Package weka.core.expressionlanguage.parser

Class Scanner

java.lang.Object
weka.core.expressionlanguage.parser.Scanner
All Implemented Interfaces:
java_cup.runtime.Scanner
public class Scanner extends Object implements java_cup.runtime.Scanner
A lexical scanner for an expression language. It emerged as a superset of the weka.core.mathematicalexpression package, the weka.filers.unsupervised.instance.subsetbyexpression package and the weka.core.AttributeExpression class. Warning: This file (Scanner.java) has been auto generated by jflex.
Version:
$Revision: 1000 $
Author:
Benjamin Weber ( benweber at student dot ethz dot ch )

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    static final int
    STRING1
     
    static final int
    STRING2
     
    static final int
    YYEOF
    This character denotes the end of file.
    static final int
    YYINITIAL
     

  • Constructor Summary

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

  • Method Summary

    Modifier and Type
    Method
    Description
    java_cup.runtime.Symbol
    next_token()
    Resumes scanning until the next regular expression is matched, the end of input is encountered or an I/O-Error occurs.
    final boolean
    yyatEOF()
    Returns whether the scanner has reached the end of the reader it reads from.
    final void
    yybegin(int newState)
    Enters a new lexical state.
    final char
    yycharat(int position)
    Returns the character at the given position from the matched text.
    final void
    yyclose()
    Closes the input reader.
    final int
    yylength()
    How many characters were matched.
    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.

    Methods inherited from class java.lang.Object

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

  • Field Details

  • Constructor Details

    • Scanner

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

  • Method Details

    • yyclose

      public final void yyclose() throws IOException
      Closes the input reader.
      Throws:
      IOException - if the reader could not be closed.

    • 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.

    • yyatEOF

      public final boolean yyatEOF()
      Returns whether the scanner has reached the end of the reader it reads from.
      Returns:
      whether the scanner has reached EOF.

    • yystate

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

    • yycharat

      public final char yycharat(int position)
      Returns the character at the given position from the matched text.

      It is equivalent to yytext().charAt(pos), but faster.

      Parameters:
      position - the position of the character to fetch. A value from 0 to yylength()-1.
      Returns:
      the character at position.

    • yylength

      public final int yylength()
      How many characters were matched.
      Returns:
      the length of the matched text region.

    • yypushback

      public void yypushback(int number) throws SyntaxException
      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().
      Throws:
      SyntaxException

    • next_token

      public java_cup.runtime.Symbol next_token() throws IOException, SyntaxException
      Resumes scanning until the next regular expression is matched, the end of input is encountered or an I/O-Error occurs.
      Specified by:
      next_token in interface java_cup.runtime.Scanner
      Returns:
      the next token.
      Throws:
      IOException - if any I/O-Error occurs.
      SyntaxException