jeops.compiler
Class Main

java.lang.Object
  |
  +--jeops.compiler.Main

public class Main

extends java.lang.Object

implements TokenConstants

Main class in the Jeops phase of converting rule files into Java classes.

When invoked, the method convert() will create a java file in the same directory as the rule file (with the extension changed from .rules to .java). In this way, rule files can be grouped into packages in the same way as java classes.

Version:

0.02 14.01.2000 Grouping of the conditions according to the appearance of the declaration.

Author:

Carlos Figueira Filho (csff@cin.ufpe.br)

Field Summary

private java.util.Vector	allDeclForLocalDecl The index of all declared identifiers used by some rule local declaration.
private java.util.Vector	convertedRuleDeclarations The converted declarations of the current rule.
private java.util.Vector	convertedRuleLocalDeclarations The converted local declarations of the current rule.
private java.util.Vector	declaredClassNames The classes of the identifiers generated in the new java file.
private ImportList	importList The import list of this rule base.
private java.lang.String	javaFileName The name of the generated java file.
private java.util.Vector	lastDeclForLocalDecl The index of the last declared identifier used by some rule local declaration.
private java.util.Vector	localDeclClasses Vector (of vectors) of the classes of the local declarations.
private java.util.Vector	numberOfConditions The number of conditions in each rule.
private java.util.Vector	numberOfDeclarations The number of declarations in each rule.
private java.util.Vector	numberOfLocalDeclarations The number of local declarations in each rule.
private java.lang.String	ruleBaseName The name of this rule base.
private java.util.Vector	ruleDeclarations The declarations of the current rule.
private java.lang.String	ruleFileName The name of the rules file.
private java.util.Vector	ruleLocalDeclarations The local declarations of the current rule.
private java.lang.String	ruleName The name of the rule being converted.
private java.util.Vector	ruleNames The names of the rules.
private Scanner	scanner The scanner used to read from the input file.
private boolean	thereIsRuleBase Flag that indicates whether a rule base is declared in the file.
private Token	token The current token.
private java.util.Vector	variableIdents The list of the identifiers of the instance variables of the generated java file.
private java.util.Vector	variables The list of declaration of instance variables of the generated java file.
private java.io.PrintWriter	writer The writer used to create the java file.

Fields inherited from interface jeops.compiler.parser.TokenConstants

ACTIONS, ASTERISK, CLOSE_CURLY_BRACKET, COMMA, COMMENT, CONDITIONS, DECLARATIONS, DOT, EOF, EQUALS, ERROR, EXTENDS, IDENT, IMPLEMENTS, IMPORT, LOCALDECL, NONE_ABOVE, OPEN_CURLY_BRACKET, PACKAGE, PUBLIC, RULE, RULE_BASE, SEMICOLON, STRING, WHITE_SPACE

Constructor Summary

Main(java.lang.String ruleFileName)
Class constructor.

Method Summary

private void	checkToken(Token token, int[] tokenTypes, java.lang.String message) Checks whether a token is one of several given types, throwing an exception if it's not.
private void	checkToken(Token token, int tokenType, java.lang.String message) Checks whether a token is of a given type, throwing an exception if it's not.
private boolean	compileSourceFile(java.lang.String className) Attempts to find a source file and compile it into a .class file.
void	convert() Creates a java source file that behaves as defined in the rules file.
private void	convertRule(java.io.PrintWriter writer) Converts a rule into a set of java methods.
private void	convertRuleActions(java.io.PrintWriter writer) Processes the actions part of a rule.
private void	convertRuleConditions(java.io.PrintWriter writer) Processes the conditions part of a rule.
private void	convertRuleDeclarations(java.io.PrintWriter writer) Processes the declaration part of a rule.
private void	convertRuleLocalDeclarations(java.io.PrintWriter writer) Processes the local declarations part of a rule.
static void	main(java.lang.String[] args) Test method for this class.
private void	processEndOfRuleBase(java.io.PrintWriter writer) Processes the end of the rule base, adding control information.
private void	processImport(java.io.PrintWriter writer) Processes an import statement of a rule base.
private void	processPackage(java.io.PrintWriter writer) Processes the package statement of a rule base.
private Token	readNextToken() Reads the next token from the scanner, throwing an exception in case of an error.
private void	skipWhiteSpace(java.io.PrintWriter writer, boolean outputComments) Auxiliar method used to advance through white space and comments.

Methods inherited from class java.lang.Object

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

Field Detail

writer

private java.io.PrintWriter writer

The writer used to create the java file.

ruleFileName

private java.lang.String ruleFileName

The name of the rules file.

javaFileName

private java.lang.String javaFileName

The name of the generated java file.

ruleBaseName

private java.lang.String ruleBaseName

The name of this rule base.

scanner

private Scanner scanner

The scanner used to read from the input file.

token

private Token token

The current token.

variables

private java.util.Vector variables

The list of declaration of instance variables of the generated java file.

variableIdents

private java.util.Vector variableIdents

The list of the identifiers of the instance variables of the generated java file.

declaredClassNames

private java.util.Vector declaredClassNames

The classes of the identifiers generated in the new java file.

ruleName

private java.lang.String ruleName

The name of the rule being converted.

numberOfDeclarations

private java.util.Vector numberOfDeclarations

The number of declarations in each rule.

numberOfLocalDeclarations

private java.util.Vector numberOfLocalDeclarations

The number of local declarations in each rule.

numberOfConditions

private java.util.Vector numberOfConditions

The number of conditions in each rule.

ruleNames

private java.util.Vector ruleNames

The names of the rules.

importList

private ImportList importList

The import list of this rule base.

ruleDeclarations

private java.util.Vector ruleDeclarations

The declarations of the current rule.

convertedRuleDeclarations

private java.util.Vector convertedRuleDeclarations

The converted declarations of the current rule.

ruleLocalDeclarations

private java.util.Vector ruleLocalDeclarations

The local declarations of the current rule.

convertedRuleLocalDeclarations

private java.util.Vector convertedRuleLocalDeclarations

The converted local declarations of the current rule.

lastDeclForLocalDecl

private java.util.Vector lastDeclForLocalDecl

The index of the last declared identifier used by some rule local declaration.

allDeclForLocalDecl

private java.util.Vector allDeclForLocalDecl

The index of all declared identifiers used by some rule local declaration. It's a vector of Integer Vectors.

thereIsRuleBase

private boolean thereIsRuleBase

Flag that indicates whether a rule base is declared in the file.

localDeclClasses

private java.util.Vector localDeclClasses

Vector (of vectors) of the classes of the local declarations.

Constructor Detail

Main

public Main(java.lang.String ruleFileName)
     throws java.io.IOException

Class constructor.

Parameters:

ruleFileName - the name of the rules file.

Throws:

java.io.IOException - if some IO error occurs.

Method Detail

checkToken

private void checkToken(Token token,
                        int[] tokenTypes,
                        java.lang.String message)
                 throws JeopsException

Checks whether a token is one of several given types, throwing an exception if it's not.

Parameters:

token - the token to be checked.

types - the desired token types.

message - the message in the exception.

Throws:

JeopsException - if the token is of an unexpected type.

checkToken

private void checkToken(Token token,
                        int tokenType,
                        java.lang.String message)
                 throws JeopsException

Checks whether a token is of a given type, throwing an exception if it's not.

Parameters:

token - the token to be checked.

type - the desired token type.

message - the message in the exception.

Throws:

JeopsException - if the token is of an unexpected type.

compileSourceFile

private boolean compileSourceFile(java.lang.String className)
                           throws JeopsException

Attempts to find a source file and compile it into a .class file.

Parameters:

className - the name of the class to be compiled.

Returns:

true if the compilation could be performed; false otherwise.

Throws:

JeopsException - if some error occurred during the compilation.

convert

public void convert()
             throws java.io.IOException,
                    JeopsException

Creates a java source file that behaves as defined in the rules file.

Throws:

java.io.IOException - if some IO error occurs.

JeopsException - if some error occurs while converting the rule.

convertRule

private void convertRule(java.io.PrintWriter writer)
                  throws java.io.IOException,
                         JeopsException

Converts a rule into a set of java methods.

Parameters:

writer - the print writer used to write to the generated file.

Throws:

java.io.IOException - if some IO error occurs.

JeopsException - if some error occurs while converting the rule.

convertRuleActions

private void convertRuleActions(java.io.PrintWriter writer)
                         throws java.io.IOException,
                                JeopsException

Processes the actions part of a rule. This method creates one void method for the whole body of actions of the rule. The method will have the same name of the rule.

In order to be correctly invoked, the current token type must be ACTIONS. After successful completion, the token type is CLOSE_CURLY_BRACKET, indicating the end of the rule.

Parameters:

writer - the print writer used to write to the generated file.

Throws:

java.io.IOException - if some IO error occurs.

JeopsException - if some error occurs while converting the rule.

convertRuleConditions

private void convertRuleConditions(java.io.PrintWriter writer)
                            throws java.io.IOException,
                                   JeopsException

Processes the conditions part of a rule. This method creates one method (returning a boolean value) for every condition of the rule. Each method will be named as the name of the rule followed by "_cond_", where n is the index of the condition. Additionally, another method will be created, named as the name of the rule followed only by "_cond", that will receive an integer used to check the correct condition.

In order to be correctly invoked, the current token type must be CONDITIONS. After successful completion, the token type is ACTIONS.

Parameters:

writer - the print writer used to write to the generated file.

Throws:

java.io.IOException - if some IO error occurs.

JeopsException - if some error occurs while converting the rule.

convertRuleDeclarations

private void convertRuleDeclarations(java.io.PrintWriter writer)
                              throws java.io.IOException,
                                     JeopsException

Processes the declaration part of a rule. This method fills the ruleDeclaration and convertedRuleDeclaration fields with the declared variables and their counterpart in the generated java file. It will also fill the condGrouping field.

This method also deals with the optional section of local declarations of the rule, so that it guarantees that after this method is successfully invoked, the token type is CONDITIONS

. In order to be correctly invoked, the current token type must be DECLARATIONS. After successful completion, the token type is CONDITIONS.

Parameters:

writer - the print writer used to write to the generated file.

Throws:

java.io.IOException - if some IO error occurs.

JeopsException - if some error occurs while converting the rule.

convertRuleLocalDeclarations

private void convertRuleLocalDeclarations(java.io.PrintWriter writer)
                                   throws java.io.IOException,
                                          JeopsException

Processes the local declarations part of a rule. This method continues filling the ruleLocalDeclaration and convertedRuleLocalDeclaration fields with the locally declared variables and their counterpart in the generated java file.

In order to be correctly invoked, the current token type must be LOCALDECL. After successful completion, the token type is CONDITIONS.

Parameters:

writer - the print writer used to write to the generated file.

Throws:

java.io.IOException - if some IO error occurs.

JeopsException - if some error occurs while converting the rule.

main

public static void main(java.lang.String[] args)

Test method for this class.

Parameters:

args - command-line arguments. None is needed, but one can pass the rule file name for the converting.

processEndOfRuleBase

private void processEndOfRuleBase(java.io.PrintWriter writer)
                           throws java.io.IOException

Processes the end of the rule base, adding control information.

Parameters:

writer - the print writer used to write to the generated file.

Throws:

java.io.IOException - if some IO error occurs.

processImport

private void processImport(java.io.PrintWriter writer)
                    throws java.io.IOException,
                           JeopsException

Processes an import statement of a rule base.

Parameters:

writer - the print writer used to write to the generated file.

Throws:

java.io.IOException - if some IO error occurs.

JeopsException - if some error occurs while converting the rule.

processPackage

private void processPackage(java.io.PrintWriter writer)
                     throws java.io.IOException,
                            JeopsException

Processes the package statement of a rule base.

Parameters:

writer - the print writer used to write to the generated file.

Throws:

java.io.IOException - if some IO error occurs.

JeopsException - if some error occurs while converting the rule.

readNextToken

private Token readNextToken()
                     throws java.io.IOException,
                            JeopsException

Reads the next token from the scanner, throwing an exception in case of an error.

Returns:

the token read from the scanner.

Throws:

java.io.IOException - if some IO error occurs.

JeopsException - is the token read is an error.

skipWhiteSpace

private void skipWhiteSpace(java.io.PrintWriter writer,
                            boolean outputComments)
                     throws java.io.IOException

Auxiliar method used to advance through white space and comments. The caller must indicate whether the comments should be written to the output file. This method throws an error if EOF is found.

Parameters:

writer - the print writer used to write to the generated file.

outputComments - if the white space and comments should be written to the output file

Throws:

java.io.IOException - if some IO error occurs.