Lexer.java

/*
 * Copyright 2017 Michael Mackenzie High
 *
 * Licensed 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 com.mackenziehigh.sexpr.internal;

/* The following code was generated by JFlex 1.4.3 on 9/3/18, 9:32 PM */
/**
 * This class is a scanner generated by
 * <a href="http://www.jflex.de/">JFlex</a> 1.4.3
 * on 9/3/18, 9:32 PM from the specification file
 * <tt>Lexer.txt</tt>
 */
final class Lexer
{

    /**
     * This character denotes the end of file
     */
    public static final int YYEOF = -1;

    /**
     * initial size of the lookahead buffer
     */
    private static final int ZZ_BUFFERSIZE = 16384;

    /**
     * lexical states
     */
    public static final int YYINITIAL = 0;

    /**
     * ZZ_LEXSTATE[l] is the state in the DFA for the lexical state l
     * ZZ_LEXSTATE[l+1] is the state in the DFA for the lexical state l
     * at the beginning of a line
     * l is of the form l = 2*k, k a non negative integer
     */
    private static final int ZZ_LEXSTATE[] =
    {
        0,
        0
    };

    /**
     * Translates characters to character classes
     */
    private static final String ZZ_CMAP_PACKED
                                = "\11\0\1\10\1\7\2\0\1\7\22\0\1\10\1\0\1\3\1\6"
                                  + "\3\0\1\2\1\11\1\5\26\0\1\1\33\0\1\4\uffa3\0";

    /**
     * Translates characters to character classes
     */
    private static final char[] ZZ_CMAP = zzUnpackCMap(ZZ_CMAP_PACKED);

    /**
     * Translates DFA states to action switch labels.
     */
    private static final int[] ZZ_ACTION = zzUnpackAction();

    private static final String ZZ_ACTION_PACKED_0
                                = "\1\0\1\1\3\2\1\3\2\4\1\5\3\0\1\6"
                                  + "\2\0\1\7\1\0\1\10\1\11\1\6\1\7";

    private static int[] zzUnpackAction ()
    {
        int[] result = new int[21];
        int offset = 0;
        offset = zzUnpackAction(ZZ_ACTION_PACKED_0, offset, result);
        return result;
    }

    private static int zzUnpackAction (String packed,
                                       int offset,
                                       int[] result)
    {
        int i = 0;
        /* index in packed string  */
        int j = offset;
        /* index in unpacked array */
        int l = packed.length();
        while (i < l)
        {
            int count = packed.charAt(i++);
            int value = packed.charAt(i++);
            do
            {
                result[j++] = value;
            }
            while (--count > 0);
        }
        return j;
    }

    /**
     * Translates a state to a row index in the transition table
     */
    private static final int[] ZZ_ROWMAP = zzUnpackRowMap();

    private static final String ZZ_ROWMAP_PACKED_0
                                = "\0\0\0\12\0\24\0\36\0\50\0\62\0\74\0\62"
                                  + "\0\62\0\106\0\120\0\36\0\62\0\132\0\50\0\62"
                                  + "\0\144\0\62\0\62\0\36\0\50";

    private static int[] zzUnpackRowMap ()
    {
        int[] result = new int[21];
        int offset = 0;
        offset = zzUnpackRowMap(ZZ_ROWMAP_PACKED_0, offset, result);
        return result;
    }

    private static int zzUnpackRowMap (String packed,
                                       int offset,
                                       int[] result)
    {
        int i = 0;
        /* index in packed string  */
        int j = offset;
        /* index in unpacked array */
        int l = packed.length();
        while (i < l)
        {
            int high = packed.charAt(i++) << 16;
            result[j++] = high | packed.charAt(i++);
        }
        return j;
    }

    /**
     * The transition table of the DFA
     */
    private static final int[] ZZ_TRANS = zzUnpackTrans();

    private static final String ZZ_TRANS_PACKED_0
                                = "\1\2\1\3\1\4\1\5\1\2\1\6\1\7\2\10"
                                  + "\1\11\1\2\3\0\1\2\7\0\1\12\1\13\6\0"
                                  + "\2\14\1\15\1\14\1\16\5\14\3\17\1\20\1\21"
                                  + "\5\17\12\0\7\7\1\0\2\7\2\12\1\22\7\12"
                                  + "\3\13\1\23\6\13\2\14\1\24\1\14\1\16\5\14"
                                  + "\3\17\1\25\1\21\5\17";

    private static int[] zzUnpackTrans ()
    {
        int[] result = new int[110];
        int offset = 0;
        offset = zzUnpackTrans(ZZ_TRANS_PACKED_0, offset, result);
        return result;
    }

    private static int zzUnpackTrans (String packed,
                                      int offset,
                                      int[] result)
    {
        int i = 0;
        /* index in packed string  */
        int j = offset;
        /* index in unpacked array */
        int l = packed.length();
        while (i < l)
        {
            int count = packed.charAt(i++);
            int value = packed.charAt(i++);
            value--;
            do
            {
                result[j++] = value;
            }
            while (--count > 0);
        }
        return j;
    }


    /* 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;

    /* 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"
    };

    /**
     * ZZ_ATTRIBUTE[aState] contains the attributes of state <code>aState</code>
     */
    private static final int[] ZZ_ATTRIBUTE = zzUnpackAttribute();

    private static final String ZZ_ATTRIBUTE_PACKED_0
                                = "\1\0\4\1\1\11\1\1\2\11\3\0\1\11\2\0"
                                  + "\1\11\1\0\2\11\2\1";

    private static int[] zzUnpackAttribute ()
    {
        int[] result = new int[21];
        int offset = 0;
        offset = zzUnpackAttribute(ZZ_ATTRIBUTE_PACKED_0, offset, result);
        return result;
    }

    private static int zzUnpackAttribute (String packed,
                                          int offset,
                                          int[] result)
    {
        int i = 0;
        /* index in packed string  */
        int j = offset;
        /* index in unpacked array */
        int l = packed.length();
        while (i < l)
        {
            int count = packed.charAt(i++);
            int value = packed.charAt(i++);
            do
            {
                result[j++] = value;
            }
            while (--count > 0);
        }
        return j;
    }

    /**
     * the input device
     */
    private java.io.Reader zzReader;

    /**
     * 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 char zzBuffer[] = new char[ZZ_BUFFERSIZE];

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

    /**
     * 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;

    /**
     * number of newlines encountered up to the start of the matched text
     */
    private int yyline;

    /**
     * the number of characters up to the start of the matched text
     */
    private int yychar;

    /**
     * the number of characters from the last newline up to the start of the
     * matched text
     */
    private int yycolumn;

    /**
     * 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;

    /**
     * denotes if the user-EOF-code has already been executed
     */
    private boolean zzEOFDone;

    /* user code: */
    final LexerStack stack = new LexerStack();

    /**
     * Creates a new scanner
     * There is also a java.io.InputStream version of this constructor.
     *
     * @param in the java.io.Reader to read input from.
     */
    Lexer (java.io.Reader in)
    {
        this.zzReader = in;
    }

    /**
     * Creates a new scanner.
     * There is also java.io.Reader version of this constructor.
     *
     * @param in the java.io.Inputstream to read input from.
     */
    Lexer (java.io.InputStream in)
    {
        this(new java.io.InputStreamReader(in));
    }

    /**
     * Unpacks the compressed character translation table.
     *
     * @param packed the packed character translation table
     * @return the unpacked character translation table
     */
    private static char[] zzUnpackCMap (String packed)
    {
        char[] map = new char[0x10000];
        int i = 0;
        /* index in packed string  */
        int j = 0;
        /* index in unpacked array */
        while (i < 38)
        {
            int count = packed.charAt(i++);
            char value = packed.charAt(i++);
            do
            {
                map[j++] = value;
            }
            while (--count > 0);
        }
        return map;
    }

    /**
     * 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
    {

        /* first: make room (if you can) */
        if (zzStartRead > 0)
        {
            System.arraycopy(zzBuffer, zzStartRead,
                             zzBuffer, 0,
                             zzEndRead - zzStartRead);

            /* translate stored positions */
            zzEndRead -= zzStartRead;
            zzCurrentPos -= zzStartRead;
            zzMarkedPos -= zzStartRead;
            zzStartRead = 0;
        }

        /* is the buffer big enough? */
        if (zzCurrentPos >= zzBuffer.length)
        {
            /* if not: blow it up */
            char newBuffer[] = new char[zzCurrentPos * 2];
            System.arraycopy(zzBuffer, 0, newBuffer, 0, zzBuffer.length);
            zzBuffer = newBuffer;
        }

        /* finally: fill the buffer with new input */
        int numRead = zzReader.read(zzBuffer, zzEndRead,
                                    zzBuffer.length - zzEndRead);

        if (numRead > 0)
        {
            zzEndRead += numRead;
            return false;
        }
        // unlikely but not impossible: read 0 characters, but not at end of stream
        if (numRead == 0)
        {
            int c = zzReader.read();
            if (c == -1)
            {
                return true;
            }
            else
            {
                zzBuffer[zzEndRead++] = (char) c;
                return false;
            }
        }

        // numRead < 0
        return true;
    }

    /**
     * Closes the input stream.
     */
    public final void yyclose ()
            throws java.io.IOException
    {
        zzAtEOF = true;
        /* indicate end of file */
        zzEndRead = zzStartRead;
        /* invalidate buffer    */

        if (zzReader != null)
        {
            zzReader.close();
        }
    }

    /**
     * Resets the scanner to read from a new input stream.
     * Does not close the old reader.
     *
     * All internal variables are reset, the old input stream
     * <b>cannot</b> be reused (internal buffer is discarded and lost).
     * Lexical state is set to <tt>ZZ_INITIAL</tt>.
     *
     * @param reader the new input stream
     */
    public final void yyreset (java.io.Reader reader)
    {
        zzReader = reader;
        zzAtBOL = true;
        zzAtEOF = false;
        zzEOFDone = false;
        zzEndRead = zzStartRead = 0;
        zzCurrentPos = zzMarkedPos = 0;
        yyline = yychar = yycolumn = 0;
        zzLexicalState = YYINITIAL;
    }

    /**
     * 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 String yytext ()
    {
        return new String(zzBuffer, zzStartRead, zzMarkedPos - zzStartRead);
    }

    /**
     * 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 zzBuffer[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
     */
    private void zzScanError (int errorCode)
    {
        String message;
        try
        {
            message = ZZ_ERROR_MSG[errorCode];
        }
        catch (ArrayIndexOutOfBoundsException e)
        {
            message = ZZ_ERROR_MSG[ZZ_UNKNOWN_ERROR];
        }

        throw new Error(message);
    }

    /**
     * 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()!
     */
    public void yypushback (int number)
    {
        if (number > yylength())
        {
            zzScanError(ZZ_PUSHBACK_2BIG);
        }

        zzMarkedPos -= number;
    }

    /**
     * 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
     */
    public int yylex ()
            throws java.io.IOException
    {
        int zzInput;
        int zzAction;

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

        int[] zzTransL = ZZ_TRANS;
        int[] zzRowMapL = ZZ_ROWMAP;
        int[] zzAttrL = ZZ_ATTRIBUTE;

        while (true)
        {
            zzMarkedPosL = zzMarkedPos;

            boolean zzR = false;
            for (zzCurrentPosL = zzStartRead; zzCurrentPosL < zzMarkedPosL;
                 zzCurrentPosL++)
            {
                switch (zzBufferL[zzCurrentPosL])
                {
                    case '\u000B':
                    case '\u000C':
                    case '\u0085':
                    case '\u2028':
                    case '\u2029':
                        yyline++;
                        yycolumn = 0;
                        zzR = false;
                        break;
                    case '\r':
                        yyline++;
                        yycolumn = 0;
                        zzR = true;
                        break;
                    case '\n':
                        if (zzR)
                        {
                            zzR = false;
                        }
                        else
                        {
                            yyline++;
                            yycolumn = 0;
                        }
                        break;
                    default:
                        zzR = false;
                        yycolumn++;
                }
            }

            if (zzR)
            {
                // peek one character ahead if it is \n (if we have counted one line too much)
                boolean zzPeek;
                if (zzMarkedPosL < zzEndReadL)
                {
                    zzPeek = zzBufferL[zzMarkedPosL] == '\n';
                }
                else if (zzAtEOF)
                {
                    zzPeek = false;
                }
                else
                {
                    boolean eof = zzRefill();
                    zzEndReadL = zzEndRead;
                    zzMarkedPosL = zzMarkedPos;
                    zzBufferL = zzBuffer;
                    if (eof)
                    {
                        zzPeek = false;
                    }
                    else
                    {
                        zzPeek = zzBufferL[zzMarkedPosL] == '\n';
                    }
                }
                if (zzPeek)
                {
                    yyline--;
                }
            }
            zzAction = -1;

            zzCurrentPosL = zzCurrentPos = zzStartRead = zzMarkedPosL;

            zzState = ZZ_LEXSTATE[zzLexicalState];

zzForAction:
            {
                while (true)
                {

                    if (zzCurrentPosL < zzEndReadL)
                    {
                        zzInput = zzBufferL[zzCurrentPosL++];
                    }
                    else if (zzAtEOF)
                    {
                        zzInput = YYEOF;
                        break zzForAction;
                    }
                    else
                    {
                        // store back cached positions
                        zzCurrentPos = zzCurrentPosL;
                        zzMarkedPos = zzMarkedPosL;
                        boolean eof = zzRefill();
                        // get translated positions and possibly new buffer
                        zzCurrentPosL = zzCurrentPos;
                        zzMarkedPosL = zzMarkedPos;
                        zzBufferL = zzBuffer;
                        zzEndReadL = zzEndRead;
                        if (eof)
                        {
                            zzInput = YYEOF;
                            break zzForAction;
                        }
                        else
                        {
                            zzInput = zzBufferL[zzCurrentPosL++];
                        }
                    }
                    int zzNext = zzTransL[zzRowMapL[zzState] + zzCMapL[zzInput]];
                    if (zzNext == -1)
                    {
                        break zzForAction;
                    }
                    zzState = zzNext;

                    int zzAttributes = zzAttrL[zzState];
                    if ((zzAttributes & 1) == 1)
                    {
                        zzAction = zzState;
                        zzMarkedPosL = zzCurrentPosL;
                        if ((zzAttributes & 8) == 8)
                        {
                            break zzForAction;
                        }
                    }

                }
            }

            // store back cached position
            zzMarkedPos = zzMarkedPosL;

            switch (zzAction < 0 ? zzAction : ZZ_ACTION[zzAction])
            {
                case 2:
                {
                    System.out.print(yytext());
                }
                case 10:
                    break;
                case 5:
                {
                    stack.parenOpen(yyline + 1, yycolumn + 1);
                }
                case 11:
                    break;
                case 4:
                { // IGNORE
                }
                case 12:
                    break;
                case 9:
                {
                    stack.pushAtomForm2(yytext(), yyline + 1, yycolumn + 1);
                }
                case 13:
                    break;
                case 3:
                {
                    stack.parenClose();
                }
                case 14:
                    break;
                case 6:
                {
                    stack.pushAtomForm3(yytext(), yyline + 1, yycolumn + 1);
                }
                case 15:
                    break;
                case 7:
                {
                    stack.pushAtomForm4(yytext(), yyline + 1, yycolumn + 1);
                }
                case 16:
                    break;
                case 1:
                {
                    stack.pushAtomForm5(yytext(), yyline + 1, yycolumn + 1);
                }
                case 17:
                    break;
                case 8:
                {
                    stack.pushAtomForm1(yytext(), yyline + 1, yycolumn + 1);
                }
                case 18:
                    break;
                default:
                    if (zzInput == YYEOF && zzStartRead == zzCurrentPos)
                    {
                        zzAtEOF = true;
                        return YYEOF;
                    }
                    else
                    {
                        zzScanError(ZZ_NO_MATCH);
                    }
            }
        }
    }

    /**
     * Runs the scanner on input files.
     *
     * This is a standalone scanner, it will print any unmatched
     * text to System.out unchanged.
     *
     * @param argv the command line, contains the filenames to run
     * the scanner on.
     */
    public static void main (String argv[])
    {
        if (argv.length == 0)
        {
            System.out.println("Usage : java Lexer <inputfile>");
        }
        else
        {
            for (int i = 0; i < argv.length; i++)
            {
                Lexer scanner = null;
                try
                {
                    scanner = new Lexer(new java.io.FileReader(argv[i]));
                    while (!scanner.zzAtEOF)
                    {
                        scanner.yylex();
                    }
                }
                catch (java.io.FileNotFoundException e)
                {
                    System.out.println("File not found : \"" + argv[i] + "\"");
                }
                catch (java.io.IOException e)
                {
                    System.out.println("IO error scanning file \"" + argv[i] + "\"");
                    System.out.println(e);
                }
                catch (Exception e)
                {
                    System.out.println("Unexpected exception:");
                    e.printStackTrace();
                }
            }
        }
    }

}