leola.frontend

Class LeolaParser

java.lang.Object

leola.frontend.Parser

leola.frontend.LeolaParser

Direct Known Subclasses:

StmtParser

public class LeolaParser
extends Parser

A Parser for the Leola programming language.

Author:

Tony

Field Summary

Fields inherited from class leola.frontend.Parser

scanner

Constructor Summary

Constructors

Constructor and Description
LeolaParser(LeolaParser parser) Copy constructor
LeolaParser(Scanner scanner, ExceptionHandler exceptionHandler)

Method Summary

Modifier and Type	Method and Description
void	expectToken(Token currentToken, LeolaTokenType expectedType, LeolaErrorCode errorCode) Expect that the current token is of the supplied LeolaTokenType.
Token	expectTokenNext(Token currentToken, LeolaTokenType expectedType, LeolaErrorCode errorCode) Expect that the current token is of the supplied LeolaTokenType.
int	getErrorCount() Return the number of syntax errors found by the parser.
ASTNode	parse() Parse a source program and generate the intermediate code and the symbol table.
protected void	setLineNumber(ASTNode node, Token token) Set the current line number as a statement node attribute.
void	throwParseError(Token token, LeolaErrorCode errorCode) Issues a parsing exception.

Methods inherited from class leola.frontend.Parser

currentToken, getEventDispatcher, getExceptionHandler, getScanner, getSource, nextToken, previousToken

Methods inherited from class java.lang.Object

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

Constructor Detail

LeolaParser

public LeolaParser(Scanner scanner,
                   ExceptionHandler exceptionHandler)

Parameters:

scanner -

LeolaParser

public LeolaParser(LeolaParser parser)

Copy constructor

Parameters:

parser -

Method Detail

getErrorCount

public int getErrorCount()

Description copied from class: Parser

Return the number of syntax errors found by the parser. To be implemented by a language-specific parser subclass.

Specified by:

getErrorCount in class Parser

Returns:

the error count.

setLineNumber

protected void setLineNumber(ASTNode node,
                             Token token)

Set the current line number as a statement node attribute.

Parameters:

node - ICodeNode

token - Token

parse

public ASTNode parse()
              throws Exception

Description copied from class: Parser

Parse a source program and generate the intermediate code and the symbol table. To be implemented by a language-specific parser subclass.

Specified by:

parse in class Parser

Throws:

Exception - if an error occurred.

throwParseError

public void throwParseError(Token token,
                            LeolaErrorCode errorCode)

Issues a parsing exception.

Parameters:

token -

errorCode -

expectToken

public void expectToken(Token currentToken,
                        LeolaTokenType expectedType,
                        LeolaErrorCode errorCode)

Expect that the current token is of the supplied LeolaTokenType. If the expected token is not a match, a parser error is thrown (parserthrowParseError(Token, LeolaErrorCode).

Parameters:

currentToken - the current Token, that will be validated

expectedType - the expected LeolaTokenType, which should match the currentToken

errorCode - the LeolaErrorCode that will be raised if the current token does not match the expected type

expectTokenNext

public Token expectTokenNext(Token currentToken,
                             LeolaTokenType expectedType,
                             LeolaErrorCode errorCode)
                      throws IOException

Expect that the current token is of the supplied LeolaTokenType. If the expected token is not a match, a parser error is thrown (parserthrowParseError(Token, LeolaErrorCode). If there is a match, Parser.nextToken() is called.

Parameters:

currentToken - the current Token, that will be validated

expectedType - the expected LeolaTokenType, which should match the currentToken

errorCode - the LeolaErrorCode that will be raised if the current token does not match the expected type

Returns:

calls Parser.nextToken() and returns the Token

Throws:

IOException