CS 536 Fall 2007, Project 5

Class Scanner

Object
  extended by Scanner

 class Scanner
extends Object

This class is a scanner generated by JFlex 1.4.1 on 11/19/07 6:56 AM from the specification file ada536.jflex


Field Summary
static int YYEOF
          This character denotes the end of file
static int YYINITIAL
          lexical states
 
Constructor Summary
Scanner(InputStream in)
          Creates a new scanner.
Scanner(Reader in)
          Creates a new scanner There is also a java.io.InputStream version of this constructor.
 
Method Summary
 int currentColumn()
          Returns the column number (starting with 1) of the start of the most recently returned token.
 int currentLine()
          Returns the source line number (starting with 1) of the most recently returned token.
 Token next()
          Resumes scanning until the next regular expression is matched, the end of input is encountered or an I/O-Error occurs.
 void yybegin(int newState)
          Enters a new lexical state
 char yycharat(int pos)
          Returns the character at position pos from the matched text.
 void yyclose()
          Closes the input stream.
 int yylength()
          Returns the length of the matched text region.
 void yypushback(int number)
          Pushes the specified amount of characters back into the input stream.
 void yyreset(Reader reader)
          Resets the scanner to read from a new input stream.
 int yystate()
          Returns the current lexical state.
 String yytext()
          Returns the text matched by the current regular expression.
 
Methods inherited from class Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

YYEOF

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

See Also:
Constant Field Values

YYINITIAL

public static final int YYINITIAL
lexical states

See Also:
Constant Field Values
Constructor Detail

Scanner

Scanner(Reader in)
Creates a new scanner There is also a java.io.InputStream version of this constructor.

Parameters:
in - the java.io.Reader to read input from.

Scanner

Scanner(InputStream in)
Creates a new scanner. There is also java.io.Reader version of this constructor.

Parameters:
in - the java.io.Inputstream to read input from.
Method Detail

currentLine

public int currentLine()
Returns the source line number (starting with 1) of the most recently returned token.

Returns:
the line number

currentColumn

public int currentColumn()
Returns the column number (starting with 1) of the start of the most recently returned token.

Returns:
the column number

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.

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.


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()!

next

public Token next()
           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

CS 536 Fall 2007, Project 5