Class LexicalAnalyzer

java.lang.Object
LexicalAnalyzer
public class LexicalAnalyzer extends Object
Scanner class, generated by JFlex. Function yylex() is the important one as it reads the file and returns the next matched token.

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    static final int
    LONGCOMMENTS
     
    private int
    yychar
    the number of characters up to the start of the matched text
    private int
    yycolumn
    the number of characters from the last newline up to the start of the matched text
    static final int
    YYEOF
    This character denotes the end of file
    static final int
    YYINITIAL
    lexical states
    private int
    yyline
    number of newlines encountered up to the start of the matched text
    private static final int[]
    ZZ_ACTION
    Translates DFA states to action switch labels.
    private static final String
    ZZ_ACTION_PACKED_0
     
    private static final int[]
    ZZ_ATTRIBUTE
    ZZ_ATTRIBUTE[aState] contains the attributes of state aState
    private static final String
    ZZ_ATTRIBUTE_PACKED_0
     
    private static final int
    ZZ_BUFFERSIZE
    initial size of the lookahead buffer
    private static final char[]
    ZZ_CMAP
    Translates characters to character classes
    private static final String
    ZZ_CMAP_PACKED
    Translates characters to character classes
    private static final String[]
    ZZ_ERROR_MSG
     
    private static final int[]
    ZZ_LEXSTATE
    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_NO_MATCH
     
    private static final int
    ZZ_PUSHBACK_2BIG
     
    private static final int[]
    ZZ_ROWMAP
    Translates a state to a row index in the transition table
    private static final String
    ZZ_ROWMAP_PACKED_0
     
    private static final int[]
    ZZ_TRANS
    The transition table of the DFA
    private static final String
    ZZ_TRANS_PACKED_0
     
    private static final int
    ZZ_UNKNOWN_ERROR
     
    private boolean
    zzAtBOL
    zzAtBOL == true iff the scanner is currently at the beginning of a line
    private boolean
    zzAtEOF
    zzAtEOF == true iff the scanner is at the EOF
    private char[]
    zzBuffer
    this buffer contains the current text to be matched and is the source of the yytext() string
    private int
    zzCurrentPos
    the current text position in the buffer
    private int
    zzEndRead
    endRead marks the last character in the buffer, that has been read from input
    private boolean
    zzEOFDone
    denotes if the user-EOF-code has already been executed
    private int
    zzFinalHighSurrogate
    The number of occupied positions in zzBuffer beyond zzEndRead.
    private int
    zzLexicalState
    the current lexical state
    private int
    zzMarkedPos
    the textposition at the last accepting state
    private Reader
    zzReader
    the input device
    private int
    zzStartRead
    startRead marks the beginning of the yytext() string in the buffer
    private int
    zzState
    the current state of the DFA

  • Constructor Summary

    Constructors
    Constructor
    Description
    LexicalAnalyzer(Reader in)
    Creates a new scanner

  • Method Summary

    Modifier and Type
    Method
    Description
    private Symbol
    symbol(LexicalUnit type)
    Builds a Symbol with the given lexical unit, using the current position in the source (line and column) and the matched text (yytext()) as its value.
    private Symbol
    symbol(LexicalUnit type, Object value)
    Builds a Symbol with the given lexical unit and a specific value, using the current position in the source (line and column).
    final void
    yybegin(int newState)
    Enters a new lexical state
    final char
    yycharat(int pos)
    Returns the character at position pos from the matched text.
    final void
    yyclose()
    Closes the input stream.
    final int
    yylength()
    Returns the length of the matched text region.
    Symbol
    yylex()
    Resumes scanning until the next regular expression is matched, the end of input is encountered or an I/O-Error occurs.
    void
    yypushback(int number)
    Pushes the specified amount of characters back into the input stream.
    final void
    yyreset(Reader reader)
    Resets the scanner to read from a new input stream.
    final int
    yystate()
    Returns the current lexical state.
    final String
    yytext()
    Returns the text matched by the current regular expression.
    private boolean
    zzRefill()
    Refills the input buffer.
    private void
    zzScanError(int errorCode)
    Reports an error that occured while scanning.
    private static int[]
    zzUnpackAction()
     
    private static int
    zzUnpackAction(String packed, int offset, int[] result)
     
    private static int[]
    zzUnpackAttribute()
     
    private static int
    zzUnpackAttribute(String packed, int offset, int[] result)
     
    private static char[]
    zzUnpackCMap(String packed)
    Unpacks the compressed character translation table.
    private static int[]
    zzUnpackRowMap()
     
    private static int
    zzUnpackRowMap(String packed, int offset, int[] result)
     
    private static int[]
    zzUnpackTrans()
     
    private static int
    zzUnpackTrans(String packed, int offset, int[] result)
     

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Field Details

    • YYEOF

      public static final int YYEOF
      This character denotes the end of file
      See Also:

    • ZZ_BUFFERSIZE

      private static final int ZZ_BUFFERSIZE
      initial size of the lookahead buffer
      See Also:

    • YYINITIAL

      public static final int YYINITIAL
      lexical states
      See Also:

    • LONGCOMMENTS

      public static final int LONGCOMMENTS
      See Also:

    • ZZ_LEXSTATE

      private static final int[] ZZ_LEXSTATE
      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

    • ZZ_CMAP_PACKED

      private static final String ZZ_CMAP_PACKED
      Translates characters to character classes
      See Also:

    • ZZ_CMAP

      private static final char[] ZZ_CMAP
      Translates characters to character classes

    • ZZ_ACTION

      private static final int[] ZZ_ACTION
      Translates DFA states to action switch labels.

    • ZZ_ACTION_PACKED_0

      private static final String ZZ_ACTION_PACKED_0
      See Also:

    • ZZ_ROWMAP

      private static final int[] ZZ_ROWMAP
      Translates a state to a row index in the transition table

    • ZZ_ROWMAP_PACKED_0

      private static final String ZZ_ROWMAP_PACKED_0
      See Also:

    • ZZ_TRANS

      private static final int[] ZZ_TRANS
      The transition table of the DFA

    • ZZ_TRANS_PACKED_0

      private static final String ZZ_TRANS_PACKED_0
      See Also:

    • ZZ_UNKNOWN_ERROR

      private static final int ZZ_UNKNOWN_ERROR
      See Also:

    • ZZ_NO_MATCH

      private static final int ZZ_NO_MATCH
      See Also:

    • ZZ_PUSHBACK_2BIG

      private static final int ZZ_PUSHBACK_2BIG
      See Also:

    • ZZ_ERROR_MSG

      private static final String[] ZZ_ERROR_MSG

    • ZZ_ATTRIBUTE

      private static final int[] ZZ_ATTRIBUTE
      ZZ_ATTRIBUTE[aState] contains the attributes of state aState

    • ZZ_ATTRIBUTE_PACKED_0

      private static final String ZZ_ATTRIBUTE_PACKED_0
      See Also:

    • zzReader

      private Reader zzReader
      the input device

    • zzState

      private int zzState
      the current state of the DFA

    • zzLexicalState

      private int zzLexicalState
      the current lexical state

    • zzBuffer

      private char[] zzBuffer
      this buffer contains the current text to be matched and is the source of the yytext() string

    • zzMarkedPos

      private int zzMarkedPos
      the textposition at the last accepting state

    • zzCurrentPos

      private int zzCurrentPos
      the current text position in the buffer

    • zzStartRead

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

    • zzEndRead

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

    • yyline

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

    • yychar

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

    • yycolumn

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

    • zzAtBOL

      private boolean zzAtBOL
      zzAtBOL == true iff the scanner is currently at the beginning of a line

    • zzAtEOF

      private boolean zzAtEOF
      zzAtEOF == true iff the scanner is at the EOF

    • zzEOFDone

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

    • zzFinalHighSurrogate

      private int zzFinalHighSurrogate
      The number of occupied positions in zzBuffer beyond zzEndRead. When a lead/high surrogate has been read from the input stream into the final zzBuffer position, this will have a value of 1; otherwise, it will have a value of 0.

  • Constructor Details

    • LexicalAnalyzer

      public LexicalAnalyzer(Reader in)
      Creates a new scanner
      Parameters:
      in - the java.io.Reader to read input from.

  • Method Details

    • zzUnpackAction

      private static int[] zzUnpackAction()

    • zzUnpackAction

      private static int zzUnpackAction(String packed, int offset, int[] result)

    • zzUnpackRowMap

      private static int[] zzUnpackRowMap()

    • zzUnpackRowMap

      private static int zzUnpackRowMap(String packed, int offset, int[] result)

    • zzUnpackTrans

      private static int[] zzUnpackTrans()

    • zzUnpackTrans

      private static int zzUnpackTrans(String packed, int offset, int[] result)

    • zzUnpackAttribute

      private static int[] zzUnpackAttribute()

    • zzUnpackAttribute

      private static int zzUnpackAttribute(String packed, int offset, int[] result)

    • symbol

      private Symbol symbol(LexicalUnit type)
      Builds a Symbol with the given lexical unit, using the current position in the source (line and column) and the matched text (yytext()) as its value.
      Parameters:
      type - the lexical unit (token type) to associate with this symbol
      Returns:
      a new Symbol representing the matched token

    • symbol

      private Symbol symbol(LexicalUnit type, Object value)
      Builds a Symbol with the given lexical unit and a specific value, using the current position in the source (line and column). This is used for tokens that carry semantic values (e.g., numbers, identifiers).
      Parameters:
      type - the lexical unit (token type)
      value - the semantic value of the token (e.g., Integer, String)
      Returns:
      a new Symbol representing the matched token with its value

    • zzUnpackCMap

      private static char[] zzUnpackCMap(String packed)
      Unpacks the compressed character translation table.
      Parameters:
      packed - the packed character translation table
      Returns:
      the unpacked character translation table

    • zzRefill

      private boolean zzRefill() throws IOException
      Refills the input buffer.
      Returns:
      false, iff there was new input.
      Throws:
      IOException - if any I/O-Error occurs

    • yyclose

      public final void yyclose() throws IOException
      Closes the input stream.
      Throws:
      IOException

    • yyreset

      public final void yyreset(Reader reader)
      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 cannot be reused (internal buffer is discarded and lost). Lexical state is set to ZZ_INITIAL. Internal scan buffer is resized down to its initial length, if it has grown.
      Parameters:
      reader - the new input stream

    • yystate

      public final int yystate()
      Returns the current lexical state.

    • yybegin

      public final void yybegin(int newState)
      Enters a new lexical state
      Parameters:
      newState - the new lexical state

    • yytext

      public final String yytext()
      Returns the text matched by the current regular expression.

    • yycharat

      public final char yycharat(int pos)
      Returns the character at position pos from the matched text. It is equivalent to yytext().charAt(pos), but faster
      Parameters:
      pos - the position of the character to fetch. A value from 0 to yylength()-1.
      Returns:
      the character at position pos

    • yylength

      public final int yylength()
      Returns the length of the matched text region.

    • zzScanError

      private void zzScanError(int errorCode)
      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.
      Parameters:
      errorCode - the code of the errormessage to display

    • yypushback

      public void yypushback(int number)
      Pushes the specified amount of characters back into the input stream. They will be read again by then next call of the scanning method
      Parameters:
      number - the number of characters to be read again. This number must not be greater than yylength()!

    • yylex

      public Symbol yylex() throws IOException
      Resumes scanning until the next regular expression is matched, the end of input is encountered or an I/O-Error occurs.
      Returns:
      the next token
      Throws:
      IOException - if any I/O-Error occurs