marf.nlp.Parsing
Class LexicalAnalyzer

java.lang.Object
  marf.nlp.Parsing.GenericLexicalAnalyzer
      marf.nlp.Parsing.LexicalAnalyzer

public class LexicalAnalyzer
extends GenericLexicalAnalyzer

LexicalAnalyzer class encapsulates the functionality required for lexical analysis of a MARF source program.

$Id: LexicalAnalyzer.java,v 1.21 2008/01/03 03:21:57 mokhov Exp $

Since:

0.3.0.2

Version:

$Revision: 1.21 $

Author:

Serguei Mokhov

Field Summary

protected boolean	bNumberMode This flag is used for backtracking when recognizing numbers.
protected boolean	bOperatorMode This flag is used for backtracking when recognizing 'ambiguous' operators such as '<>' and '<' and friends.
protected static int	NA Just a constant used to return an error code "Not Applicable" when no error code applicable in a given situation.

Fields inherited from class marf.nlp.Parsing.GenericLexicalAnalyzer

bErrorsPresent, DEFAULT_ERROR_FILE, DEFAULT_OUTPUT_FILE, oFileReader, oLexicalErrors, oStreamTokenizer, oSymTab, oToken, oTokenList, strErrorLogFilename, strOutputFilename, strSourceFilename

Constructor Summary

LexicalAnalyzer(SymbolTable poSymTab)
Constructor with the symbol table as a reference.

Method Summary

java.util.Vector	getLexicalErrors() Returns the list of lexical errors.
static java.lang.String	getMARFSourceCodeRevision() Retrieves class' revision.
Token	getNextToken() Core method of the MARF LexicalAnalyzer.
boolean	init() Initialization routine.
boolean	serialize(int piOperation) Load/Save the textual contents of such as Token list and Error list.
protected int	validNum(java.lang.String pstrNum) Validates that an incoming string is a valid number or not.

Methods inherited from class marf.nlp.Parsing.GenericLexicalAnalyzer

createToken, getErrorLogFilename, getErrorsPresent, getOutputFilename, getSourceFilename, getSymTab, getTokenList, scan, setErrorLogFilename, setOutputFilename, setSourceFilename

Methods inherited from class java.lang.Object

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

Field Detail

NA

protected static final int NA

Just a constant used to return an error code "Not Applicable" when no error code applicable in a given situation.

See Also:

Constant Field Values

bNumberMode

protected boolean bNumberMode

This flag is used for backtracking when recognizing numbers.

bOperatorMode

protected boolean bOperatorMode

This flag is used for backtracking when recognizing 'ambiguous' operators such as '<>' and '<' and friends.

Constructor Detail

LexicalAnalyzer

public LexicalAnalyzer(SymbolTable poSymTab)

Constructor with the symbol table as a reference.

Parameters:

poSymTab - the symbol table to construct this lexical analyzer

Method Detail

init

public boolean init()

Initialization routine.

Overrides:

init in class GenericLexicalAnalyzer

Returns:

true of initialization is successful

See Also:

GenericLexicalAnalyzer.init()

serialize

public boolean serialize(int piOperation)

Load/Save the textual contents of such as Token list and Error list. 0 means load, 1 means save. Load currently is not implemented. TODO: migrate to MARF's dump/restore machinery.

Specified by:

serialize in class GenericLexicalAnalyzer

Parameters:

piOperation - 0 means load, 1 means save

Returns:

true if the serialization was successful

See Also:

GenericLexicalAnalyzer.serialize(int)

getNextToken

public Token getNextToken()
                   throws LexicalError

Core method of the MARF LexicalAnalyzer.

Specified by:

getNextToken in class GenericLexicalAnalyzer

Returns:

newly recognized lexical token

Throws:

LexicalError - in case of invalid character stream (alphabet) entries found

See Also:

GenericLexicalAnalyzer.getNextToken()

validNum

protected int validNum(java.lang.String pstrNum)

Validates that an incoming string is a valid number or not.

Parameters:

pstrNum - a string containing valid numerical chars

Returns:

int, LexicalError Error code

getLexicalErrors

public java.util.Vector getLexicalErrors()

Returns the list of lexical errors.

Overrides:

getLexicalErrors in class GenericLexicalAnalyzer

Returns:

Vector LexicalErrors

getMARFSourceCodeRevision

public static java.lang.String getMARFSourceCodeRevision()

Retrieves class' revision.

Returns:

revision string