Stack safe task array

[florianbepunkt]

I saw that #1345 has been merged, but I do not fully understand how to use sequenceArray/sequenceA or where to find it. I believe the documentation of the pr is outdated.

I have an array of about 10.000 items that are converted. Each conversion requires an api call. The following code works for about 2.000 items, but if the array is larger I get RangeError: Maximum call stack size exceeded

How can I make the following stack-safe? I believe A.sequence(T.ApplicativeSeq)is the culprit

pipe(
    paymentTransactions,
    A.map(convertTransaction),
    A.sequence(T.ApplicativeSeq),
    mergeConversionResultsAndErrors,
    T.map(
      flow(
        S.mapLeft(flow(A.map(serializeConversionFailureToCsv), O.fromPredicate(A.isNonEmpty))),
        S.map(flow(A.map(serializePaymentTransactionToDatevCsv), O.fromPredicate(A.isNonEmpty))),
        (r) => ({ erroneousLines: r.left, convertedLines: r.right }),
      ),
    ),
  );

EDIT: changing A.sequence(T.ApplicativeSeq), to T.sequenceArray, does not work, as T.sequenceArray, returns a readonly output (while A.sequence does not)

[DenisFrezzato]

As you wrote, you have to replace A.sequence(T.ApplicativeSeq) with T.sequenceArray. If you're not fine with a readonly array, you can use toArray from ReadonlyArray module.