SymbolTable.java

import java.util.*;

public class SymbolTable 
{
        Map <String, Integer> OffsetMap = new HashMap <String,Integer>();
        
	public void insert( String s, int address ) 
        {
                if( !OffsetMap.containsValue(address) ) 
                        OffsetMap.put(s,address);
                else 
                        throw new IllegalArgumentException("Riferimento a una porzione di memoria già occupata da un'altra variabile");
	}

	public int lookupAddress ( String s ) 
        {
                if( OffsetMap.containsKey(s) ) 
                        return OffsetMap.get(s);
                else
                        return -1;
	}
}