From 7998d05113755cb851e5267055ee13857a4c6dad Mon Sep 17 00:00:00 2001
From: Maurice Makaay <maurice@makaay.nl>
Date: Sat, 20 Jul 2019 01:50:12 +0000
Subject: [PATCH] More efficient version of MatchOctet.

---
 tokenize/handlers_builtin.go | 54 ++++++++++++++++++++++++++++--------
 1 file changed, 42 insertions(+), 12 deletions(-)

diff --git a/tokenize/handlers_builtin.go b/tokenize/handlers_builtin.go
index 36cf01d..a8c3ebf 100644
--- a/tokenize/handlers_builtin.go
+++ b/tokenize/handlers_builtin.go
@@ -736,15 +736,16 @@ func MatchSeq(handlers ...Handler) Handler {
 // that applies is used for reporting back a match.
 func MatchAny(handlers ...Handler) Handler {
 	return func(t *API) bool {
+		child := t.Fork()
 		for _, handler := range handlers {
-			child := t.Fork()
 			if handler(t) {
 				t.Merge(child)
 				t.Dispose(child)
 				return true
 			}
-			t.Dispose(child)
+			t.Input.Reset()
 		}
+		t.Dispose(child)
 
 		return false
 	}
@@ -1341,21 +1342,50 @@ func MatchHexDigit() Handler {
 // When the normalize parameter is set to true, then leading zeroes will be
 // stripped from the octet.
 func MatchOctet(normalize bool) Handler {
-	max3Digits := MatchMinMax(1, 3, MatchDigit())
 	return func(t *API) bool {
-		if !max3Digits(t) {
+		// Digit 1
+		b0, err := t.Input.PeekByte(0)
+		if err != nil || b0 < '0' || b0 > '9' {
 			return false
 		}
-		value, _ := strconv.ParseInt(t.Output.String(), 10, 16)
-		if value > 255 {
-			return false
+
+		// Digit 2
+		b1, err := t.Input.PeekByte(1)
+		if err != nil || b1 < '0' || b1 > '9' {
+			// Output 1-digit octet.
+			t.Input.AcceptByte(b0)
+			return true
 		}
-		if normalize {
-			runes := t.Output.Runes()
-			for len(runes) > 1 && runes[0] == '0' {
-				runes = runes[1:]
+
+		// Digit 3
+		b2, err := t.Input.PeekByte(2)
+		if err != nil || b2 < '0' || b2 > '9' {
+			// Output 2-digit octet.
+			if normalize && b0 == '0' {
+				t.Input.SkipByte(b0)
+				t.Input.AcceptByte(b1)
+			} else {
+				t.Input.AcceptBytes(b0, b1)
 			}
-			t.Output.SetRunes(runes...)
+			return true
+		}
+
+		// The value of the octet must be between 0 - 255.
+		if b0 > '2' || (b0 == '2' && b1 > '5') || (b0 == '2' && b1 == '5' && b2 > '5') {
+			return false
+		}
+
+		// Output 3-digit octet.
+		if normalize && b0 == '0' {
+			t.Input.SkipByte(b0)
+			if b1 == '0' {
+				t.Input.SkipByte(b1)
+			} else {
+				t.Input.AcceptByte(b1)
+			}
+			t.Input.AcceptByte(b2)
+		} else {
+			t.Input.AcceptBytes(b0, b1, b2)
 		}
 		return true
 	}