edu.isi.pegasus.planner.parser
Class TransformationCatalogTextScanner

java.lang.Object
  edu.isi.pegasus.planner.parser.TransformationCatalogTextScanner

public class TransformationCatalogTextScanner
extends Object

Implements the scanner for reserved words and other tokens that are generated from the input stream for the Transformation Catalog.

Author:

Jens Vöckler, Karan Vahi

Field Summary

private LineNumberReader	mInputReader Stores the stream from which we are currently scanning.
private int	mLookAhead Captures the look-ahead character.
private Token	mPreviousToken Captures the previous token.

Constructor Summary

TransformationCatalogTextScanner(Reader reader)
Starts to scan the given stream.

Method Summary

int	getLineNumber() Obtains the current line number in the input stream from the outside.
boolean	hasMoreTokens() Checks for the availability of more input.
Token	nextToken() Obtains the next token from the input stream.
private void	skipWhitespace() Skips any white space and comments in the input.

Methods inherited from class java.lang.Object

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

Field Detail

mInputReader

private LineNumberReader mInputReader

Stores the stream from which we are currently scanning.

mLookAhead

private int mLookAhead

Captures the look-ahead character.

mPreviousToken

private Token mPreviousToken

Captures the previous token. Required to parse transformation value correctly.

Constructor Detail

TransformationCatalogTextScanner

public TransformationCatalogTextScanner(Reader reader)
                                 throws IOException

Starts to scan the given stream.

Parameters:

reader - the reader stream from which we are reading the site catalog.

Throws:

IOException

Method Detail

getLineNumber

public int getLineNumber()

Obtains the current line number in the input stream from the outside.

Returns:

the current line number.

skipWhitespace

private void skipWhitespace()
                     throws IOException

Skips any white space and comments in the input. This method stops either at the end of file, or at any non-whitespace input character.

Throws:

IOException

hasMoreTokens

public boolean hasMoreTokens()
                      throws IOException

Checks for the availability of more input.

Returns:

true, if there is more to read, false for EOF.

Throws:

IOException

nextToken

public Token nextToken()
                throws IOException,
                       ScannerException

Obtains the next token from the input stream.

Returns:

an instance conforming to the token interface, or null for eof.

Throws:

IOException - if something went wrong while reading

Exception - if a lexical error was encountered.

ScannerException