antlr-3.4/tool/src/test/java/org/antlr/test/TestTreeIterator.java

/*
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 *  Copyright (c) 2010 Terence Parr
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package org.antlr.test;

import org.antlr.runtime.tree.*;
import org.junit.Test;

import static org.junit.Assert.assertEquals;

public class TestTreeIterator {
    static final String[] tokens = new String[] {
        "<invalid>", "<EOR>", "<DOWN>", "<UP>", "A", "B", "C", "D", "E", "F", "G"
    };

    @Test public void testNode() {
        TreeAdaptor adaptor = new CommonTreeAdaptor();
        TreeWizard wiz = new TreeWizard(adaptor, tokens);
        CommonTree t = (CommonTree)wiz.create("A");
        TreeIterator it = new TreeIterator(t);
        StringBuffer buf = toString(it);
        String expecting = "A EOF";
        String found = buf.toString();
        assertEquals(expecting, found);
    }

    @Test public void testFlatAB() {
        TreeAdaptor adaptor = new CommonTreeAdaptor();
        TreeWizard wiz = new TreeWizard(adaptor, tokens);
        CommonTree t = (CommonTree)wiz.create("(nil A B)");
        TreeIterator it = new TreeIterator(t);
        StringBuffer buf = toString(it);
        String expecting = "nil DOWN A B UP EOF";
        String found = buf.toString();
        assertEquals(expecting, found);
    }

    @Test public void testAB() {
        TreeAdaptor adaptor = new CommonTreeAdaptor();
        TreeWizard wiz = new TreeWizard(adaptor, tokens);
        CommonTree t = (CommonTree)wiz.create("(A B)");
        TreeIterator it = new TreeIterator(t);
        StringBuffer buf = toString(it);
        String expecting = "A DOWN B UP EOF";
        String found = buf.toString();
        assertEquals(expecting, found);
    }

    @Test public void testABC() {
        TreeAdaptor adaptor = new CommonTreeAdaptor();
        TreeWizard wiz = new TreeWizard(adaptor, tokens);
        CommonTree t = (CommonTree)wiz.create("(A B C)");
        TreeIterator it = new TreeIterator(t);
        StringBuffer buf = toString(it);
        String expecting = "A DOWN B C UP EOF";
        String found = buf.toString();
        assertEquals(expecting, found);
    }

    @Test public void testVerticalList() {
        TreeAdaptor adaptor = new CommonTreeAdaptor();
        TreeWizard wiz = new TreeWizard(adaptor, tokens);
        CommonTree t = (CommonTree)wiz.create("(A (B C))");
        TreeIterator it = new TreeIterator(t);
        StringBuffer buf = toString(it);
        String expecting = "A DOWN B DOWN C UP UP EOF";
        String found = buf.toString();
        assertEquals(expecting, found);
    }

    @Test public void testComplex() {
        TreeAdaptor adaptor = new CommonTreeAdaptor();
        TreeWizard wiz = new TreeWizard(adaptor, tokens);
        CommonTree t = (CommonTree)wiz.create("(A (B (C D E) F) G)");
        TreeIterator it = new TreeIterator(t);
        StringBuffer buf = toString(it);
        String expecting = "A DOWN B DOWN C DOWN D E UP F UP G UP EOF";
        String found = buf.toString();
        assertEquals(expecting, found);
    }

    @Test public void testReset() {
        TreeAdaptor adaptor = new CommonTreeAdaptor();
        TreeWizard wiz = new TreeWizard(adaptor, tokens);
        CommonTree t = (CommonTree)wiz.create("(A (B (C D E) F) G)");
        TreeIterator it = new TreeIterator(t);
        StringBuffer buf = toString(it);
        String expecting = "A DOWN B DOWN C DOWN D E UP F UP G UP EOF";
        String found = buf.toString();
        assertEquals(expecting, found);

        it.reset();
        buf = toString(it);
        expecting = "A DOWN B DOWN C DOWN D E UP F UP G UP EOF";
        found = buf.toString();
        assertEquals(expecting, found);
    }

    protected static StringBuffer toString(TreeIterator it) {
        StringBuffer buf = new StringBuffer();
        while ( it.hasNext() ) {
            CommonTree n = (CommonTree)it.next();
            buf.append(n);
            if ( it.hasNext() ) buf.append(" ");
        }
        return buf;
    }
}