/home/master/UCL/VisualizationLibrary/src/vlCore/VLTTokenizer.cpp

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/*  Visualization Library                                                             */
/*  http://visualizationlibrary.org                                                   */
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#include <vlCore/VLTTokenizer.hpp>
#include <vlCore/Log.hpp>
#include <vlCore/Say.hpp>
#include <ctime>

using namespace vl;

bool VLTTokenizer::getToken(VLTToken& token)
{
  token.mType = VLTToken::TOKEN_ERROR;
  /*token.mString.resize(0);*/

  // Must be done before StringTurbo is declared
  if (mRawtextBlock)
    return getRawtextBlock(token);

  struct StringTurbo
  {
    inline StringTurbo(std::string* str): mString(str)
    {
      mPosition = 0;
    }
    
    inline ~StringTurbo()
    {
      mBuffer[mPosition] = '\0';
      *mString = mBuffer;
    }

    inline void push_back(const char& ch)
    {
      mBuffer[mPosition++] = ch;
    }

    inline void operator=(const char& ch)
    {
      mBuffer[0] = ch;
      mPosition = 1;
    }

    inline void operator=(const char* s)
    {
      int len = strlen(s);
      memcpy( mBuffer, s, len);
      mPosition = len;
    }

    inline bool operator==(const char* str)
    {
      size_t len = strlen(str);
      if (len != mPosition)
        return false;
      else
        return memcmp(mBuffer, str, len) == 0;
    }

    char mBuffer[1024*4];
    size_t mPosition;
    std::string* mString;
  } string_turbo(&token.mString);

  // read chars skipping spaces
  char ch1=0, ch2=0;
  do 
  {
    if (!readTextChar(ch1))
    {
      token.mType = VLTToken::TOKEN_EOF;
      return true;
    }

    if (ch1 == '\n')
      ++mLineNumber;
    else
    // eat comments
    if (ch1 == '/')
    {
      if(readTextChar(ch2))
      {
        if (ch2 == '/') // single line comment
        {
          // eat everything till the end of the line
          for(ch1 = 0; readTextChar(ch1) && ch1 != '\n'; )
          {
            // eat everything
          }
          if (ch1 == '\n')
            ++mLineNumber;
        }
        else
        if (ch2 == '*') // multi line comment
        {
          // eat everything till the end of the line
          while(readTextChar(ch1))
          {
            if (ch1 == '*' && readTextChar(ch2) && ch2 == '/')
            {
              ch1 = '\n'; // pretend it's a space to stay in the loop
              break;
            }
            // eat everything
            if (ch1 == '\n')
              ++mLineNumber;
          }
        }
        else
        {
          Log::error( Say("Line %n : unexpected character '%c' after '/'.\n") << mLineNumber << ch2 );
          return false;
        }
      }
      else
      {
        Log::error( Say("Line %n : unexpected end of file in comment.\n") << mLineNumber);
        return false;
      }
      continue;
    }

  } while(ch1 == ' ' || ch1 == '\t' || ch1 == '\n');

  switch(ch1)
  {
  case '(':
    token.mType = VLTToken::LeftRoundBracket;
    string_turbo = "(";
    return true;
    
  case ')':
    token.mType = VLTToken::RightRoundBracket;
    string_turbo = ")";
    return true;

  case '[':
    token.mType = VLTToken::LeftSquareBracket;
    string_turbo = "[";
    return true;
    
  case ']':
    token.mType = VLTToken::RightSquareBracket;
    string_turbo = "]";
    return true;

  case '{':
    if(readTextChar(ch2) && ch2 == '<')
    {
      // actual data starts at the next new line
      // eat all the spaces until the end of the current line
      while(ch2 != '\n' && readTextChar(ch2)) 
      { 
        switch(ch2)
        {
        case '\f':
        case '\b':
        case '\v':
        case '\t':
        case ' ':
          continue;

        case '\n':
          ++mLineNumber;
          break;

        default:
          string_turbo = ch2;
          return false;
        }
      }

      if (ch2 == '\n')
      {
        token.mType = VLTToken::LeftFancyBracket;
        string_turbo = "{<";
        mRawtextBlock = true;
        return true;
      }
      else
      {
        string_turbo = ch2;
        return false;
      }
    }
    else
    {
      token.mType = VLTToken::LeftCurlyBracket;
      string_turbo = "{";
      if(!isEndOfFile())
        ungetToken(ch2);
    }
    return true;

  case '}':
    token.mType = VLTToken::RightCurlyBracket;
    string_turbo = "}";
    return true;

  case '>':
    if(readTextChar(ch2))
    {
      if(ch2 == '}')
      {
        token.mType = VLTToken::RightFancyBracket;
        string_turbo = ">}";
        return true;
      }
      else
      {
        Log::error( Say("Line %n : expected '}' instead of '%c' after '>'.\n") << mLineNumber << ch2 );
        return false;
      }
    }
    else
    {
        Log::error( Say("Line %n : unexpected end of file.\n") << mLineNumber );
        return false;
    }

  case '=':
    token.mType = VLTToken::Equals; 
    string_turbo = "=";
    return true;

  case '<':
    string_turbo = "<";
    while(readTextChar(ch1) && ch1 != '>')
    {
      if ( (ch1 >= 'a' && ch1 <= 'z') || (ch1 >= 'A' && ch1 <= 'Z') || (ch1 >= '0' && ch1 <= '9') || ch1 == '_' || ch1 == ':' )
        string_turbo.push_back(ch1);
      else
      {
        Log::error( Say("Line %n : unexpected character '%c'.\n") << mLineNumber << ch1 );
        return false;
      }
    }
    string_turbo.push_back('>');
    if (isEndOfFile())
    {
      Log::error( Say("Line %n : unexpected end of file while reading object header.\n") << mLineNumber );
      return false;
    }
    token.mType = VLTToken::TagHeader;
    return true;

  case '#':
    string_turbo = "#";
    while(readTextChar(ch1))
    {
      if ( (ch1 >= 'a' && ch1 <= 'z') || (ch1 >= 'A' && ch1 <= 'Z') || (ch1 >= '0' && ch1 <= '9') || ch1 == '_' )
        string_turbo.push_back(ch1);
      else
      {
        ungetToken(ch1);
        break;
      }
    }
    if (string_turbo == "#_")
    {
      Log::error( Say("Line %n : illegal id '#_' found.\n") << mLineNumber );
      return false;
    }
    token.mType = VLTToken::ID;
    return true;

  case '"':
    while(readTextChar(ch1))
    {
      // end string
      if (ch1 == '"')
        break;
      else
      // return found before end of string
      if (ch1 == '\n')
      {
        Log::error( Say("Line %n : end of line found before end of string, did you forget a \"?.\n") << mLineNumber );
        return false;
      }
      else
      // escape sequences
      if (ch1 == '\\' && readTextChar(ch2))
      {
        if (ch2 == '"')
          ch1 = '"';
        else
        if (ch2 == '\\')
          ch1 = '\\';
        else
        if (ch2 == 'b')
          ch1 = '\b';
        else
        if (ch2 == 'f')
          ch1 = '\f';
        else
        if (ch2 == 'r')
          ch1 = '\r';
        else
        if (ch2 == 'n')
          ch1 = '\n';
        else
        if (ch2 == 't')
          ch1 = '\t';
        else
          ungetToken(ch2);
        string_turbo.push_back(ch1);
      }
      else
      // accept everyhing else
        string_turbo.push_back(ch1);
    }
    if (isEndOfFile())
    {
      Log::error( Say("Line %n : end of file found before end of string, did you forget a \"?.\n") << mLineNumber );
      return false;
    }
    else
    {
      token.mType = VLTToken::String;
      return true;
    }

  default:
    // identifier
    if ( (ch1 >= 'a' && ch1 <= 'z') || (ch1 >= 'A' && ch1 <= 'Z') || ch1 == '_' )
    {
      string_turbo.push_back(ch1);
      while(readTextChar(ch1))
      {
        if ( (ch1 >= 'a' && ch1 <= 'z') || (ch1 >= 'A' && ch1 <= 'Z') || (ch1 >= '0' && ch1 <= '9') || ch1 == '_' )
          string_turbo.push_back(ch1);
        else
        {
          ungetToken(ch1);
          break;
        }
      }
      if (string_turbo == "_")
      {
        Log::error( Say("Line %n : unexpected character '_'.\n") << mLineNumber );
        return false;
      }
      else
      {
        // check if it's a boolean
        if (string_turbo == "true" || string_turbo == "false")
          token.mType = VLTToken::Boolean;
        else
          token.mType = VLTToken::Identifier;
        return true;
      }
    }
    else
    // Integer / real
    //
    // ACCEPTED:
    // 123
    // +123.123E+10 -123.123e-10
    // +123
    // +.123
    // 0.123
    // 123.123
    //
    // REJECTED:
    // 01234
    // 01.234
    // 123.
    // 123.123E
    // 123.123e+
    if ( (ch1 >= '0' && ch1 <= '9') || ch1 == '.' || ch1 == '+' || ch1 == '-' )
    {
      token.mType = VLTToken::TOKEN_ERROR;
      string_turbo.push_back(ch1);

      enum { sZERO, sPLUS_MINUS, sINT, sFRAC, sPOINT, sE, sPLUS_MINUS_EXP, sEXP } state = sINT;

      if ( ch1 >= '1' && ch1 <= '9' )
        state = sINT;
      else
      if (ch1 == '0')
        state = sZERO;
      else
      if (ch1 == '.')
        state = sPOINT;
      else
      if (ch1 == '+' || ch1 == '-')
        state = sPLUS_MINUS;

      while(readTextChar(ch1))
      {
        switch(state)
        {
        // if starting with 0 must be 0.0-9
        case sZERO:
          if (ch1 == '.')
          {
            string_turbo.push_back(ch1);
            state = sPOINT;
          }
          else
          {
            token.mType = VLTToken::Integer;
            ungetToken(ch1);
            return true;
          }
          break;

        case sPLUS_MINUS:
          if (ch1 == '0')
          {
            string_turbo.push_back(ch1);
            state = sZERO;
          }
          else
          if (ch1 >= '1' && ch1 <= '9')
          {
            string_turbo.push_back(ch1);
            state = sINT;
          }
          else
          if (ch1 == '.')
          {
            string_turbo.push_back(ch1);
            state = sPOINT;
          }
          else
          {
            Log::error( Say("Line %n :unexpected character '%c'.\n") << mLineNumber << ch1 );
            return false;
          }
          break;

        case sINT:
          if (ch1 >= '0' && ch1 <= '9')
            string_turbo.push_back(ch1);
          else
          if (ch1 == '.')
          {
            string_turbo.push_back(ch1);
            state = sPOINT;
          }
          else
          {
            token.mType = VLTToken::Integer;
            ungetToken(ch1);
            return true;
          }
          break;

        case sPOINT:
          if (ch1 >= '0' && ch1 <= '9')
          {
            string_turbo.push_back(ch1);
            state = sFRAC;
          }
          else
          {
            Log::error( Say("Line %n :unexpected character '%c'.\n") << mLineNumber << ch1 );
            return false;
          }
          break;

        case sFRAC:
          if (ch1 >= '0' && ch1 <= '9')
            string_turbo.push_back(ch1);
          else
          if (ch1 == 'E' || ch1 == 'e')
          {
            string_turbo.push_back(ch1);
            state = sE;
          }
          else
          {
            token.mType = VLTToken::real;
            ungetToken(ch1);
            return true;
          }
          break;

        case sE:
          if (ch1 == '+' || ch1 == '-')
          {
            string_turbo.push_back(ch1);
            state = sPLUS_MINUS_EXP;
          }
          else
          {
            Log::error( Say("Line %n :unexpected character '%c'.\n") << mLineNumber << ch1 );
            return false;
          }
          break;

        case sPLUS_MINUS_EXP:
          if (ch1 >= '0' && ch1 <= '9')
          {
            string_turbo.push_back(ch1);
            state = sEXP;
          }
          else
          {
            Log::error( Say("Line %n :unexpected character '%c'.\n") << mLineNumber << ch1 );
            return false;
          }
          break;

        case sEXP:
          if (ch1 >= '0' && ch1 <= '9')
            string_turbo.push_back(ch1);
          else
          {
            token.mType = VLTToken::real;
            ungetToken(ch1);
            return true;
          }
          break;
        }
      }
      // reached TOKEN_EOF in the middle of the parsing so we check where we were, note that it cannot be a Integer or a real
      if (state == sINT)
      {
        token.mType = VLTToken::Integer;
        return true;
      }
      else
      if (state == sFRAC || state == sEXP)
      {
        token.mType = VLTToken::real;
        return true;
      }
      else
        return false;
    }
    else
    {
      Log::error( Say("Line %n : unexpected character '%c'.\n") << mLineNumber << ch1 );
      return false;
    }
  }
}
//-----------------------------------------------------------------------------
bool VLTTokenizer::getRawtextBlock(VLTToken& token)
{
  mRawtextBlock = false;

  token.mType = VLTToken::TOKEN_ERROR;
  token.mString.resize(0);

  char ch =0;
  while(readTextChar(ch))
  {
    if (ch == '\n')
      ++mLineNumber;

    if (ch == '>')
    {
      // check for rawtext block end >}
      char ch2 = 0;
      if (readTextChar(ch2))
      {
        if(ch2 == '}')
        {
          // check if it was escaped
          if (!token.mString.empty() && token.mString[ token.mString.size() - 1 ] == '\\')
          {
            token.mString.resize( token.mString.size() - 1 );
            token.mString += ">}";
            continue;
          }
          else
          {
            token.mType = VLTToken::RawtextBlock;
            ungetToken('}');
            ungetToken('>');
            return true;
          }
        }
        else
          ungetToken(ch2);
      }
    }
    
    token.mString.push_back(ch);
  }

  return false;
}
//-----------------------------------------------------------------------------