org.eclipse.xtend.core.parser.JFlexGeneratorFragment.java Source code

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Here is the source code for org.eclipse.xtend.core.parser.JFlexGeneratorFragment.java

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/*******************************************************************************
 * Copyright (c) 2013 itemis AG (http://www.itemis.eu) and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *******************************************************************************/
package org.eclipse.xtend.core.parser;

import java.io.IOException;
import java.io.InputStreamReader;
import java.nio.charset.Charset;
import java.util.List;

import org.eclipse.emf.mwe2.runtime.Mandatory;
import org.eclipse.xpand2.XpandExecutionContext;
import org.eclipse.xpand2.XpandFacade;
import org.eclipse.xtext.Grammar;
import org.eclipse.xtext.GrammarUtil;
import org.eclipse.xtext.generator.AbstractGeneratorFragment;
import org.eclipse.xtext.generator.Generator;
import org.eclipse.xtext.generator.NewlineNormalizer;
import org.eclipse.xtext.generator.parser.antlr.XtextAntlrGeneratorFragment;
import org.eclipse.xtext.generator.parser.antlr.XtextAntlrUiGeneratorFragment;

import com.google.common.collect.Lists;
import com.google.common.io.CharStreams;

/**
 * @author Sebastian Zarnekow - Initial contribution and API
 */
public class JFlexGeneratorFragment extends AbstractGeneratorFragment {

    private JFlexMain main;

    private String patternPath;

    private String additionalRulePath;

    private boolean ui = false;

    @Mandatory
    public void setJFlexMain(JFlexMain main) {
        this.main = main;
    }

    public void setUi(boolean ui) {
        this.ui = ui;
    }

    /**
     * @since 2.7
     */
    protected String getEncoding(XpandExecutionContext xpt, String outlet) {
        return xpt.getOutput().getOutlet(outlet).getFileEncoding();
    }

    @Override
    public void generate(Grammar grammar, XpandExecutionContext ctx) {
        final String srcGenPath;
        final String directory;
        final String template;
        final String encoding;
        if (!ui) {
            srcGenPath = ctx.getOutput().getOutlet(Generator.SRC_GEN).getPath();
            directory = srcGenPath + '/'
                    + getNaming().asPath(getNaming().basePackageRuntime(grammar) + ".parser.antlr.internal");
            template = getTemplate() + "::generate";
            encoding = getEncoding(ctx, Generator.SRC_GEN);
        } else {
            srcGenPath = ctx.getOutput().getOutlet(Generator.SRC_GEN_IDE).getPath();
            directory = srcGenPath + '/'
                    + getNaming().asPath(getNaming().basePackageIde(grammar) + ".contentassist.antlr.internal");
            template = getTemplate() + "::generateUI";
            encoding = getEncoding(ctx, Generator.SRC_GEN_IDE);
        }
        XpandFacade.create(ctx).evaluate2(template, grammar, getParameters(grammar));
        String fileName = "Internal" + GrammarUtil.getSimpleName(grammar) + "Flexer.flex";
        String javaFileName = directory + "/" + "Internal" + GrammarUtil.getSimpleName(grammar) + "Flexer.java";
        main.runJFlex(new String[] { "-d", directory, directory + "/" + fileName });
        Charset charset = Charset.forName(encoding);
        String javaCode = readFileIntoString(javaFileName, charset);
        javaCode = new NewlineNormalizer(getNaming().getLineDelimiter()).normalizeLineDelimiters(javaCode);
        javaCode = removeTimestamps(javaCode);
        writeStringIntoFile(javaFileName, javaCode, charset);
    }

    private String removeTimestamps(String javaCode) {
        int timestampEnd = javaCode.indexOf("*/");
        int commentStart = javaCode.indexOf("/*", timestampEnd);
        String result = javaCode.substring(commentStart);
        int timestampStart = result.indexOf("* on");
        timestampEnd = result.indexOf("from the specification file", timestampStart);
        result = result.substring(0, timestampStart + 2) + result.substring(timestampEnd);
        return result;
    }

    public void setPatternPath(String patternPath) {
        this.patternPath = patternPath;
    }

    public void setAdditionalRulePath(String rulePath) {
        this.additionalRulePath = rulePath;
    }

    @Override
    protected List<Object> getParameters(Grammar grammar) {
        String parserName = ui ? XtextAntlrUiGeneratorFragment.getGrammarFileName(grammar, getNaming())
                : XtextAntlrGeneratorFragment.getGrammarFileName(grammar, getNaming());
        return Lists.<Object>newArrayList(read(patternPath), read(additionalRulePath), parserName);
    }

    private String read(final String path) {
        if (path != null) {
            try {
                InputStreamReader reader = new InputStreamReader(getClass().getResourceAsStream(path),
                        "ISO-8859-1");
                try {
                    String patterns = CharStreams.toString(reader);
                    return patterns;
                } finally {
                    reader.close();
                }
            } catch (IOException e) {
                throw new RuntimeException(e);
            }
        }
        return null;
    }

}