diff --git a/src/test/java/org/apache/commons/csv/CSVLexer1.java b/src/test/java/org/apache/commons/csv/CSVLexer1.java
new file mode 100644
index 00000000..1772b26a
--- /dev/null
+++ b/src/test/java/org/apache/commons/csv/CSVLexer1.java
@@ -0,0 +1,238 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.commons.csv;
+
+import java.io.IOException;
+
+import static org.apache.commons.csv.Token.Type.*;
+
+class CSVLexer1 extends Lexer {
+
+ private final StringBuilder wsBuf = new StringBuilder();
+
+ // ctor needs to be public so can be called dynamically by PerformanceTest class
+ public CSVLexer1(CSVFormat format, ExtendedBufferedReader in) {
+ super(format, in);
+ }
+
+ /**
+ * Returns the next token.
+ *
+ * A token corresponds to a term, a record change or an end-of-file indicator.
+ *
+ * @param tkn an existing Token object to reuse. The caller is responsible to initialize the Token.
+ * @return the next token found
+ * @throws java.io.IOException on stream access error
+ */
+ @Override
+ Token nextToken(Token tkn) throws IOException {
+ wsBuf.setLength(0); // reuse
+
+ // get the last read char (required for empty line detection)
+ int lastChar = in.readAgain();
+
+ // read the next char and set eol
+ /* note: unfortunately isEndOfLine may consumes a character silently.
+ * this has no effect outside of the method. so a simple workaround
+ * is to call 'readAgain' on the stream...
+ */
+ int c = in.read();
+ boolean eol = isEndOfLine(c);
+ c = in.readAgain();
+
+ // empty line detection: eol AND (last char was EOL or beginning)
+ if (format.isEmptyLinesIgnored()) {
+ while (eol
+ && (lastChar == '\n' || lastChar == '\r' || lastChar == ExtendedBufferedReader.UNDEFINED)
+ && !isEndOfFile(lastChar)) {
+ // go on char ahead ...
+ lastChar = c;
+ c = in.read();
+ eol = isEndOfLine(c);
+ c = in.readAgain();
+ // reached end of file without any content (empty line at the end)
+ if (isEndOfFile(c)) {
+ tkn.type = EOF;
+ return tkn;
+ }
+ }
+ }
+
+ // did we reach eof during the last iteration already ? EOF
+ if (isEndOfFile(lastChar) || (lastChar != format.getDelimiter() && isEndOfFile(c))) {
+ tkn.type = EOF;
+ return tkn;
+ }
+
+ // important: make sure a new char gets consumed in each iteration
+ while (!tkn.isReady && tkn.type != EOF) {
+ // ignore whitespaces at beginning of a token
+ if (format.isLeadingSpacesIgnored()) {
+ while (isWhitespace(c) && !eol) {
+ wsBuf.append((char) c);
+ c = in.read();
+ eol = isEndOfLine(c);
+ }
+ }
+
+ // ok, start of token reached: comment, encapsulated, or token
+ if (c == format.getCommentStart()) {
+ // ignore everything till end of line and continue (incr linecount)
+ in.readLine();
+ tkn = nextToken(tkn.reset());
+ } else if (c == format.getDelimiter()) {
+ // empty token return TOKEN("")
+ tkn.type = TOKEN;
+ tkn.isReady = true;
+ } else if (eol) {
+ // empty token return EORECORD("")
+ //noop: tkn.content.append("");
+ tkn.type = EORECORD;
+ tkn.isReady = true;
+ } else if (c == format.getEncapsulator()) {
+ // consume encapsulated token
+ encapsulatedTokenLexer(tkn, c);
+ } else if (isEndOfFile(c)) {
+ // end of file return EOF()
+ //noop: tkn.content.append("");
+ tkn.type = EOF;
+ tkn.isReady = true;
+ } else {
+ // next token must be a simple token
+ // add removed blanks when not ignoring whitespace chars...
+ if (!format.isLeadingSpacesIgnored()) {
+ tkn.content.append(wsBuf);
+ }
+ simpleTokenLexer(tkn, c);
+ }
+ }
+ return tkn;
+ }
+
+ /**
+ * A simple token lexer
+ *
+ * Simple token are tokens which are not surrounded by encapsulators.
+ * A simple token might contain escaped delimiters (as \, or \;). The
+ * token is finished when one of the following conditions become true:
+ *
+ * - end of line has been reached (EORECORD)
+ * - end of stream has been reached (EOF)
+ * - an unescaped delimiter has been reached (TOKEN)
+ *
+ *
+ * @param tkn the current token
+ * @param c the current character
+ * @return the filled token
+ * @throws IOException on stream access error
+ */
+ private Token simpleTokenLexer(Token tkn, int c) throws IOException {
+ while (true) {
+ if (isEndOfLine(c)) {
+ // end of record
+ tkn.type = EORECORD;
+ tkn.isReady = true;
+ break;
+ } else if (isEndOfFile(c)) {
+ // end of file
+ tkn.type = EOF;
+ tkn.isReady = true;
+ break;
+ } else if (c == format.getDelimiter()) {
+ // end of token
+ tkn.type = TOKEN;
+ tkn.isReady = true;
+ break;
+ } else if (c == format.getEscape()) {
+ tkn.content.append((char) readEscape(c));
+ } else {
+ tkn.content.append((char) c);
+ }
+
+ c = in.read();
+ }
+
+ if (format.isTrailingSpacesIgnored()) {
+ trimTrailingSpaces(tkn.content);
+ }
+
+ return tkn;
+ }
+
+ /**
+ * An encapsulated token lexer
+ *
+ * Encapsulated tokens are surrounded by the given encapsulating-string.
+ * The encapsulator itself might be included in the token using a
+ * doubling syntax (as "", '') or using escaping (as in \", \').
+ * Whitespaces before and after an encapsulated token are ignored.
+ *
+ * @param tkn the current token
+ * @param c the current character
+ * @return a valid token object
+ * @throws IOException on invalid state
+ */
+ private Token encapsulatedTokenLexer(Token tkn, int c) throws IOException {
+ // save current line
+ int startLineNumber = getLineNumber();
+ // ignore the given delimiter
+ // assert c == delimiter;
+ while (true) {
+ c = in.read();
+
+ if (c == format.getEscape()) {
+ tkn.content.append((char) readEscape(c));
+ } else if (c == format.getEncapsulator()) {
+ if (in.lookAhead() == format.getEncapsulator()) {
+ // double or escaped encapsulator -> add single encapsulator to token
+ c = in.read();
+ tkn.content.append((char) c);
+ } else {
+ // token finish mark (encapsulator) reached: ignore whitespace till delimiter
+ while (true) {
+ c = in.read();
+ if (c == format.getDelimiter()) {
+ tkn.type = TOKEN;
+ tkn.isReady = true;
+ return tkn;
+ } else if (isEndOfFile(c)) {
+ tkn.type = EOF;
+ tkn.isReady = true;
+ return tkn;
+ } else if (isEndOfLine(c)) {
+ // ok eo token reached
+ tkn.type = EORECORD;
+ tkn.isReady = true;
+ return tkn;
+ } else if (!isWhitespace(c)) {
+ // error invalid char between token and next delimiter
+ throw new IOException("(line " + getLineNumber() + ") invalid char between encapsulated token and delimiter");
+ }
+ }
+ }
+ } else if (isEndOfFile(c)) {
+ // error condition (end of file before end of token)
+ throw new IOException("(startline " + startLineNumber + ") EOF reached before encapsulated token finished");
+ } else {
+ // consume character
+ tkn.content.append((char) c);
+ }
+ }
+ }
+
+}
\ No newline at end of file