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File-sink-set-append-mode ​

Update the append-mode policy used by a FileSink. This helper changes future reopen behavior on the concrete sink without forcing an immediate reopen.

Interface ​

moonbit
pub fn FileSink::set_append_mode(self : FileSink, append : Bool) -> Unit {

input ​

  • self : FileSink - File sink whose append-mode policy should change.
  • append : Bool - New append-mode policy.

Explanation ​

Detailed rules explaining key parameters and behaviors

  • This method updates stored policy only.
  • It does not force an immediate reopen.
  • The new value affects later reopen behavior.
  • The sink path and current rotation policy are left unchanged.

How to Use ​

Here are some specific examples provided.

When Need To Change Future Reopen Behavior ​

When direct recovery code should later prefer append mode explicitly:

moonbit
sink.set_append_mode(true)

In this example, later reopen operations use the updated append policy.

When Want To Separate Policy Mutation From Reopen Timing ​

When code should update policy now and reopen later:

moonbit
sink.set_append_mode(false)
ignore(sink.reopen_with_current_policy())

In this example, policy mutation and reopen timing remain separate decisions.

Error Case ​

e.g.:

  • If callers need an immediate reopen as part of the same operation, one of the reopen helpers should be used afterward.

  • This method does not itself prove that the sink is currently available or writable.

Notes ​

  1. This helper changes stored policy, not live file-handle state by itself.

  2. It is useful when direct file-sink recovery logic wants to stage reopen behavior in advance.

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