 	ForkInfoList []ForkInfoList
+}
+
+// ForkType represents a 4-byte fork type identifier
+type ForkType [4]byte
 
-	//readOffset int // TODO
+// String returns a string representation of the fork type
+func (ft ForkType) String() string {
+	return fmt.Sprintf("%c%c%c%c", ft[0], ft[1], ft[2], ft[3])
 }
 
 type ForkInfoList struct {
-	Fork     [4]byte // "DATA" or "MACR"
-	DataSize [4]byte // offset from which to resume the transfer of data
-	RSVDA    [4]byte // Unused
-	RSVDB    [4]byte // Unused
+	Fork     ForkType // "DATA" or "MACR"
+	DataSize [4]byte  // offset from which to resume the transfer of data
+	RSVDA    [4]byte  // Present in the Hotline protocol docs, but unused.  Left here for documentation purposes.
+	RSVDB    [4]byte  // Present in the Hotline protocol docs, but unused.  Left here for documentation purposes.
 }
 
+var (
+	ForkTypeDATA = ForkType{0x44, 0x41, 0x54, 0x41} // DATA: Data fork
+	ForkTypeMACR = ForkType{0x4d, 0x41, 0x43, 0x52} // MACR: Mac resource fork
+)
+
 func NewForkInfoList(b []byte) *ForkInfoList {
 	return &ForkInfoList{
-		Fork:     [4]byte{0x44, 0x41, 0x54, 0x41},
+		Fork:     ForkTypeDATA,
 		DataSize: [4]byte{b[0], b[1], b[2], b[3]},
 		RSVDA:    [4]byte{},
 		RSVDB:    [4]byte{},
 	}
 }
 
+var (
+	FormatRFLT = [4]byte{0x52, 0x46, 0x4C, 0x54} // File resume format: "RFLT" (?)
+)
+
 func NewFileResumeData(list []ForkInfoList) *FileResumeData {
 	return &FileResumeData{
-		Format:       [4]byte{0x52, 0x46, 0x4C, 0x54}, // RFLT
+		Format:       FormatRFLT,
 		Version:      [2]byte{0, 1},
 		RSVD:         [34]byte{},
 		ForkCount:    [2]byte{0, uint8(len(list))},
@@ -42,31 +58,6 @@ func NewFileResumeData(list []ForkInfoList) *FileResumeData {
 	}
 }
 
-//
-//func (frd *FileResumeData) Read(p []byte) (int, error) {
-//	buf := slices.Concat(
-//		frd.Format[:],
-//		frd.Version[:],
-//		frd.RSVD[:],
-//		frd.ForkCount[:],
-//	)
-//	for _, fil := range frd.ForkInfoList {
-//		buf = append(buf, fil...)
-//		_ = binary.Write(&buf, binary.LittleEndian, fil)
-//	}
-//
-//	var buf bytes.Buffer
-//	_ = binary.Write(&buf, binary.LittleEndian, frd.Format)
-//	_ = binary.Write(&buf, binary.LittleEndian, frd.Version)
-//	_ = binary.Write(&buf, binary.LittleEndian, frd.RSVD)
-//	_ = binary.Write(&buf, binary.LittleEndian, frd.ForkCount)
-//	for _, fil := range frd.ForkInfoList {
-//		_ = binary.Write(&buf, binary.LittleEndian, fil)
-//	}
-//
-//	return buf.Bytes(), nil
-//}
-
 func (frd *FileResumeData) BinaryMarshal() ([]byte, error) {
 	var buf bytes.Buffer
 	_ = binary.Write(&buf, binary.LittleEndian, frd.Format)