source: trunk/yao/share/antlr-2.7.7/examples/java/pascal/Scope.java @ 1

import java.util.Hashtable;
import java.util.Enumeration;
import java.io.*;

/** A set of symbols (type defs and/or variables) */
public class Scope implements Serializable {
        protected Scope parent;

        protected Hashtable symbols = new Hashtable();

        public Scope(Scope parent) {
                this.parent = parent;
        }

        public void addSymbol(Symbol s) {
                if ( s.getName() != null ) {
                        symbols.put(s.getName(), s);
                }
        }

        /** Look up name in this scope or parent */
        public Symbol resolve(String name) {
                Symbol s = (Symbol)symbols.get(name);
                if ( s==null ) {
                        return parent.resolve(name);
                }
                return s;
        }

        public String toString() {
                return "Scope=["+symbols+"]"+(parent==null?"<root>":"");
        }
}