com.github.uscexp.grappa.extension.codegenerator.PegParserGenerator Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of grappa.extension Show documentation
Extension for parboiled/grappa parser.
The newest version!
/*
 * Copyright (C) 2014 - 2016 by haui - all rights reserved
 */
package com.github.uscexp.grappa.extension.codegenerator;

import java.io.File;
import java.io.IOException;
import java.nio.charset.Charset;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.util.Date;
import java.util.logging.Level;
import java.util.logging.Logger;

import com.github.fge.grappa.Grappa;
import com.github.fge.grappa.parsers.BaseParser;
import com.github.uscexp.grappa.extension.exception.AstInterpreterException;
import com.github.uscexp.grappa.extension.exception.PegParserGeneratorException;
import com.github.uscexp.grappa.extension.interpreter.AstInterpreter;
import com.github.uscexp.grappa.extension.interpreter.ProcessStore;
import com.github.uscexp.grappa.extension.nodes.AstTreeNode;
import com.github.uscexp.grappa.extension.parser.Parser;
import com.github.uscexp.grappa.extension.parser.peg.PegParser;
import com.google.common.base.Preconditions;
import com.sun.codemodel.JClass;
import com.sun.codemodel.JClassAlreadyExistsException;
import com.sun.codemodel.JCodeModel;
import com.sun.codemodel.JDefinedClass;
import com.sun.codemodel.JDocComment;

/**
 * The {@link PegParserGenerator} generates a {@link BaseParser} extended parser java class file, from a given Parser Expression Grammar
 * (PEG) file. The allowed PEG syntax is based on Bryan Ford's definitions (http://bford.info/pub/lang/peg).
 *
 * @author  haui
 */
public class PegParserGenerator {

	private static Logger logger = Logger.getLogger(PegParserGenerator.class.getName());

	public static final long CLOSE = "close".hashCode();
	public static final long OPEN = "open".hashCode();
	public static final String CODE_MODEL = "codeModel";
	public static final String DEFINED_CLASS = "definedClass";
	private File file = null;

	private PegParser parser;
	private AstTreeNode rootNode;
	private String parserClassString;
	private String genericTypeName;

	private AstInterpreter astInterpreter;

	public void generateParserFromFile(String parserClassString, String genericTypeName, String sourceOutputPath, String pegInputPath,
			Charset encoding)
		throws PegParserGeneratorException, AstInterpreterException {
		String input = null;

		if (encoding == null)
			encoding = Charset.defaultCharset();

		file = new File(pegInputPath);

		if (!file.exists()) {
			throw new PegParserGeneratorException(String.format("File %s does not exist!", pegInputPath));
		}

		try {
			byte[] encoded = Files.readAllBytes(Paths.get(file.getAbsolutePath()));
			input = new String(encoded, encoding);
		} catch (IOException e) {
			throw new PegParserGeneratorException(String.format("File %s couldn't be read!", pegInputPath), e);
		}

		generateParserFromString(parserClassString, genericTypeName, sourceOutputPath, input);
	}

	public void generateParserFromString(String parserClassString, String genericTypeName, String sourceOutputPath, String pegInput)
		throws PegParserGeneratorException, AstInterpreterException {
		Preconditions.checkNotNull(pegInput);

		parser = Grappa.createParser(PegParser.class);

		rootNode = Parser.parseInput(PegParser.class, parser.grammar(), pegInput, true);

		generateParserClassFile(parserClassString, genericTypeName, sourceOutputPath);

	}

	private void generateParserClassFile(String parserClassString, String genericTypeName, String sourceOutputPath)
		throws AstInterpreterException, PegParserGeneratorException {
		astInterpreter = new AstInterpreter<>();

		Long id = new Date().getTime();
		Long idOpen = id + OPEN;
		try {
			this.parserClassString = parserClassString;
			this.genericTypeName = genericTypeName;
			generateCode(sourceOutputPath, id, idOpen);
		} catch (JClassAlreadyExistsException | IOException e) {
			throw new PegParserGeneratorException("PEG parser generator unexpected error", e);
		} finally {
			astInterpreter.cleanUp(id);
			astInterpreter.cleanUp(idOpen);
		}
	}

	private void generateCode(String sourceOutputPath, Long id, Long idOpen)
		throws JClassAlreadyExistsException, AstInterpreterException, IOException {
		JCodeModel codeModel = new JCodeModel();
		ProcessStore processStore = ProcessStore.getInstance(id);
		ProcessStore