public class VariableExpression extends Expression {

	private String varname;
	private SymbolTable table;
	
	public VariableExpression(String var, SymbolTable s) {
		this.varname = var;
		this.table = s;
	}
	
	@Override
	int interpret() {
		if (!table.isDefined(varname)) {
			throw new java.lang.Error("Uh oh. Undefined variable...");
		}
		return Integer.parseInt(table.lookupVal(varname));
	}
	
	public String toString() {
		return varname;
	}

}