Package com.scriptbasic.lexer

Class BasicLexicalAnalyzer

java.lang.Object

com.scriptbasic.lexer.BasicLexicalAnalyzer

All Implemented Interfaces:

LexicalAnalyzer, LineOrientedLexicalAnalyzer

Direct Known Subclasses:

ScriptBasicLexicalAnalyzer

public class BasicLexicalAnalyzer
extends Object
implements LineOrientedLexicalAnalyzer

Constructor Summary

Constructors

Constructor	Description
BasicLexicalAnalyzer(SourceReader reader)

Method Summary

Modifier and Type	Method	Description
LexicalElement	get()	Get the next lexical element from the input stream.
LexicalElement	peek()	Peek at the next lexical element and do not remove it from the input stream.
void	registerElementAnalyzer(LexicalElementAnalyzer lea)	Register a lexical element analyzer.
void	resetLine()	Resets the state of the lexical analyzer so that the internal lexeme pointer is reset to the first lexeme of the actual line and the next call to LexicalAnalyzer.get() will return again the first lexeme of the line.

Methods inherited from class java.lang.Object

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

Constructor Details

BasicLexicalAnalyzer

public BasicLexicalAnalyzer(SourceReader reader)

Method Details

registerElementAnalyzer

public void registerElementAnalyzer(LexicalElementAnalyzer lea)

Description copied from interface: LexicalAnalyzer

Register a lexical element analyzer. The lexical element analyzers are consulted in the order they are registered to match a lexeme.

Specified by:

registerElementAnalyzer in interface LexicalAnalyzer

Parameters:

lea - parameter

resetLine

public void resetLine()

Description copied from interface: LineOrientedLexicalAnalyzer

Resets the state of the lexical analyzer so that the internal lexeme pointer is reset to the first lexeme of the actual line and the next call to LexicalAnalyzer.get() will return again the first lexeme of the line.

Specified by:

resetLine in interface LineOrientedLexicalAnalyzer

get

public LexicalElement get()
                   throws AnalysisException

Description copied from interface: LexicalAnalyzer

Get the next lexical element from the input stream. If there are no more lexical elements then return null

Specified by:

get in interface LexicalAnalyzer

Returns:

return the next lexical element

Throws:

AnalysisException - in case there is an exception

peek

public LexicalElement peek()
                    throws AnalysisException

Peek at the next lexical element and do not remove it from the input stream. Consecutive calls to peek() without calling LexicalAnalyzer.get() will return the same lexical element. Calling LexicalAnalyzer.get() will return the same lexical element as the last call to peek().

Just as LexicalAnalyzer.get() this method may also return null if there are no more elements.

Specified by:

peek in interface LexicalAnalyzer

Returns:

the next lexical element

Throws:

AnalysisException - in case of exception