diff --git a/btparser/btparser.vcxproj b/btparser/btparser.vcxproj
index f8d4fef..e72d0c2 100644
--- a/btparser/btparser.vcxproj
+++ b/btparser/btparser.vcxproj
@@ -20,6 +20,7 @@
   </ItemGroup>
   <ItemGroup>
     <ClCompile Include="filehelper.cpp" />
+    <ClCompile Include="lexer.cpp" />
     <ClCompile Include="main.cpp" />
     <ClCompile Include="stringutils.cpp" />
   </ItemGroup>
@@ -28,6 +29,7 @@
     <ClInclude Include="filehelper.h" />
     <ClInclude Include="handle.h" />
     <ClInclude Include="keywords.h" />
+    <ClInclude Include="lexer.h" />
     <ClInclude Include="operators.h" />
     <ClInclude Include="stringutils.h" />
     <ClInclude Include="testfiles.h" />
diff --git a/btparser/btparser.vcxproj.filters b/btparser/btparser.vcxproj.filters
index b220af6..19271c0 100644
--- a/btparser/btparser.vcxproj.filters
+++ b/btparser/btparser.vcxproj.filters
@@ -24,6 +24,9 @@
     <ClCompile Include="stringutils.cpp">
       <Filter>Source Files</Filter>
     </ClCompile>
+    <ClCompile Include="lexer.cpp">
+      <Filter>Source Files</Filter>
+    </ClCompile>
   </ItemGroup>
   <ItemGroup>
     <ClInclude Include="filehelper.h">
@@ -47,5 +50,8 @@
     <ClInclude Include="operators.h">
       <Filter>Header Files</Filter>
     </ClInclude>
+    <ClInclude Include="lexer.h">
+      <Filter>Header Files</Filter>
+    </ClInclude>
   </ItemGroup>
 </Project>
\ No newline at end of file
diff --git a/btparser/lexer.cpp b/btparser/lexer.cpp
new file mode 100644
index 0000000..a0ba1ce
--- /dev/null
+++ b/btparser/lexer.cpp
@@ -0,0 +1,499 @@
+#include "lexer.h"
+#include "stringutils.h"
+#include <cctype>
+#include "filehelper.h"
+
+#define MAKE_OP_TRIPLE(ch1, ch2, ch3) (ch3 << 16 | ch2 << 8 | ch1)
+#define MAKE_OP_DOUBLE(ch1, ch2) (ch2 << 8 | ch1)
+#define MAKE_OP_SINGLE(ch1) (ch1)
+#define DEFAULT_STRING_BUFFER 65536
+
+static void clearReserve(std::string & str, size_t reserve = DEFAULT_STRING_BUFFER)
+{
+    str.clear();
+    str.reserve(reserve);
+}
+
+static void appendCh(std::string & str, char ch)
+{
+    str.resize(str.size() + 1);
+    str[str.size() - 1] = ch;
+}
+
+static const char* convertNumber(const char* str, uint64_t & result, int radix)
+{
+    errno = 0;
+    char* end;
+    result = strtoull(str, &end, radix);
+    if (!result && end == str)
+        return "not a number";
+    if (result == ULLONG_MAX && errno)
+        return "does not fit";
+    if (*end)
+        return "str not completely consumed";
+    return nullptr;
+}
+
+Lexer::Lexer()
+{
+    setupTokenMaps();
+}
+
+bool Lexer::ReadInputFile(const std::string & filename)
+{
+    resetLexerState();
+    return FileHelper::ReadAllData(filename, mInput);
+}
+
+bool Lexer::DoLexing(std::vector<TokenState> & tokens, std::string & error)
+{
+    while (true)
+    {
+        auto token = getToken();
+        mState.Token = token;
+        if (token == tok_eof)
+            break;
+        if (token == tok_error)
+        {
+            error = StringUtils::sprintf("line %d, col %d: %s", mState.CurLine + 1, mState.LineIndex, mError.c_str());
+            return false;
+        }
+        tokens.push_back(mState);
+    }
+    return true;
+}
+
+bool Lexer::Test(const std::function<void(const std::string & line)> & lexEnum, bool output)
+{
+    size_t line = 0;
+    if (output)
+        lexEnum("1: ");
+    Token tok;
+    std::string toks;
+    clearReserve(toks);
+    char newlineText[128] = "";
+    do
+    {
+        tok = getToken();
+        if (!output)
+            continue;
+        toks.clear();
+        while (line < mState.CurLine)
+        {
+            line++;
+            sprintf_s(newlineText, "\n%d: ", line + 1);
+            toks.append(newlineText);
+        }
+        toks.append(tokString(tok));
+        appendCh(toks, ' ');
+        lexEnum(toks);
+    } while (tok != tok_eof && tok != tok_error);
+    if (tok != tok_error && tok != tok_eof)
+        tok = reportError("lexer did not finish at the end of the file");
+    for (const auto& warning : mWarnings)
+        if (output)
+            lexEnum("\nwarning: " + warning);
+    return tok != tok_error;
+}
+
+Lexer::Token Lexer::getToken()
+{
+    //skip whitespace
+    while (isspace(mLastChar))
+    {
+        if (mLastChar == '\n')
+            signalNewLine();
+        nextChar();
+    }
+
+    //skip \\[\r\n]
+    if (mLastChar == '\\' && (peekChar() == '\r' || peekChar() == '\n'))
+    {
+        nextChar();
+        return getToken();
+    }
+
+    //character literal
+    if (mLastChar == '\'')
+    {
+        std::string charLit;
+        while (true)
+        {
+            nextChar();
+            if (mLastChar == EOF) //end of file
+                return reportError("unexpected end of file in character literal (1)");
+            if (mLastChar == '\r' || mLastChar == '\n')
+                return reportError("unexpected newline in character literal (1)");
+            if (mLastChar == '\'') //end of character literal
+            {
+                if (charLit.length() != 1)
+                    return reportError(StringUtils::sprintf("invalid character literal '%s'", charLit.c_str()));
+                mState.CharLit = charLit[0];
+                nextChar();
+                return tok_charlit;
+            }
+            if (mLastChar == '\\') //escape sequence
+            {
+                nextChar();
+                if (mLastChar == EOF)
+                    return reportError("unexpected end of file in character literal (2)");
+                if (mLastChar == '\r' || mLastChar == '\n')
+                    return reportError("unexpected newline in character literal (2)");
+                if (mLastChar == '\'' || mLastChar == '\"' || mLastChar == '?' || mLastChar == '\\')
+                    mLastChar = mLastChar;
+                else if (mLastChar == 'a')
+                    mLastChar = '\a';
+                else if (mLastChar == 'b')
+                    mLastChar = '\b';
+                else if (mLastChar == 'f')
+                    mLastChar = '\f';
+                else if (mLastChar == 'n')
+                    mLastChar = '\n';
+                else if (mLastChar == 'r')
+                    mLastChar = '\r';
+                else if (mLastChar == 't')
+                    mLastChar = '\t';
+                else if (mLastChar == 'v')
+                    mLastChar = '\v';
+                else if (mLastChar == '0')
+                    mLastChar = '\0';
+                else if (mLastChar == 'x') //\xHH
+                {
+                    auto ch1 = nextChar();
+                    auto ch2 = nextChar();
+                    if (isxdigit(ch1) && isxdigit(ch2))
+                    {
+                        char byteStr[3] = "";
+                        byteStr[0] = ch1;
+                        byteStr[1] = ch2;
+                        uint64_t hexData;
+                        auto error = convertNumber(byteStr, hexData, 16);
+                        if (error)
+                            return reportError(StringUtils::sprintf("convertNumber failed (%s) for hex sequence \"\\x%c%c\" in character literal", error, ch1, ch2));
+                        mLastChar = hexData & 0xFF;
+                    }
+                    else
+                        return reportError(StringUtils::sprintf("invalid hex sequence \"\\x%c%c\" in character literal", ch1, ch2));
+                }
+                else
+                    return reportError(StringUtils::sprintf("invalid escape sequence \"\\%c\" in character literal", mLastChar));
+            }
+            charLit += mLastChar;
+        }
+    }
+
+    //string literal
+    if (mLastChar == '\"')
+    {
+        mState.StringLit.clear();
+        while (true)
+        {
+            nextChar();
+            if (mLastChar == EOF) //end of file
+                return reportError("unexpected end of file in string literal (1)");
+            if (mLastChar == '\r' || mLastChar == '\n')
+                return reportError("unexpected newline in string literal (1)");
+            if (mLastChar == '\"') //end of string literal
+            {
+                nextChar();
+                return tok_stringlit;
+            }
+            if (mLastChar == '\\') //escape sequence
+            {
+                nextChar();
+                if (mLastChar == EOF)
+                    return reportError("unexpected end of file in string literal (2)");
+                if (mLastChar == '\r' || mLastChar == '\n')
+                    return reportError("unexpected newline in string literal (2)");
+                if (mLastChar == '\'' || mLastChar == '\"' || mLastChar == '?' || mLastChar == '\\')
+                    mLastChar = mLastChar;
+                else if (mLastChar == 'a')
+                    mLastChar = '\a';
+                else if (mLastChar == 'b')
+                    mLastChar = '\b';
+                else if (mLastChar == 'f')
+                    mLastChar = '\f';
+                else if (mLastChar == 'n')
+                    mLastChar = '\n';
+                else if (mLastChar == 'r')
+                    mLastChar = '\r';
+                else if (mLastChar == 't')
+                    mLastChar = '\t';
+                else if (mLastChar == 'v')
+                    mLastChar = '\v';
+                else if (mLastChar == '0')
+                    mLastChar = '\0';
+                else if (mLastChar == 'x') //\xHH
+                {
+                    auto ch1 = nextChar();
+                    auto ch2 = nextChar();
+                    if (isxdigit(ch1) && isxdigit(ch2))
+                    {
+                        char byteStr[3] = "";
+                        byteStr[0] = ch1;
+                        byteStr[1] = ch2;
+                        uint64_t hexData;
+                        auto error = convertNumber(byteStr, hexData, 16);
+                        if (error)
+                            return reportError(StringUtils::sprintf("convertNumber failed (%s) for hex sequence \"\\x%c%c\" in string literal", error, ch1, ch2));
+                        mLastChar = hexData & 0xFF;
+                    }
+                    else
+                        return reportError(StringUtils::sprintf("invalid hex sequence \"\\x%c%c\" in string literal", ch1, ch2));
+                }
+                else
+                    return reportError(StringUtils::sprintf("invalid escape sequence \"\\%c\" in string literal", mLastChar));
+            }
+            appendCh(mState.StringLit, mLastChar);
+        }
+    }
+
+    //identifier/keyword
+    if (isalpha(mLastChar) || mLastChar == '_') //[a-zA-Z_]
+    {
+        mState.IdentifierStr = mLastChar;
+        nextChar();
+        while (isalnum(mLastChar) || mLastChar == '_') //[0-9a-zA-Z_]
+        {
+            appendCh(mState.IdentifierStr, mLastChar);
+            nextChar();
+        }
+
+        //keywords
+        auto found = mKeywordMap.find(mState.IdentifierStr);
+        if (found != mKeywordMap.end())
+            return found->second;
+
+        return tok_identifier;
+    }
+
+    //hex numbers
+    if (mLastChar == '0' && peekChar() == 'x') //0x
+    {
+        nextChar(); //consume the 'x'
+        mNumStr.clear();
+
+        while (isxdigit(nextChar())) //[0-9a-fA-F]*
+            appendCh(mNumStr, mLastChar);
+
+        if (!mNumStr.length()) //check for error condition
+            return reportError("no hex digits after \"0x\" prefix");
+
+        auto error = convertNumber(mNumStr.c_str(), mState.NumberVal, 16);
+        if (error)
+            return reportError(StringUtils::sprintf("convertNumber failed (%s) on hexadecimal number", error));
+        mIsHexNumberVal = true;
+        return tok_number;
+    }
+    if (isdigit(mLastChar)) //[0-9]
+    {
+        mNumStr = mLastChar;
+
+        while (isdigit(nextChar())) //[0-9]*
+            mNumStr += mLastChar;
+
+        auto error = convertNumber(mNumStr.c_str(), mState.NumberVal, 10);
+        if (error)
+            return reportError(StringUtils::sprintf("convertNumber failed (%s) on decimal number", error));
+        mIsHexNumberVal = false;
+        return tok_number;
+    }
+
+    //comments
+    if (mLastChar == '/' && peekChar() == '/') //line comment
+    {
+        do
+        {
+            if (mLastChar == '\n')
+                signalNewLine();
+            nextChar();
+        } while (!(mLastChar == EOF || mLastChar == '\n'));
+
+        return getToken(); //interpret the next line
+    }
+    if (mLastChar == '/' && peekChar() == '*') //block comment
+    {
+        do
+        {
+            if (mLastChar == '\n')
+                signalNewLine();
+            nextChar();
+        } while (!(mLastChar == EOF || mLastChar == '*' && peekChar() == '/'));
+
+        if (mLastChar == EOF) //unexpected end of file
+        {
+            mState.LineIndex++;
+            return reportError("unexpected end of file in block comment");
+        }
+
+        nextChar();
+        nextChar();
+        return getToken(); //get the next non-comment token
+    }
+
+    //operators
+    auto opFound = mOpTripleMap.find(MAKE_OP_TRIPLE(mLastChar, peekChar(), peekChar(1)));
+    if (opFound != mOpTripleMap.end())
+    {
+        nextChar();
+        nextChar();
+        nextChar();
+        return opFound->second;
+    }
+    opFound = mOpDoubleMap.find(MAKE_OP_DOUBLE(mLastChar, peekChar()));
+    if (opFound != mOpDoubleMap.end())
+    {
+        nextChar();
+        nextChar();
+        return opFound->second;
+    }
+    opFound = mOpSingleMap.find(MAKE_OP_SINGLE(mLastChar));
+    if (opFound != mOpSingleMap.end())
+    {
+        nextChar();
+        return opFound->second;
+    }
+
+    //end of file
+    if (mLastChar == EOF)
+        return tok_eof;
+
+    //unknown character
+    return reportError(StringUtils::sprintf("unexpected character \'%c\'", mLastChar));
+}
+
+Lexer::Token Lexer::reportError(const std::string & error)
+{
+    mError = error;
+    return tok_error;
+}
+
+int Lexer::nextChar()
+{
+    return mLastChar = readChar();
+}
+
+void Lexer::reportWarning(const std::string & warning)
+{
+    mWarnings.push_back(warning);
+}
+
+void Lexer::resetLexerState()
+{
+    mInput.clear();
+    mInput.reserve(1024 * 1024);
+    mIndex = 0;
+    mError.clear();
+    mWarnings.clear();
+    clearReserve(mState.IdentifierStr);
+    mState.NumberVal = 0;
+    mIsHexNumberVal = false;
+    clearReserve(mState.StringLit);
+    clearReserve(mNumStr, 16);
+    mState.CharLit = '\0';
+    mLastChar = ' ';
+    mState.CurLine = 0;
+    mState.LineIndex = 0;
+}
+
+void Lexer::setupTokenMaps()
+{
+    //setup keyword map
+#define DEF_KEYWORD(keyword) mKeywordMap[#keyword] = tok_##keyword;
+#include "keywords.h"
+#undef DEF_KEYWORD
+
+    //setup token maps
+#define DEF_OP_TRIPLE(enumval, ch1, ch2, ch3) mOpTripleMap[MAKE_OP_TRIPLE(ch1, ch2, ch3)] = tok_##enumval;
+#define DEF_OP_DOUBLE(enumval, ch1, ch2) mOpDoubleMap[MAKE_OP_DOUBLE(ch1, ch2)] = tok_##enumval;
+#define DEF_OP_SINGLE(enumval, ch1) mOpSingleMap[MAKE_OP_SINGLE(ch1)] = tok_##enumval;
+#include "operators.h"
+#undef DEF_OP_TRIPLE
+#undef DEF_OP_DOUBLE
+#undef DEF_OP_SINGLE
+
+    //setup reverse token maps
+#define DEF_KEYWORD(keyword) mReverseTokenMap[tok_##keyword] = #keyword;
+#include "keywords.h"
+#undef DEF_KEYWORD
+
+#define DEF_OP_TRIPLE(enumval, ch1, ch2, ch3) mReverseTokenMap[tok_##enumval] = std::string({ch1, ch2, ch3});
+#define DEF_OP_DOUBLE(enumval, ch1, ch2) mReverseTokenMap[tok_##enumval] = std::string({ch1, ch2});
+#define DEF_OP_SINGLE(enumval, ch1) mReverseTokenMap[tok_##enumval] = std::string({ch1});
+#include "operators.h"
+#undef DEF_OP_TRIPLE
+#undef DEF_OP_DOUBLE
+#undef DEF_OP_SINGLE
+}
+
+std::string Lexer::tokString(Token tok)
+{
+    switch (tok)
+    {
+    case tok_eof: return "tok_eof";
+    case tok_error: return StringUtils::sprintf("error(line %d, col %d, \"%s\")", mState.CurLine + 1, mState.LineIndex, mError.c_str());
+    case tok_identifier: return mState.IdentifierStr;
+    case tok_number: return StringUtils::sprintf(mIsHexNumberVal ? "0x%llX" : "%llu", mState.NumberVal);
+    case tok_stringlit: return StringUtils::sprintf("\"%s\"", StringUtils::Escape(mState.StringLit).c_str());
+    case tok_charlit:
+        {
+            std::string s;
+            s = mState.CharLit;
+            return StringUtils::sprintf("'%s'", StringUtils::Escape(s).c_str());
+        }
+    default:
+        {
+            auto found = mReverseTokenMap.find(Token(tok));
+            if (found != mReverseTokenMap.end())
+                return found->second;
+            return "<UNKNOWN TOKEN>";
+        }
+    }
+}
+
+int Lexer::peekChar(size_t distance)
+{
+    if (mIndex + distance >= mInput.size())
+        return EOF;
+    auto ch = mInput[mIndex + distance];
+    if (ch == '\0')
+    {
+        reportWarning(StringUtils::sprintf("\\0 character in file data"));
+        return peekChar(distance + 1);
+    }
+    return ch;
+}
+
+int Lexer::readChar()
+{
+    if (mIndex == mInput.size())
+        return EOF;
+    auto ch = mInput[mIndex++];
+    mState.LineIndex++;
+    if (ch == '\0')
+    {
+        reportWarning(StringUtils::sprintf("\\0 character in file data"));
+        return readChar();
+    }
+    return ch;
+}
+
+bool Lexer::checkString(const std::string & expected)
+{
+    for (size_t i = 0; i < expected.size(); i++)
+    {
+        auto ch = peekChar(i);
+        if (ch == EOF)
+            return false;
+        if (ch != uint8_t(expected[i]))
+            return false;
+    }
+    mIndex += expected.size();
+    return true;
+}
+
+void Lexer::signalNewLine()
+{
+    mState.CurLine++;
+    mState.LineIndex = 0;
+}
diff --git a/btparser/lexer.h b/btparser/lexer.h
new file mode 100644
index 0000000..3e55583
--- /dev/null
+++ b/btparser/lexer.h
@@ -0,0 +1,81 @@
+#pragma once
+
+#include <cstdint>
+#include <vector>
+#include <unordered_map>
+#include <functional>
+
+class Lexer
+{
+public:
+    enum Token
+    {
+        //status tokens
+        tok_eof = -10000,
+        tok_error,
+
+        //keywords
+#define DEF_KEYWORD(keyword) tok_##keyword,
+#include "keywords.h"
+#undef DEF_KEYWORD
+
+        //others
+        tok_identifier, //[a-zA-Z_][a-zA-Z0-9_]
+        tok_number, //(0x[0-9a-fA-F]+)|([0-9]+)
+        tok_stringlit, //"([^\\"]|\\([\\"'?abfnrtv0]|x[0-9a-fA-f]{2}))*"
+        tok_charlit, //'([^\\]|\\([\\"'?abfnrtv0]|x[0-9a-fA-f]{2}))'
+
+        //operators
+#define DEF_OP_TRIPLE(enumval, ch1, ch2, ch3) tok_##enumval,
+#define DEF_OP_DOUBLE(enumval, ch1, ch2) tok_##enumval,
+#define DEF_OP_SINGLE(enumval, ch1) tok_##enumval,
+#include "operators.h"
+#undef DEF_OP_TRIPLE
+#undef DEF_OP_DOUBLE
+#undef DEF_OP_SINGLE
+    };
+
+    struct TokenState
+    {
+        Token Token;
+        std::string IdentifierStr; //tok_identifier
+        uint64_t NumberVal = 0; //tok_number
+        std::string StringLit; //tok_stringlit
+        char CharLit = '\0'; //tok_charlit
+
+        size_t CurLine = 0;
+        size_t LineIndex = 0;
+    };
+
+    explicit Lexer();
+    bool ReadInputFile(const std::string & filename);
+    bool DoLexing(std::vector<TokenState> & tokens, std::string & error);
+    bool Test(const std::function<void(const std::string & line)> & lexEnum, bool output = true);
+
+private:
+    TokenState mState;
+    std::vector<std::string> mWarnings;
+    std::string mError;
+    std::vector<uint8_t> mInput;
+    size_t mIndex = 0;
+    bool mIsHexNumberVal = false;
+    std::string mNumStr;
+    int mLastChar = ' ';
+    std::unordered_map<std::string, Token> mKeywordMap;
+    std::unordered_map<Token, std::string> mReverseTokenMap;
+    std::unordered_map<int, Token> mOpTripleMap;
+    std::unordered_map<int, Token> mOpDoubleMap;
+    std::unordered_map<int, Token> mOpSingleMap;
+
+    void resetLexerState();
+    void setupTokenMaps();
+    Token reportError(const std::string & error);
+    void reportWarning(const std::string & warning);
+    std::string tokString(Token tok);
+    int peekChar(size_t distance = 0);
+    int readChar();
+    bool checkString(const std::string & expected);
+    int nextChar();
+    void signalNewLine();
+    Token getToken();
+};
\ No newline at end of file
diff --git a/btparser/main.cpp b/btparser/main.cpp
index c4f71e7..365e73c 100644
--- a/btparser/main.cpp
+++ b/btparser/main.cpp
@@ -1,567 +1,27 @@
 #include <windows.h>
 #include <stdio.h>
-#include <string>
-#include <stdint.h>
-#include <unordered_map>
-#include <functional>
-#include <vector>
-#include "filehelper.h"
-#include "stringutils.h"
 #include "testfiles.h"
+#include "lexer.h"
+#include "filehelper.h"
 
-#define MAKE_OP_TRIPLE(ch1, ch2, ch3) (ch3 << 16 | ch2 << 8 | ch1)
-#define MAKE_OP_DOUBLE(ch1, ch2) (ch2 << 8 | ch1)
-#define MAKE_OP_SINGLE(ch1) (ch1)
-
-#define DEFAULT_STRING_BUFFER 65536
-
-using namespace std;
-
-struct Lexer
-{
-    explicit Lexer()
-    {
-        SetupTokenMaps();
-    }
-
-    enum Token
-    {
-        //status tokens
-        tok_eof = -10000,
-        tok_error,
-
-        //keywords
-#define DEF_KEYWORD(keyword) tok_##keyword,
-#include "keywords.h"
-#undef DEF_KEYWORD
-
-        //others
-        tok_identifier, //[a-zA-Z_][a-zA-Z0-9_]
-        tok_number, //(0x[0-9a-fA-F]+)|([0-9]+)
-        tok_stringlit, //"([^\\"]|\\([\\"'?abfnrtv0]|x[0-9a-fA-f]{2}))*"
-        tok_charlit, //'([^\\]|\\([\\"'?abfnrtv0]|x[0-9a-fA-f]{2}))'
-
-        //operators
-#define DEF_OP_TRIPLE(enumval, ch1, ch2, ch3) tok_##enumval,
-#define DEF_OP_DOUBLE(enumval, ch1, ch2) tok_##enumval,
-#define DEF_OP_SINGLE(enumval, ch1) tok_##enumval,
-#include "operators.h"
-#undef DEF_OP_TRIPLE
-#undef DEF_OP_DOUBLE
-#undef DEF_OP_SINGLE
-    };
-
-    vector<uint8_t> Input;
-    size_t Index = 0;
-    string Error;
-    vector<String> Warnings;
-
-    //lexer state
-    string IdentifierStr;
-    uint64_t NumberVal = 0;
-    bool IsHexNumberVal = false;
-    string StringLit;
-    string NumStr;
-    char CharLit = '\0';
-    int LastChar = ' ';
-    size_t CurLine = 0;
-    size_t LineIndex = 0;
-
-    static void clearReserve(string & str, size_t reserve = DEFAULT_STRING_BUFFER)
-    {
-        str.clear();
-        str.reserve(reserve);
-    }
-
-    static void appendCh(string & str, char ch)
-    {
-        str.resize(str.size() + 1);
-        str[str.size() - 1] = ch;
-    }
-
-    void ResetLexerState()
-    {
-        Input.clear();
-        Input.reserve(1024 * 1024);
-        Index = 0;
-        Error.clear();
-        Warnings.clear();
-        clearReserve(IdentifierStr);
-        NumberVal = 0;
-        IsHexNumberVal = false;
-        clearReserve(StringLit);
-        clearReserve(NumStr, 16);
-        CharLit = '\0';
-        LastChar = ' ';
-        CurLine = 0;
-        LineIndex = 0;
-    }
-
-    unordered_map<string, Token> KeywordMap;
-    unordered_map<Token, string> ReverseTokenMap;
-    unordered_map<int, Token> OpTripleMap;
-    unordered_map<int, Token> OpDoubleMap;
-    unordered_map<int, Token> OpSingleMap;
-
-    void SetupTokenMaps()
-    {
-        //setup keyword map
-#define DEF_KEYWORD(keyword) KeywordMap[#keyword] = tok_##keyword;
-#include "keywords.h"
-#undef DEF_KEYWORD
-
-        //setup token maps
-#define DEF_OP_TRIPLE(enumval, ch1, ch2, ch3) OpTripleMap[MAKE_OP_TRIPLE(ch1, ch2, ch3)] = tok_##enumval;
-#define DEF_OP_DOUBLE(enumval, ch1, ch2) OpDoubleMap[MAKE_OP_DOUBLE(ch1, ch2)] = tok_##enumval;
-#define DEF_OP_SINGLE(enumval, ch1) OpSingleMap[MAKE_OP_SINGLE(ch1)] = tok_##enumval;
-#include "operators.h"
-#undef DEF_OP_TRIPLE
-#undef DEF_OP_DOUBLE
-#undef DEF_OP_SINGLE
-
-        //setup reverse token maps
-#define DEF_KEYWORD(keyword) ReverseTokenMap[tok_##keyword] = #keyword;
-#include "keywords.h"
-#undef DEF_KEYWORD
-
-#define DEF_OP_TRIPLE(enumval, ch1, ch2, ch3) ReverseTokenMap[tok_##enumval] = string({ch1, ch2, ch3});
-#define DEF_OP_DOUBLE(enumval, ch1, ch2) ReverseTokenMap[tok_##enumval] = string({ch1, ch2});
-#define DEF_OP_SINGLE(enumval, ch1) ReverseTokenMap[tok_##enumval] = string({ch1});
-#include "operators.h"
-#undef DEF_OP_TRIPLE
-#undef DEF_OP_DOUBLE
-#undef DEF_OP_SINGLE
-    }
-
-    Token ReportError(const String & error)
-    {
-        Error = error;
-        return tok_error;
-    }
-
-    void ReportWarning(const String & warning)
-    {
-        Warnings.push_back(warning);
-    }
-
-    String TokString(int tok)
-    {
-        switch (Token(tok))
-        {
-        case tok_eof: return "tok_eof";
-        case tok_error: return StringUtils::sprintf("error(line %d, col %d, \"%s\")", CurLine + 1, LineIndex, Error.c_str());
-        case tok_identifier: return IdentifierStr;
-        case tok_number: return StringUtils::sprintf(IsHexNumberVal ? "0x%llX" : "%llu", NumberVal);
-        case tok_stringlit: return StringUtils::sprintf("\"%s\"", StringUtils::Escape(StringLit).c_str());
-        case tok_charlit:
-        {
-            String s;
-            s = CharLit;
-            return StringUtils::sprintf("'%s'", StringUtils::Escape(s).c_str());
-        }
-        default:
-        {
-            auto found = ReverseTokenMap.find(Token(tok));
-            if (found != ReverseTokenMap.end())
-                return found->second;
-            return "<INVALID TOKEN>";
-        }
-        }
-    }
-
-    int PeekChar(size_t distance = 0)
-    {
-        if (Index + distance >= Input.size())
-            return EOF;
-        auto ch = Input[Index + distance];
-        if (ch == '\0')
-        {
-            ReportWarning(StringUtils::sprintf("\\0 character in file data"));
-            return PeekChar(distance + 1);
-        }
-        return ch;
-    }
-
-    int ReadChar()
-    {
-        if (Index == Input.size())
-            return EOF;
-        auto ch = Input[Index++];
-        LineIndex++;
-        if (ch == '\0')
-        {
-            ReportWarning(StringUtils::sprintf("\\0 character in file data"));
-            return ReadChar();
-        }
-        return ch;
-    }
-
-    bool CheckString(const string & expected)
-    {
-        for (size_t i = 0; i < expected.size(); i++)
-        {
-            auto ch = PeekChar(i);
-            if (ch == EOF)
-                return false;
-            if (ch != uint8_t(expected[i]))
-                return false;
-        }
-        Index += expected.size();
-        return true;
-    }
-
-    int NextChar()
-    {
-        return LastChar = ReadChar();
-    }
-
-    void SignalNextLine()
-    {
-        CurLine++;
-        LineIndex = 0;
-    }
-
-    static const char* ConvertNumber(const char* str, uint64_t & result, int radix)
-    {
-        errno = 0;
-        char* end;
-        result = strtoull(str, &end, radix);
-        if (!result && end == str)
-            return "not a number";
-        if (result == ULLONG_MAX && errno)
-            return "does not fit";
-        if (*end)
-            return "str not completely consumed";
-        return nullptr;
-    }
-
-    int GetToken()
-    {
-        //skip whitespace
-        while (isspace(LastChar))
-        {
-            if (LastChar == '\n')
-                SignalNextLine();
-            NextChar();
-        }
-
-        //skip \\[\r\n]
-        if (LastChar == '\\' && (PeekChar() == '\r' || PeekChar() == '\n'))
-        {
-            NextChar();
-            return GetToken();
-        }
-
-        //character literal
-        if (LastChar == '\'')
-        {
-            string charLit;
-            while (true)
-            {
-                NextChar();
-                if (LastChar == EOF) //end of file
-                    return ReportError("unexpected end of file in character literal (1)");
-                if (LastChar == '\r' || LastChar == '\n')
-                    return ReportError("unexpected newline in character literal (1)");
-                if (LastChar == '\'') //end of character literal
-                {
-                    if (charLit.length() != 1)
-                        return ReportError(StringUtils::sprintf("invalid character literal '%s'", charLit.c_str()));
-                    CharLit = charLit[0];
-                    NextChar();
-                    return tok_charlit;
-                }
-                if (LastChar == '\\') //escape sequence
-                {
-                    NextChar();
-                    if (LastChar == EOF)
-                        return ReportError("unexpected end of file in character literal (2)");
-                    if (LastChar == '\r' || LastChar == '\n')
-                        return ReportError("unexpected newline in character literal (2)");
-                    if (LastChar == '\'' || LastChar == '\"' || LastChar == '?' || LastChar == '\\')
-                        LastChar = LastChar;
-                    else if (LastChar == 'a')
-                        LastChar = '\a';
-                    else if (LastChar == 'b')
-                        LastChar = '\b';
-                    else if (LastChar == 'f')
-                        LastChar = '\f';
-                    else if (LastChar == 'n')
-                        LastChar = '\n';
-                    else if (LastChar == 'r')
-                        LastChar = '\r';
-                    else if (LastChar == 't')
-                        LastChar = '\t';
-                    else if (LastChar == 'v')
-                        LastChar = '\v';
-                    else if (LastChar == '0')
-                        LastChar = '\0';
-                    else if (LastChar == 'x') //\xHH
-                    {
-                        auto ch1 = NextChar();
-                        auto ch2 = NextChar();
-                        if (isxdigit(ch1) && isxdigit(ch2))
-                        {
-                            char byteStr[3] = "";
-                            byteStr[0] = ch1;
-                            byteStr[1] = ch2;
-                            uint64_t hexData;
-                            auto error = ConvertNumber(byteStr, hexData, 16);
-                            if (error)
-                                return ReportError(StringUtils::sprintf("ConvertNumber failed (%s) for hex sequence \"\\x%c%c\" in character literal", error, ch1, ch2));
-                            LastChar = hexData & 0xFF;
-                        }
-                        else
-                            return ReportError(StringUtils::sprintf("invalid hex sequence \"\\x%c%c\" in character literal", ch1, ch2));
-                    }
-                    else
-                        return ReportError(StringUtils::sprintf("invalid escape sequence \"\\%c\" in character literal", LastChar));
-                }
-                charLit += LastChar;
-            }
-        }
-
-        //string literal
-        if (LastChar == '\"')
-        {
-            StringLit.clear();
-            while (true)
-            {
-                NextChar();
-                if (LastChar == EOF) //end of file
-                    return ReportError("unexpected end of file in string literal (1)");
-                if (LastChar == '\r' || LastChar == '\n')
-                    return ReportError("unexpected newline in string literal (1)");
-                if (LastChar == '\"') //end of string literal
-                {
-                    NextChar();
-                    return tok_stringlit;
-                }
-                if (LastChar == '\\') //escape sequence
-                {
-                    NextChar();
-                    if (LastChar == EOF)
-                        return ReportError("unexpected end of file in string literal (2)");
-                    if (LastChar == '\r' || LastChar == '\n')
-                        return ReportError("unexpected newline in string literal (2)");
-                    if (LastChar == '\'' || LastChar == '\"' || LastChar == '?' || LastChar == '\\')
-                        LastChar = LastChar;
-                    else if (LastChar == 'a')
-                        LastChar = '\a';
-                    else if (LastChar == 'b')
-                        LastChar = '\b';
-                    else if (LastChar == 'f')
-                        LastChar = '\f';
-                    else if (LastChar == 'n')
-                        LastChar = '\n';
-                    else if (LastChar == 'r')
-                        LastChar = '\r';
-                    else if (LastChar == 't')
-                        LastChar = '\t';
-                    else if (LastChar == 'v')
-                        LastChar = '\v';
-                    else if (LastChar == '0')
-                        LastChar = '\0';
-                    else if (LastChar == 'x') //\xHH
-                    {
-                        auto ch1 = NextChar();
-                        auto ch2 = NextChar();
-                        if (isxdigit(ch1) && isxdigit(ch2))
-                        {
-                            char byteStr[3] = "";
-                            byteStr[0] = ch1;
-                            byteStr[1] = ch2;
-                            uint64_t hexData;
-                            auto error = ConvertNumber(byteStr, hexData, 16);
-                            if (error)
-                                return ReportError(StringUtils::sprintf("ConvertNumber failed (%s) for hex sequence \"\\x%c%c\" in string literal", error, ch1, ch2));
-                            LastChar = hexData & 0xFF;
-                        }
-                        else
-                            return ReportError(StringUtils::sprintf("invalid hex sequence \"\\x%c%c\" in string literal", ch1, ch2));
-                    }
-                    else
-                        return ReportError(StringUtils::sprintf("invalid escape sequence \"\\%c\" in string literal", LastChar));
-                }
-                appendCh(StringLit, LastChar);
-            }
-        }
-
-        //identifier/keyword
-        if (isalpha(LastChar) || LastChar == '_') //[a-zA-Z_]
-        {
-            IdentifierStr = LastChar;
-            NextChar();
-            while (isalnum(LastChar) || LastChar == '_') //[0-9a-zA-Z_]
-            {
-                appendCh(IdentifierStr, LastChar);
-                NextChar();
-            }
-
-            //keywords
-            auto found = KeywordMap.find(IdentifierStr);
-            if (found != KeywordMap.end())
-                return found->second;
-
-            return tok_identifier;
-        }
-
-        //hex numbers
-        if (LastChar == '0' && PeekChar() == 'x') //0x
-        {
-            NextChar(); //consume the 'x'
-            NumStr.clear();
-
-            while (isxdigit(NextChar())) //[0-9a-fA-F]*
-                appendCh(NumStr, LastChar);
-
-            if (!NumStr.length()) //check for error condition
-                return ReportError("no hex digits after \"0x\" prefix");
-
-            auto error = ConvertNumber(NumStr.c_str(), NumberVal, 16);
-            if (error)
-                return ReportError(StringUtils::sprintf("ConvertNumber failed (%s) on hexadecimal number", error));
-            IsHexNumberVal = true;
-            return tok_number;
-        }
-        if (isdigit(LastChar)) //[0-9]
-        {
-            NumStr = LastChar;
-
-            while (isdigit(NextChar())) //[0-9]*
-                NumStr += LastChar;
-
-            auto error = ConvertNumber(NumStr.c_str(), NumberVal, 10);
-            if (error)
-                return ReportError(StringUtils::sprintf("ConvertNumber failed (%s) on decimal number", error));
-            IsHexNumberVal = false;
-            return tok_number;
-        }
-
-        //comments
-        if (LastChar == '/' && PeekChar() == '/') //line comment
-        {
-            do
-            {
-                if (LastChar == '\n')
-                    SignalNextLine();
-                NextChar();
-            } while (!(LastChar == EOF || LastChar == '\n'));
-
-            return GetToken(); //interpret the next line
-        }
-        if (LastChar == '/' && PeekChar() == '*') //block comment
-        {
-            do
-            {
-                if (LastChar == '\n')
-                    SignalNextLine();
-                NextChar();
-            } while (!(LastChar == EOF || LastChar == '*' && PeekChar() == '/'));
-
-            if (LastChar == EOF) //unexpected end of file
-            {
-                LineIndex++;
-                return ReportError("unexpected end of file in block comment");
-            }
-
-            NextChar();
-            NextChar();
-            return GetToken(); //get the next non-comment token
-        }
-
-        //operators
-        auto opFound = OpTripleMap.find(MAKE_OP_TRIPLE(LastChar, PeekChar(), PeekChar(1)));
-        if (opFound != OpTripleMap.end())
-        {
-            NextChar();
-            NextChar();
-            NextChar();
-            return opFound->second;
-        }
-        opFound = OpDoubleMap.find(MAKE_OP_DOUBLE(LastChar, PeekChar()));
-        if (opFound != OpDoubleMap.end())
-        {
-            NextChar();
-            NextChar();
-            return opFound->second;
-        }
-        opFound = OpSingleMap.find(MAKE_OP_SINGLE(LastChar));
-        if (opFound != OpSingleMap.end())
-        {
-            NextChar();
-            return opFound->second;
-        }
-
-        //end of file
-        if (LastChar == EOF)
-            return tok_eof;
-
-        //unknown character
-        return ReportError(StringUtils::sprintf("unexpected character \'%c\'", LastChar));
-    }
-
-    bool ReadInputFile(const string & filename)
-    {
-        ResetLexerState();
-        return FileHelper::ReadAllData(filename, Input);
-    }
-
-    bool TestLex(const function<void(const string & line)> & lexEnum, bool output = true)
-    {
-        size_t line = 0;
-        if (output)
-            lexEnum("1: ");
-        int tok;
-        string toks;
-        clearReserve(toks);
-        char newlineText[128] = "";
-        do
-        {
-            tok = GetToken();
-            if (!output)
-                continue;
-            toks.clear();
-            while (line < CurLine)
-            {
-                line++;
-                sprintf_s(newlineText, "\n%d: ", line + 1);
-                toks.append(newlineText);
-            }
-            toks.append(TokString(tok));
-            appendCh(toks, ' ');
-            lexEnum(toks);
-        } while (tok != tok_eof && tok != tok_error);
-        if (tok != tok_error && tok != tok_eof)
-            tok = ReportError("lexer did not finish at the end of the file");
-        for (const auto & warning : Warnings)
-            if (output)
-                lexEnum("\nwarning: " + warning);
-        return tok != tok_error;
-    }
-};
-
-bool TestLexer(Lexer & lexer, const string & filename)
+bool TestLexer(Lexer & lexer, const std::string & filename)
 {
     if (!lexer.ReadInputFile("tests\\" + filename))
     {
         printf("failed to read \"%s\"\n", filename.c_str());
         return false;
     }
-    string actual;
-    Lexer::clearReserve(actual);
-    auto success = lexer.TestLex([&](const string & line)
+    std::string actual;
+    actual.reserve(65536);
+    auto success = lexer.Test([&](const std::string & line)
     {
         actual.append(line);
     });
-    string expected;
-    if (FileHelper::ReadAllText("tests\\exp_lex\\" + filename, expected))
+    std::string expected;
+    if (FileHelper::ReadAllText("tests\\exp_lex\\" + filename, expected) && expected == actual)
     {
-        if (expected == actual)
-        {
-            printf("lexer test for \"%s\" success!\n", filename.c_str());
-            return true;
-        }
+        printf("lexer test for \"%s\" success!\n", filename.c_str());
+        return true;
     }
     if (success)
         return true;
@@ -571,14 +31,14 @@ bool TestLexer(Lexer & lexer, const string & filename)
     return false;
 }
 
-bool DebugLexer(Lexer & lexer, const string & filename, bool output)
+bool DebugLexer(Lexer & lexer, const std::string & filename, bool output)
 {
     if (!lexer.ReadInputFile("tests\\" + filename))
     {
         printf("failed to read \"%s\"\n", filename.c_str());
         return false;
     }
-    auto success = lexer.TestLex([](const string & line)
+    auto success = lexer.Test([](const std::string & line)
     {
         printf("%s", line.c_str());
     }, output);
@@ -587,16 +47,16 @@ bool DebugLexer(Lexer & lexer, const string & filename, bool output)
     return success;
 }
 
-void GenerateExpected(Lexer & lexer, const string & filename)
+void GenerateExpected(Lexer & lexer, const std::string & filename)
 {
     if (!lexer.ReadInputFile("tests\\" + filename))
     {
         printf("failed to read \"%s\"\n", filename.c_str());
         return;
     }
-    string actual;
-    Lexer::clearReserve(actual);
-    lexer.TestLex([&](const string & line)
+    std::string actual;
+    actual.reserve(65536);
+    lexer.Test([&](const std::string & line)
     {
         actual.append(line);
     });