/*
* JavaParserFile.java
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public License
* as published by the Free Software Foundation; either version 3
* of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free
* Software Foundation, Inc., 59 Temple Place, Suite 330, Boston,
* MA 02111-1307, USA.
*
* Copyright (c) 2003-2009 Per Cederberg. All rights reserved.
*/
package net.percederberg.grammatica.output;
import java.io.IOException;
import java.util.HashMap;
import net.percederberg.grammatica.code.java.JavaClass;
import net.percederberg.grammatica.code.java.JavaComment;
import net.percederberg.grammatica.code.java.JavaConstructor;
import net.percederberg.grammatica.code.java.JavaFile;
import net.percederberg.grammatica.code.java.JavaImport;
import net.percederberg.grammatica.code.java.JavaMethod;
import net.percederberg.grammatica.code.java.JavaVariable;
import net.percederberg.grammatica.parser.ProductionPattern;
import net.percederberg.grammatica.parser.ProductionPatternAlternative;
import net.percederberg.grammatica.parser.ProductionPatternElement;
/**
* The Java parser file generator. This class encapsulates all the
* Java code necessary for creating a parser.
*
* @author Per Cederberg, <per at percederberg dot net>
* @version 1.5
*/
class JavaParserFile {
/**
* The class comment.
*/
private static final String TYPE_COMMENT =
"A token stream parser.";
/**
* The production constant comment.
*/
private static final String PRODUCTION_COMMENT =
"A generated production node identity constant.";
/**
* The first constructor comment.
*/
private static final String CONSTRUCTOR1_COMMENT =
"Creates a new parser with a default analyzer.\n\n" +
"@param in the input stream to read from\n\n" +
"@throws ParserCreationException if the parser couldn't be\n" +
" initialized correctly";
/**
* The second constructor comment.
*/
private static final String CONSTRUCTOR2_COMMENT =
"Creates a new parser.\n\n" +
"@param in the input stream to read from\n" +
"@param analyzer the analyzer to use while parsing\n\n" +
"@throws ParserCreationException if the parser couldn't be\n" +
" initialized correctly";
/**
* The tokenizer factory method comment.
*/
private static final String FACTORY_COMMENT =
"Creates a new tokenizer for this parser. Can be overridden by a\n" +
"subclass to provide a custom implementation.\n\n" +
"@param in the input stream to read from\n\n" +
"@return the tokenizer created\n\n" +
"@throws ParserCreationException if the tokenizer couldn't be\n" +
" initialized correctly";
/**
* The init method comment.
*/
private static final String INIT_METHOD_COMMENT =
"Initializes the parser by creating all the production patterns.\n\n" +
"@throws ParserCreationException if the parser couldn't be\n" +
" initialized correctly";
/**
* The Java parser generator.
*/
private JavaParserGenerator gen;
/**
* The Java file to write.
*/
private JavaFile file;
/**
* The Java class to write.
*/
private JavaClass cls;
/**
* The Java class initializer method.
*/
private JavaMethod initMethod;
/**
* A map with the production constants in this class. This map
* is indexed with the pattern id and contains the production
* constant name.
*/
private HashMap constantNames = new HashMap();
/**
* The first available constant id number.
*/
private int constantId = 1;
/**
* Creates a new parser file.
*
* @param gen the parser generator to use
* @param tokenizer the tokenizer file generator
* @param analyzer the analyzer file generator
*/
public JavaParserFile(JavaParserGenerator gen,
JavaTokenizerFile tokenizer,
JavaAnalyzerFile analyzer) {
int modifiers;
this.gen = gen;
this.file = gen.createJavaFile();
if (gen.getPublicAccess()) {
modifiers = JavaClass.PUBLIC;
} else {
modifiers = JavaClass.PACKAGE_LOCAL;
}
this.cls = new JavaClass(modifiers,
gen.getBaseName() + "Parser",
"RecursiveDescentParser");
this.initMethod = new JavaMethod(JavaMethod.PRIVATE,
"createPatterns",
"",
"void");
initializeCode(tokenizer, analyzer);
}
/**
* Initializes the source code objects.
*
* @param tokenizer the tokenizer file generator
* @param analyzer the analyzer file generator
*/
private void initializeCode(JavaTokenizerFile tokenizer,
JavaAnalyzerFile analyzer) {
JavaConstructor constr;
JavaMethod method;
String str;
// Add imports
file.addImport(new JavaImport("java.io", "Reader"));
file.addImport(new JavaImport("net.percederberg.grammatica.parser",
"ParserCreationException"));
file.addImport(new JavaImport("net.percederberg.grammatica.parser",
"ProductionPattern"));
file.addImport(new JavaImport("net.percederberg.grammatica.parser",
"ProductionPatternAlternative"));
file.addImport(new JavaImport("net.percederberg.grammatica.parser",
"RecursiveDescentParser"));
file.addImport(new JavaImport("net.percederberg.grammatica.parser",
"Tokenizer"));
// Add class
file.addClass(cls);
str = TYPE_COMMENT;
if (gen.getClassComment() != null) {
str += "\n\n" + gen.getClassComment();
}
cls.addComment(new JavaComment(str));
// Add file comment
str = file.toString() + "\n\n" + gen.getFileComment();
file.addComment(new JavaComment(JavaComment.BLOCK, str));
// Add constructor
constr = new JavaConstructor("Reader in");
cls.addConstructor(constr);
constr.addComment(new JavaComment(CONSTRUCTOR1_COMMENT));
constr.addThrows("ParserCreationException");
constr.addCode("super(in);");
constr.addCode("createPatterns();");
// Add constructor
constr = new JavaConstructor("Reader in, " + analyzer.getClassName() +
" analyzer");
cls.addConstructor(constr);
constr.addComment(new JavaComment(CONSTRUCTOR2_COMMENT));
constr.addThrows("ParserCreationException");
constr.addCode("super(in, analyzer);");
constr.addCode("createPatterns();");
// Add tokenizer factory method
method = new JavaMethod(JavaMethod.PROTECTED,
"newTokenizer",
"Reader in",
"Tokenizer");
method.addThrows("ParserCreationException");
method.addComment(new JavaComment(FACTORY_COMMENT));
method.addCode("return new " + tokenizer.getClassName() + "(in);");
cls.addMethod(method);
// Add init method
cls.addMethod(initMethod);
initMethod.addComment(new JavaComment(INIT_METHOD_COMMENT));
initMethod.addThrows("ParserCreationException");
initMethod.addCode("ProductionPattern pattern;");
initMethod.addCode("ProductionPatternAlternative alt;");
}
/**
* Adds a production constant definition to this file.
*
* @param pattern the production pattern
*/
public void addProductionConstant(ProductionPattern pattern) {
String constant;
JavaVariable var;
int modifiers;
if (pattern.isSynthetic()) {
constant = "SUBPRODUCTION_" + constantId;
modifiers = JavaVariable.PRIVATE + JavaVariable.STATIC +
JavaVariable.FINAL;
var = new JavaVariable(modifiers,
"int",
constant,
String.valueOf(constantId + 3000));
var.addComment(new JavaComment(PRODUCTION_COMMENT));
cls.addVariable(var);
constantNames.put(new Integer(pattern.getId()), constant);
constantId++;
}
}
/**
* Adds a production pattern definition to this file.
*
* @param pattern the production pattern
* @param constants the constants file generator
*/
public void addProduction(ProductionPattern pattern,
JavaConstantsFile constants) {
StringBuffer code;
String str;
// Create new pattern
code = new StringBuffer();
code.append("pattern = new ProductionPattern(");
code.append(getConstant(constants, pattern.getId()));
code.append(",\n");
code.append(" \"");
if (pattern.isSynthetic()) {
str = getConstant(constants, pattern.getId());
code.append(gen.getCodeStyle().getMixedCase(str, true));
} else {
code.append(pattern.getName());
}
code.append("\");");
initMethod.addCode("");
initMethod.addCode(code.toString());
// Set syntetic flag
if (pattern.isSynthetic()) {
initMethod.addCode("pattern.setSynthetic(true);");
}
// Create pattern rules
for (int i = 0; i < pattern.getAlternativeCount(); i++) {
addProductionAlternative(pattern.getAlternative(i),
constants);
}
// Add pattern to parser
initMethod.addCode("addPattern(pattern);");
}
/**
* Adds a production pattern alternative definition to the init
* method.
*
* @param alt the production pattern alternative
* @param constants the constants file generator
*/
private void addProductionAlternative(ProductionPatternAlternative alt,
JavaConstantsFile constants) {
ProductionPatternElement elem;
StringBuffer code;
initMethod.addCode("alt = new ProductionPatternAlternative();");
for (int i = 0; i < alt.getElementCount(); i++) {
elem = alt.getElement(i);
code = new StringBuffer();
code.append("alt.");
if (elem.isToken()) {
code.append("addToken(");
} else {
code.append("addProduction(");
}
code.append(getConstant(constants, elem.getId()));
code.append(", ");
code.append(elem.getMinCount());
code.append(", ");
if (elem.getMaxCount() == Integer.MAX_VALUE) {
code.append("-1");
} else {
code.append(elem.getMaxCount());
}
code.append(");");
initMethod.addCode(code.toString());
}
initMethod.addCode("pattern.addAlternative(alt);");
}
/**
* Returns the constant name for a specified pattern or token id.
*
* @param constants the constants file
* @param id the pattern id
*
* @return the constant name to use
*/
private String getConstant(JavaConstantsFile constants, int id) {
Integer value = new Integer(id);
if (constantNames.containsKey(value)) {
return (String) constantNames.get(value);
} else {
return constants.getConstant(id);
}
}
/**
* Writes the file source code.
*
* @throws IOException if the output file couldn't be created
* correctly
*/
public void writeCode() throws IOException {
file.writeCode(gen.getCodeStyle());
}
}