package org.codehaus.groovy.antlr.treewalker;
import antlr.collections.AST;
import org.codehaus.groovy.antlr.AntlrASTProcessor;
import org.codehaus.groovy.antlr.SourceBuffer;
import org.codehaus.groovy.antlr.UnicodeEscapingReader;
import org.codehaus.groovy.antlr.parser.GroovyLexer;
import org.codehaus.groovy.antlr.parser.GroovyRecognizer;
import java.io.ByteArrayOutputStream;
import java.io.PrintStream;
import java.io.StringReader;
import java.lang.reflect.Constructor;
public class TraversalTestHelper {
public String traverse(String input, Class visitorClass) throws Exception {
return traverse(input, visitorClass, null);
}
// todo - the visitor doesn't always take PrintStreams as constructor params! Could be a more reusable implementation than this...
public String traverse(String input, Class visitorClass, Boolean extraParam) throws Exception {
if (!Visitor.class.isAssignableFrom(visitorClass)) {
throw new RuntimeException("Invalid class for traversal: " + visitorClass.getName());
}
ByteArrayOutputStream baos = new ByteArrayOutputStream();
GroovyRecognizer parser;
SourceBuffer sourceBuffer = new SourceBuffer();
UnicodeEscapingReader unicodeReader = new UnicodeEscapingReader(new StringReader(input), sourceBuffer);
GroovyLexer lexer = new GroovyLexer(unicodeReader);
unicodeReader.setLexer(lexer);
parser = GroovyRecognizer.make(lexer);
parser.setSourceBuffer(sourceBuffer);
String[] tokenNames = parser.getTokenNames();
parser.compilationUnit();
AST ast = parser.getAST();
Class[] paramTypes;
Object[] params;
if (extraParam == null) {
paramTypes = new Class[]{PrintStream.class, String[].class};
params = new Object[]{new PrintStream(baos), tokenNames};
} else {
paramTypes = new Class[]{PrintStream.class, String[].class, Boolean.TYPE};
params = new Object[]{new PrintStream(baos), tokenNames, extraParam};
}
Constructor constructor = visitorClass.getConstructor(paramTypes);
Visitor visitor = (Visitor) constructor.newInstance(params);
AntlrASTProcessor traverser = new SourceCodeTraversal(visitor);
traverser.process(ast);
return new String(baos.toByteArray());
}
}