Make parsing 50% faster by elminating allocation
* We now use a [1024]byte buffer to store the token * Return an error when this is to small
This commit is contained in:
Miek Gieben
parent
431b800ae0
commit
06ab0a998a
79
zscan.go
79
zscan.go
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@ -11,6 +11,7 @@ import (
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// Only used when debugging the parser itself.
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var _DEBUG = false
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const maxTok = 1024
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// Tokinize a RFC 1035 zone file. The tokenizer will normalize it:
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// * Add ownernames if they are left blank;
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@ -88,9 +89,9 @@ type Token struct {
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// The class defaults to IN and TTL defaults to DefaultTtl
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func NewRR(s string) (RR, error) {
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if s[len(s)-1] != '\n' { // We need a closing newline
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return ReadRR(strings.NewReader(s+"\n"), "")
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return ReadRR(strings.NewReader(s+"\n"), "")
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}
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return ReadRR(strings.NewReader(s), "")
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return ReadRR(strings.NewReader(s), "")
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}
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// Ioreader here, or filename which *we* open....???
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@ -98,11 +99,11 @@ func NewRR(s string) (RR, error) {
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// ReadRR reads the RR contained in q. Only the first RR is returned.
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// The class defaults to IN and TTL defaults to DefaultTtl
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func ReadRR(q io.Reader, filename string) (RR, error) {
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r := <-ParseZone(q, filename)
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if r.Error != nil {
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return nil, r.Error
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}
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return r.RR, nil
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r := <-ParseZone(q, filename)
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if r.Error != nil {
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return nil, r.Error
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}
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return r.RR, nil
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}
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// ParseZone reads a RFC 1035 zone from r. It returns each parsed RR or on error
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@ -194,10 +195,10 @@ func parseZone(r io.Reader, f string, t chan Token, include int) {
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t <- Token{Error: &ParseError{f, "Failed to open `" + l.token + "'", l}}
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return
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}
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if include + 1 > 7 {
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t <- Token{Error: &ParseError{f, "Too deeply nested $INCLUDE", l}}
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return
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}
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if include+1 > 7 {
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t <- Token{Error: &ParseError{f, "Too deeply nested $INCLUDE", l}}
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return
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}
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parseZone(r1, l.token, t, include+1)
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st = _EXPECT_OWNER_DIR
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case _EXPECT_DIRTTL_BL:
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@ -357,7 +358,8 @@ func (l lex) String() string {
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// zlexer scans the sourcefile and returns tokens on the channel c.
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func zlexer(s scanner.Scanner, c chan lex) {
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var l lex
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str := "" // Hold the current read text
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str := make([]byte, maxTok) // Should be enough for any token
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stri := 0 // Offset in str (0 means empty)
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quote := false
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escape := false
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space := false
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@ -370,21 +372,26 @@ func zlexer(s scanner.Scanner, c chan lex) {
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for tok != scanner.EOF {
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l.column = s.Position.Column
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l.line = s.Position.Line
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if stri > maxTok {
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l.err = "tok length insufficient for parsing"
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c <- l
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return
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}
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switch x := s.TokenText(); x {
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case " ", "\t":
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escape = false
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if commt {
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break
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}
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if str == "" {
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if stri == 0 {
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//l.value = _BLANK
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//l.token = " "
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} else if owner {
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// If we have a string and its the first, make it an owner
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l.value = _OWNER
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l.token = str
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l.token = string(str[:stri])
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// escape $... start with a \ not a $, so this will work
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switch str {
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switch string(str[:stri]) {
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case "$TTL":
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l.value = _DIRTTL
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case "$ORIGIN":
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@ -395,7 +402,7 @@ func zlexer(s scanner.Scanner, c chan lex) {
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c <- l
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} else {
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l.value = _STRING
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l.token = str
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l.token = string(str[:stri])
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if !rrtype {
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if _, ok := Str_rr[strings.ToUpper(l.token)]; ok {
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@ -408,7 +415,7 @@ func zlexer(s scanner.Scanner, c chan lex) {
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}
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c <- l
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}
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str = ""
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stri = 0
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if !space && !commt {
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l.value = _BLANK
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l.token = " "
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@ -419,12 +426,14 @@ func zlexer(s scanner.Scanner, c chan lex) {
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case ";":
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if escape {
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escape = false
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str += ";"
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str[stri] = ';'
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stri++
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break
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}
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if quote {
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// Inside quoted text we allow ;
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str += ";"
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str[stri] = ';'
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stri++
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break
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}
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commt = true
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@ -435,7 +444,7 @@ func zlexer(s scanner.Scanner, c chan lex) {
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// Reset a comment
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commt = false
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rrtype = false
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str = ""
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stri = 0
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// If not in a brace this ends the comment AND the RR
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if brace == 0 {
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owner = true
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@ -445,9 +454,9 @@ func zlexer(s scanner.Scanner, c chan lex) {
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}
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break
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}
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if str != "" {
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if stri != 0 {
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l.value = _STRING
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l.token = str
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l.token = string(str[:stri])
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if !rrtype {
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if _, ok := Str_rr[strings.ToUpper(l.token)]; ok {
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l.value = _RRTYPE
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@ -471,7 +480,7 @@ func zlexer(s scanner.Scanner, c chan lex) {
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space = true
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}
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str = ""
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stri = 0
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commt = false
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rrtype = false
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owner = true
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@ -480,18 +489,21 @@ func zlexer(s scanner.Scanner, c chan lex) {
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break
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}
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if escape {
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str += "\\"
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str[stri] = '\\'
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stri++
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escape = false
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break
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}
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str += "\\"
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str[stri] = '\\'
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stri++
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escape = true
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case "\"":
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if commt {
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break
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}
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if escape {
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str += "\""
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str[stri] = '"'
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stri++
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escape = false
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break
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}
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@ -502,7 +514,8 @@ func zlexer(s scanner.Scanner, c chan lex) {
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break
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}
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if escape {
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str += "("
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str[stri] = '('
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stri++
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escape = false
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break
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}
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@ -512,13 +525,14 @@ func zlexer(s scanner.Scanner, c chan lex) {
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break
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}
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if escape {
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str += ")"
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str[stri] = ')'
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stri++
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escape = false
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break
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}
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brace--
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if brace < 0 {
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l.err = "Extra closing brace"
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l.err = "extra closing brace"
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c <- l
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return
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}
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@ -527,15 +541,16 @@ func zlexer(s scanner.Scanner, c chan lex) {
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break
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}
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escape = false
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str += x
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str[stri] = byte(x[0]) // This should be ok...
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stri++
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space = false
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}
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tok = s.Scan()
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}
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// Hmm.
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if len(str) > 0 {
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if stri > 0 {
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// Send remainder
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l.token = str
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l.token = string(str[:stri])
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l.value = _STRING
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c <- l
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}
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