From 788628d9025319461b08fc4de985fd09b2a98b58 Mon Sep 17 00:00:00 2001
From: z7zmey <z7zmey@gmail.com>
Date: Mon, 4 Jun 2018 21:21:04 +0300
Subject: [PATCH] #21 scanner.Lexer.charsToBytes optimization

---
 scanner/lexer.go | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/scanner/lexer.go b/scanner/lexer.go
index a2f322f..59afec5 100644
--- a/scanner/lexer.go
+++ b/scanner/lexer.go
@@ -441,6 +441,7 @@ type Lexer struct {
 	PhpDocComment string
 	Comments      []comment.Comment
 	heredocLabel  []lex.Char
+	tokenBytesBuf *bytes.Buffer
 }
 
 // Rune2Class returns the rune integer id
@@ -468,7 +469,7 @@ func NewLexer(src io.Reader, fName string) *Lexer {
 	if err != nil {
 		panic(err)
 	}
-	return &Lexer{lx, []int{0}, "", nil, nil}
+	return &Lexer{lx, []int{0}, "", nil, nil, &bytes.Buffer{}}
 }
 
 func (l *Lexer) ungetChars(n int) []lex.Char {
@@ -527,11 +528,13 @@ func (l *Lexer) addComment(c comment.Comment) {
 }
 
 func (l *Lexer) charsToBytes(chars []lex.Char) []byte {
-	bytesBuf := bytes.Buffer{}
-
 	for _, c := range chars {
-		bytesBuf.WriteRune(c.Rune)
+		l.tokenBytesBuf.WriteRune(c.Rune)
 	}
 
-	return bytesBuf.Bytes()
+	r := l.tokenBytesBuf.Bytes()
+
+	l.tokenBytesBuf.Reset()
+
+	return r
 }