core/src/main/java/coffee/liz/lambda/bind/Tick.java


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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;
    }
}