Package edu.odu.cs.cs350

Class LexerAnalyzer

  • public class LexerAnalyzer
extends java.lang.Object

    • Field Summary

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

    • Constructor Summary

      Constructors 
      Constructor Description
      LexerAnalyzer​(java.io.Reader in)
      Creates a new scanner

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      boolean yyatEOF()
      Returns whether the scanner has reached the end of the reader it reads from.
      void yybegin​(int newState)
      Enters a new lexical state.
      char yycharat​(int position)
      Returns the character at the given position from the matched text.
      void yyclose()
      Closes the input reader.
      int yylength()
      How many characters were matched.
      Token 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.
      void yyreset​(java.io.Reader reader)
      Resets the scanner to read from a new input stream.
      int yystate()
      Returns the current lexical state.
      java.lang.String yytext()
      Returns the text matched by the current regular expression.

      • Methods inherited from class java.lang.Object

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

    • Constructor Detail

      • LexerAnalyzer

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

    • Method Detail

      • yyclose

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

      • yyreset

        public final void yyreset​(java.io.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 java.lang.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)
        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 Token yylex()
            throws java.io.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:
        java.io.IOException - if any I/O-Error occurs.