forked from jasder/antlr
80 lines
2.9 KiB
Java
80 lines
2.9 KiB
Java
/*
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[The "BSD license"]
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Copyright (c) 2011 Terence Parr
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All rights reserved.
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Redistribution and use in source and binary forms, with or without
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modification, are permitted provided that the following conditions
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are met:
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1. Redistributions of source code must retain the above copyright
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notice, this list of conditions and the following disclaimer.
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2. Redistributions in binary form must reproduce the above copyright
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notice, this list of conditions and the following disclaimer in the
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documentation and/or other materials provided with the distribution.
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3. The name of the author may not be used to endorse or promote products
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derived from this software without specific prior written permission.
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THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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import org.antlr.v4.runtime.ANTLRFileStream;
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import org.antlr.v4.runtime.CommonTokenStream;
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import org.antlr.v4.runtime.ParserRuleContext;
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import org.antlr.v4.runtime.Token;
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import org.antlr.v4.runtime.tree.ParseTreeVisitor;
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import org.antlr.v4.runtime.tree.ParseTreeWalker;
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public class TestVisitor {
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public static class MyVisitor extends ParseTreeVisitor<Integer> implements AVisitor<Integer> {
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@Override
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public Integer visit(AParser.AddContext ctx) {
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return ctx.e(0).dispatch(this) + ctx.e(1).dispatch(this);
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}
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@Override
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public Integer visit(AParser.IntContext ctx) {
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return Integer.valueOf(ctx.INT().getText());
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}
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@Override
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public Integer visit(AParser.MultContext ctx) {
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// return ctx.e(0).dispatch(this) * ctx.e(1).dispatch(this);
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return visit(ctx.e(0)) * visit(ctx.e(1));
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}
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@Override
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public Integer visit(AParser.ParensContext ctx) {
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return ctx.e().dispatch(this);
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}
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@Override
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public Integer visit(AParser.sContext ctx) {
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return ctx.e().dispatch(this);
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}
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}
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public static void main(String[] args) throws Exception {
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ALexer lexer = new ALexer(new ANTLRFileStream(args[0]));
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CommonTokenStream tokens = new CommonTokenStream(lexer);
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AParser p = new AParser(tokens);
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p.setBuildParseTree(true);
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ParserRuleContext<Token> t = p.s();
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System.out.println("tree = "+t.toStringTree(p));
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MyVisitor visitor = new MyVisitor();
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Integer result = visitor.visit(t);
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// Integer result = t.dispatch(visitor);
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System.out.println("result from tree walk = " + result);
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}
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}
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