package trees.expressiontrees;

public abstract class Token { }

class Operation extends Token {
	private final String symbol;
	private final int priority;
	
	static final Operation L_BRACE = new Operation("(", 1);
	static final Operation PLUS = new Operation("+", 5);
	static final Operation MINUS = new Operation("-", 5);
	static final Operation MULT = new Operation("*", 10);
	static final Operation DIV = new Operation("/", 10);
	static final Operation R_BRACE = new Operation(")", 0);
	
	
	private Operation(String s, int priority) {
		this.symbol = s;
		this.priority = priority;
	}
	
	int priority() {
		return priority;
	}
	
	public String toString() {
		return symbol;
	}
}

class Operand extends Token {
	private int value;
	
	Operand(int val) {
		value = val;
	}
	
	int value() {
		return value;
	}
	
	public String toString() {
		return "" + value;
	}
}