Quiver delay function composition 1

quiver_retry_1.dart

typedef Object OnErrorFunc(Object err, int retry, Duration elapsed);
typedef Duration RetryDelayFunc(Object err, int retry, Duration elapsed);
Future start(
    AttemptFunc attempt, {
    OnErrorFunc onError: retriesInfinite,
    RetryDelayFunc retryDelay: delayNone,
    Stopwatch runTime})

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import 'package:quiver/retry.dart' as retry;

var limited = retry.makeRetriesLimited(10, new Duration(seconds: 10));

onError(err, iteration, elapsed) =>
    is404(err) ? err : limited(err, iteration, elapsed);

delayFn(err, iteration, elapsed) =>
    is503(err)
      ? retry.randomDelay(new Duration(seconds: 1), 0.8)
      : retry.capDelay(retry.randomDelay(new Duration(seconds: 1), 0.4),
          const Duration(milliseconds: 1200));

retry.start(doSomething, onError: onError, retryDelay: delayFn);