package coffee.liz.lambda.bind;

import coffee.liz.lambda.eval.Environment;
import coffee.liz.lambda.eval.Value;
import lombok.Getter;

import java.util.concurrent.atomic.AtomicInteger;

/**
 * Identity function that has a side effect which internally counts invocations.
 */
@Getter
public class Tick implements ExternalBinding {
	private final String name = "Tick";
	private final AtomicInteger counter = new AtomicInteger(0);

	@Override
	public Value apply(final Environment environment, final Value value) {
		counter.incrementAndGet();
		return value;
	}
}