Consider tail recursion #62
Description
We've removed the tail recursion because it was hard to consolidate it into yield! (it was instead done with return!, which has no place in taskSeq).
However, today I helped someone with some code that he considered for taskSeq which had the following approach:
let getPoliciesAsync policyid =
asyncSeq{
use connection = new NpgsqlConnection(npgsqlConnectionStringBuilder.ConnectionString)
use command = new NpgsqlCommand($"SELECT policy_data FROM policy.tbl_policy where policy_id = {Sql.uuid policyid};", connection)
let! reader = command.ExecuteReaderAsync() |> Async.AwaitTask
let rec someRec() = asyncSeq{
let! rowExists = reader.ReadAsync() |> Async.AwaitTask
if rowExists then
yield {| dt1 = reader.GetString(0) |}
yield! someRec()
}
yield! someRec()
} |> AsyncSeq.toAsyncEnumAs you can see, it uses asyncSeq, but also: it is recursive. The same approach with taskSeq would likely be more performant, however, if there are a lot of rows, this becomes problematic. This code can be rewritten with a loop, though.
@dsyme, sharing this with you in case we want to revisit this at some point.