DirectiveCommentStartSensor.java

/**
 * Copyright (C) 2013-2016 The Rythm Engine project
 * for LICENSE and other details see:
 * https://github.com/rythmengine/rythmengine
 */
package org.rythmengine.internal.parser.build_in;

import org.rythmengine.extension.ICodeType;
import org.rythmengine.internal.IContext;
import org.rythmengine.internal.Token;
import org.rythmengine.internal.parser.RemoveLeadingLineBreakAndSpacesParser;
import org.rythmengine.utils.S;

import java.util.HashMap;
import java.util.Map;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

/**
 * Detect if a directive comment is reached and strip
 * it out from the parsing process
 * <p/>
 * <p>For example when <!-- @> is found the
 * <!-- should be stripped out</p>
 */
public class DirectiveCommentStartSensor extends RemoveLeadingLineBreakAndSpacesParser {

    public DirectiveCommentStartSensor(IContext context) {
        super(context);
    }

    private static Map<String, Pattern> patterns = new HashMap<String, Pattern>();

    @Override
    public Token go() {
        IContext ctx = ctx();
        if (ctx.insideDirectiveComment()) {
            return null;
            //raiseParseException("directive comment not closed");
        }
        ICodeType type = ctx.peekCodeType();
        while (null != type) {
            String sCommentStart = type.commentStart();
            if (!S.empty(sCommentStart)) {
                sCommentStart = S.escapeRegex(sCommentStart).toString();
                // try <!-- @ first
                String s = "(" + sCommentStart + "\\s*" + ")" + ctx.getDialect().a() + ".*";
                Pattern p = patterns.get(s);
                if (null == p) {
                    p = Pattern.compile(s, Pattern.DOTALL);
                    patterns.put(s, p);
                }
                Matcher m = p.matcher(remain());
                if (m.matches()) {
                    s = m.group(1);
                    ctx.step(s.length());
                    ctx.enterDirectiveComment();
                    return Token.EMPTY_TOKEN;
                }
                // try <!-- }
                s = "(" + sCommentStart + "\\s*)\\}.*";
                p = patterns.get(s);
                if (null == p) {
                    p = Pattern.compile(s, Pattern.DOTALL);
                    patterns.put(s, p);
                }
                m = p.matcher(remain());
                if (m.matches()) {
                    s = m.group(1);
                    ctx.step(s.length());
                    ctx.enterDirectiveComment();
                    return Token.EMPTY_TOKEN;
                }
            }
            type = type.getParent();
        }

        return null;
    }

    public static void main(String[] args) {
    }
}