de.uni.bremen.monty.moco.util.ParseTreePrinter.java Source code

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Here is the source code for de.uni.bremen.monty.moco.util.ParseTreePrinter.java

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/*
 * moco, the Monty Compiler
 * Copyright (c) 2013-2014, Monty's Coconut, All rights reserved.
 *
 * This file is part of moco, the Monty Compiler.
 *
 * moco is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public
 * License as published by the Free Software Foundation; either
 * version 3.0 of the License, or (at your option) any later version.
 *
 * moco 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
 * General Public License for more details.
 *
 * Linking this program and/or its accompanying libraries statically or
 * dynamically with other modules is making a combined work based on this
 * program. Thus, the terms and conditions of the GNU General Public License
 * cover the whole combination.
 *
 * As a special exception, the copyright holders of moco give
 * you permission to link this programm and/or its accompanying libraries
 * with independent modules to produce an executable, regardless of the
 * license terms of these independent modules, and to copy and distribute the
 * resulting executable under terms of your choice, provided that you also meet,
 * for each linked independent module, the terms and conditions of the
 * license of that module.
 *
 * An independent module is a module which is not
 * derived from or based on this program and/or its accompanying libraries.
 * If you modify this library, you may extend this exception to your version of
 * the program or library, but you are not obliged to do so. If you do not wish
 * to do so, delete this exception statement from your version.
 *
 * You should have received a copy of the GNU General Public
 * License along with this library.
 */
package de.uni.bremen.monty.moco.util;

import org.antlr.v4.runtime.Parser;
import org.antlr.v4.runtime.ParserRuleContext;
import org.antlr.v4.runtime.misc.Utils;
import org.antlr.v4.runtime.tree.ErrorNode;
import org.antlr.v4.runtime.tree.ParseTreeListener;
import org.antlr.v4.runtime.tree.TerminalNode;
import org.antlr.v4.runtime.tree.Trees;

import java.util.Arrays;
import java.util.List;

public class ParseTreePrinter implements ParseTreeListener {
    private final List<String> ruleNames;
    private final StringBuilder builder = new StringBuilder();
    private int intend = 0;
    private ParserRuleContext lastOne;
    private boolean intended;

    public ParseTreePrinter(Parser parser) {
        this.ruleNames = Arrays.asList(parser.getRuleNames());
    }

    @Override
    public void visitTerminal(TerminalNode node) {
        if (builder.length() > 0) {
            builder.append(' ');
        }

        append(Utils.escapeWhitespace(Trees.getNodeText(node, ruleNames), false));
    }

    @Override
    public void visitErrorNode(ErrorNode node) {
        if (builder.length() > 0) {
            builder.append(' ');
        }

        append(Utils.escapeWhitespace(Trees.getNodeText(node, ruleNames), false));
    }

    @Override
    public void enterEveryRule(ParserRuleContext ctx) {
        builder.append("\n");
        intended = false;

        if (builder.length() > 0) {
            builder.append(' ');
        }

        if (!ctx.equals(lastOne)) {
            intend++;
        }

        int ruleIndex = ctx.getRuleIndex();
        String ruleName;
        if (ruleIndex >= 0 && ruleIndex < ruleNames.size()) {
            ruleName = ruleNames.get(ruleIndex);
        } else {
            ruleName = Integer.toString(ruleIndex);
        }

        append(ruleName);
        lastOne = ctx;
    }

    private void append(String ruleName) {
        if (!intended) {
            for (int i = 0; i < intend; i++) {
                builder.append(' ');
            }
            intended = true;
        }
        builder.append(ruleName);
    }

    @Override
    public void exitEveryRule(ParserRuleContext ctx) {
        if (ctx.getChildCount() > 0) {
            intend--;
        }
    }

    @Override
    public String toString() {
        return builder.toString();
    }
}