From 2e48a42fb9b9e946958810cfbb90ae85bee997e4 Mon Sep 17 00:00:00 2001
From: Luke Shumaker <lukeshu@lukeshu.com>
Date: Mon, 30 Jan 2023 20:46:07 -0700
Subject: decode: Remove unnecessary scanner struct members

---
 decode_scan.go | 30 ++++++++++++------------------
 1 file changed, 12 insertions(+), 18 deletions(-)

diff --git a/decode_scan.go b/decode_scan.go
index b9a5ea8..387fcea 100644
--- a/decode_scan.go
+++ b/decode_scan.go
@@ -35,28 +35,24 @@ type runeTypeScannerImpl struct {
 
 	inner io.RuneScanner // initialized by constructor
 
-	initialized bool
-
 	parser internal.Parser // initialized by constructor
 	offset int64
 
-	repeat  bool
-	stuck   bool
-	rRune   rune
-	rRuneOK bool
-	rSize   int
-	rType   internal.RuneType
-	rErr    error
+	initialized bool
+	repeat      bool
+
+	rRune rune
+	rSize int
+	rType internal.RuneType
+	rErr  error
 }
 
 var _ runeTypeScanner = (*runeTypeScannerImpl)(nil)
 
 func (sc *runeTypeScannerImpl) Reset() {
 	sc.parser.Reset()
-	unread := sc.stuck && sc.rType == internal.RuneTypeEOF && sc.rRuneOK
-	sc.stuck = false
-	sc.repeat = false
-	if unread {
+	if sc.repeat || (sc.rType == internal.RuneTypeEOF && sc.rSize > 0) {
+		sc.repeat = false
 		// re-figure the rType and rErr
 		var err error
 		sc.rType, err = sc.parser.HandleRune(sc.rRune)
@@ -75,15 +71,15 @@ func (sc *runeTypeScannerImpl) Reset() {
 
 func (sc *runeTypeScannerImpl) ReadRuneType() (rune, int, internal.RuneType, error) {
 	switch {
-	case sc.stuck:
+	case sc.initialized && (sc.rType == internal.RuneTypeError || sc.rType == internal.RuneTypeEOF):
 		// do nothing
 	case sc.repeat:
 		_, _, _ = sc.inner.ReadRune()
 	default:
+		sc.initialized = true
 		var err error
 		sc.rRune, sc.rSize, err = sc.inner.ReadRune()
 		sc.offset += int64(sc.rSize)
-		sc.rRuneOK = err == nil
 		switch err {
 		case nil:
 			sc.rType, err = sc.parser.HandleRune(sc.rRune)
@@ -113,9 +109,7 @@ func (sc *runeTypeScannerImpl) ReadRuneType() (rune, int, internal.RuneType, err
 			}
 		}
 	}
-	sc.initialized = true
 	sc.repeat = false
-	sc.stuck = sc.rType == internal.RuneTypeEOF || sc.rType == internal.RuneTypeError
 	return sc.rRune, sc.rSize, sc.rType, sc.rErr
 }
 
@@ -137,7 +131,7 @@ func (sc *runeTypeScannerImpl) ReadRune() (rune, int, error) {
 // unread, or if that call returned a rune with size 0, then
 // ErrInvalidUnreadRune is returned.  Otherwise, nil is returned.
 func (sc *runeTypeScannerImpl) UnreadRune() error {
-	if !sc.initialized || sc.repeat || sc.rSize == 0 {
+	if sc.repeat || sc.rSize == 0 {
 		return ErrInvalidUnreadRune
 	}
 	sc.repeat = true
-- 
cgit v1.2.3-54-g00ecf