intellij-sdk-code-samples/idea-flex.skeleton

  /** initial size of the lookahead buffer */
--- private static final int ZZ_BUFFERSIZE = ...;

  /** lexical states */
---  lexical states, charmap

  /* error codes */
  private static final int ZZ_UNKNOWN_ERROR = 0;
  private static final int ZZ_NO_MATCH = 1;
  private static final int ZZ_PUSHBACK_2BIG = 2;
  private static final char[] EMPTY_BUFFER = new char[0];
  private static final int YYEOF = -1;
  private static java.io.Reader zzReader = null; // Fake

  /* error messages for the codes above */
  private static final String ZZ_ERROR_MSG[] = {
    "Unkown internal scanner error",
    "Error: could not match input",
    "Error: pushback value was too large"
  };

--- isFinal list
  /** the current state of the DFA */
  private int zzState;

  /** the current lexical state */
  private int zzLexicalState = YYINITIAL;

  /** this buffer contains the current text to be matched and is
      the source of the yytext() string */
  private CharSequence zzBuffer = "";

  /** this buffer may contains the current text array to be matched when it is cheap to acquire it */
  private char[] zzBufferArray;

  /** the textposition at the last accepting state */
  private int zzMarkedPos;

  /** the textposition at the last state to be included in yytext */
  private int zzPushbackPos;

  /** the current text position in the buffer */
  private int zzCurrentPos;

  /** startRead marks the beginning of the yytext() string in the buffer */
  private int zzStartRead;

  /** endRead marks the last character in the buffer, that has been read
      from input */
  private int zzEndRead;

  /**
   * zzAtBOL == true <=> the scanner is currently at the beginning of a line
   */
  private boolean zzAtBOL = true;

  /** zzAtEOF == true <=> the scanner is at the EOF */
  private boolean zzAtEOF;

--- user class code

--- constructor declaration

  public final int getTokenStart(){
    return zzStartRead;
  }

  public final int getTokenEnd(){
    return getTokenStart() + yylength();
  }

  public void reset(CharSequence buffer, int start, int end,int initialState){
    zzBuffer = buffer;
    zzBufferArray = com.intellij.util.text.CharArrayUtil.fromSequenceWithoutCopying(buffer);
    zzCurrentPos = zzMarkedPos = zzStartRead = start;
    zzPushbackPos = 0;
    zzAtEOF  = false;
    zzAtBOL = true;
    zzEndRead = end;
    yybegin(initialState);
  }

  /**
   * Refills the input buffer.
   *
   * @return      <code>false</code>, iff there was new input.
   *
   * @exception   java.io.IOException  if any I/O-Error occurs
   */
  private boolean zzRefill() throws java.io.IOException {
    return true;
  }


  /**
   * Returns the current lexical state.
   */
  public final int yystate() {
    return zzLexicalState;
  }


  /**
   * Enters a new lexical state
   *
   * @param newState the new lexical state
   */
  public final void yybegin(int newState) {
    zzLexicalState = newState;
  }


  /**
   * Returns the text matched by the current regular expression.
   */
  public final CharSequence yytext() {
    return zzBuffer.subSequence(zzStartRead, zzMarkedPos);
  }


  /**
   * Returns the character at position <tt>pos</tt> from the
   * matched text.
   *
   * It is equivalent to yytext().charAt(pos), but faster
   *
   * @param pos the position of the character to fetch.
   *            A value from 0 to yylength()-1.
   *
   * @return the character at position pos
   */
  public final char yycharat(int pos) {
    return zzBufferArray != null ? zzBufferArray[zzStartRead+pos]:zzBuffer.charAt(zzStartRead+pos);
  }


  /**
   * Returns the length of the matched text region.
   */
  public final int yylength() {
    return zzMarkedPos-zzStartRead;
  }


  /**
   * Reports an error that occured while scanning.
   *
   * In a wellformed scanner (no or only correct usage of
   * yypushback(int) and a match-all fallback rule) this method
   * will only be called with things that "Can't Possibly Happen".
   * If this method is called, something is seriously wrong
   * (e.g. a JFlex bug producing a faulty scanner etc.).
   *
   * Usual syntax/scanner level error handling should be done
   * in error fallback rules.
   *
   * @param   errorCode  the code of the errormessage to display
   */
--- zzScanError declaration
    String message;
    try {
      message = ZZ_ERROR_MSG[errorCode];
    }
    catch (ArrayIndexOutOfBoundsException e) {
      message = ZZ_ERROR_MSG[ZZ_UNKNOWN_ERROR];
    }

--- throws clause
  }


  /**
   * Pushes the specified amount of characters back into the input stream.
   *
   * They will be read again by then next call of the scanning method
   *
   * @param number  the number of characters to be read again.
   *                This number must not be greater than yylength()!
   */
--- yypushback decl (contains zzScanError exception)
    if ( number > yylength() )
      zzScanError(ZZ_PUSHBACK_2BIG);

    zzMarkedPos -= number;
  }


--- zzDoEOF
  /**
   * Resumes scanning until the next regular expression is matched,
   * the end of input is encountered or an I/O-Error occurs.
   *
   * @return      the next token
   * @exception   java.io.IOException  if any I/O-Error occurs
   */
--- yylex declaration
    int zzInput;
    int zzAction;

    // cached fields:
    int zzCurrentPosL;
    int zzMarkedPosL;
    int zzEndReadL = zzEndRead;
    CharSequence zzBufferL = zzBuffer;
    char[] zzBufferArrayL = zzBufferArray;
    char [] zzCMapL = ZZ_CMAP;

--- local declarations

    while (true) {
      zzMarkedPosL = zzMarkedPos;

--- start admin (line, char, col count)
      zzAction = -1;

      zzCurrentPosL = zzCurrentPos = zzStartRead = zzMarkedPosL;

--- start admin (lexstate etc)

      zzForAction: {
        while (true) {

--- next input, line, col, char count, next transition, isFinal action
            zzAction = zzState;
            zzMarkedPosL = zzCurrentPosL;
--- line count update
          }

        }
      }

      // store back cached position
      zzMarkedPos = zzMarkedPosL;
--- char count update

--- actions
        default:
          if (zzInput == YYEOF && zzStartRead == zzCurrentPos) {
            zzAtEOF = true;
--- eofvalue
          }
          else {
--- no match
          }
      }
    }
  }

--- main

}