goldengine.java
Class LookAheadStream

java.lang.Object
  goldengine.java.LookAheadStream

public class LookAheadStream
extends java.lang.Object

Copy of original goldengine.java.LookAheadStream, with modified readLine() method.

Author:

Modification by "GRegory Golberg

Field Summary

private int	bufferPos
private java.io.PushbackReader	buffR
private int	kMaxBufferSize
private int	multiplier
private char[]	unreadme

Constructor Summary

LookAheadStream()

Method Summary

boolean	closeFile() closeFile This method will close the source file.
boolean	done() done This method checks the next character to see if it is the end of the file.
private void	doubleArray()
java.lang.String	nextChar() nextChar This method will read one character (int) from the stream.
boolean	nextCharNotWhitespace() nextCharNotWhitespace A quick checker method which checks to see if the next character is whitespace.
boolean	openFile(java.lang.String file) openFile This method will open the source file to read.
java.lang.String	read(int size) read This method will return a String of length size.
java.lang.String	readLine() As of today, 08/12/2005, Java engine featured on the GOLD site (http://www.devincook.com/goldparser/doc/index.htm#Engine) does NOT handle languages that use EOL as a statement separator (such as VBS).
private void	unreadChars(int size)

Methods inherited from class java.lang.Object

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

Field Detail

buffR

private java.io.PushbackReader buffR

unreadme

private char[] unreadme

kMaxBufferSize

private final int kMaxBufferSize

See Also:

Constant Field Values

multiplier

private int multiplier

bufferPos

private int bufferPos

Constructor Detail

LookAheadStream

public LookAheadStream()

Method Detail

openFile

public boolean openFile(java.lang.String file)
                 throws goldengine.java.ParserException

openFile This method will open the source file to read.

Parameters:

- name>

Returns:

True if the file was opened. It will not return false, as an exception should be thrown beforehand.

Throws:

ParserException - If the PushbackReader was not initialised.

closeFile

public boolean closeFile()
                  throws goldengine.java.ParserException

closeFile This method will close the source file.

Returns:

True if the file was closed. It will not return false, as an exception should be thrown beforehand.

Throws:

ParserException - if the file could not be closed.

doubleArray

private void doubleArray()

unreadChars

private void unreadChars(int size)

done

public boolean done()
             throws goldengine.java.ParserException

done This method checks the next character to see if it is the end of the file. If it is not, it will use the functionality of the PushbackReader to push the read character back onto the stream.

Returns:

True if it is the end of file next, false if not.

Throws:

ParserException - if the stream could not be read.

nextCharNotWhitespace

public boolean nextCharNotWhitespace()
                              throws goldengine.java.ParserException

nextCharNotWhitespace A quick checker method which checks to see if the next character is whitespace.

Returns:

True if it is not whitespace, false if it is.

Throws:

ParserException - if the stream could not be read.

nextChar

public java.lang.String nextChar()
                          throws goldengine.java.ParserException

nextChar This method will read one character (int) from the stream.

Returns:

It will return the character as a String, unless it is the end of string, where it will return the character represented by the int "2".

Throws:

ParserException - if the stream could not be read.

read

public java.lang.String read(int size)
                      throws goldengine.java.ParserException

read This method will return a String of length size. The String is contained in the buffer of read characters.

Parameters:

size - The number of characters to read from the buffer.

Returns:

The String created from the buffer.

Throws:

ParserException - if the stream could not be read.

readLine

public java.lang.String readLine()
                          throws goldengine.java.ParserException

As of today, 08/12/2005, Java engine featured on the GOLD site (http://www.devincook.com/goldparser/doc/index.htm#Engine) does NOT handle languages that use EOL as a statement separator (such as VBS). In particular, lines of code that end with a line comment, such as:

 
  IF x>0 THEN ' X is positive 
  
 

The workaround is to this method with the following:

 public String readLine() throws ParserException {
        int charSpace = 0;
        boolean endReached = false;
        String text = "", ch;
        while (!endReached & !done()) {
                ch = nextChar();
                if (ch.charAt(0) == '\r' || ch.charAt(0) == '\n') {
                        break;
                }
                charSpace++;
                text += ch;
        }
        unreadChars(charSpace);
        return text;
 }
 

Notice that this does not really readLine, it reads UP TO EOL. However, the languages for which EOL is whitespace won't care, and the languages which care about EOL will just get it and handle it appropriately otherwise. This second behavior is exactly what I needed. Furthermore, this method is only called in one place -- precisely to handle line comments. This bug fix may already have made it into that package by the time you read this. But if not, here you go.

Throws:

goldengine.java.ParserException

See Also:

http://www.devincook.com/GOLDParser/engine/java-hawkins/doc/LookAheadStream.html#readLine()