ParseTreeUtils.java

package parsing;

import org.antlr.v4.runtime.tree.ParseTree;

public class ParseTreeUtils
{
	public static String childTokenString(ParseTree ctx)
	{
		// TODO: Optimize this. Strings are immutable

		// The reason we don't just call ctx.getText()
		// here is because it removes whitespace, making
		// 'inti' from 'int i'.

		if (ctx == null)
			return "";

		int nChildren = ctx.getChildCount();

		if (nChildren == 0)
		{
			return ctx.getText();
		}

		String retval = "";

		for (int i = 0; i < nChildren; i++)
		{
			ParseTree child = ctx.getChild(i);
			String childText = childTokenString(child);
			if (!childText.equals(""))
			{
				retval += childText + " ";
			}
		}

		if (retval.length() > 0)
			retval = retval.substring(0, retval.length() - 1);
		return retval;
	}
}