ASTLeaf.java

package jp.ac.aiit.jointry.services.lang.ast;

import java.util.Iterator;
import java.util.ArrayList;
import jp.ac.aiit.jointry.services.lang.parser.Environment;
import jp.ac.aiit.jointry.services.lang.parser.Token;
import jp.ac.aiit.jointry.util.JoinTryException;

public class ASTLeaf extends ASTree {

    private static ArrayList<ASTree> empty = new ArrayList<ASTree>();
    protected Token token;

    public ASTLeaf(Token t) {
        token = t;
    }

    public ASTree child(int i) {
        throw new IndexOutOfBoundsException();
    }

    public int numChildren() {
        return 0;
    }

    public Iterator<ASTree> children() {
        return empty.iterator();
    }

    public String toString() {
        return token.getText();
    }

    public String location() {
        return "at line " + token.getLineNumber();
    }

    public Token token() {
        return token;
    }

    public Object eval(Environment env) {
        throw new JoinTryException("cannot eval: " + toString(), this);
    }
}