Runtime-sink-file-path-or-none

Read the effective file path from a RuntimeSink only when it is actually file-backed.

This is the truthful companion to file_path(). Prefer it for diagnostics, branching, and recovery logic that must distinguish “not file-backed” from compatibility fallbacks.

Interface

pub fn RuntimeSink::file_path_or_none(self : RuntimeSink) -> String? {

input

• self : RuntimeSink - Runtime sink whose file path should be inspected.

output

• String? - Some(path) when the runtime sink is file-backed, otherwise None.

Explanation

Detailed rules explaining key parameters and behaviors

• Plain File runtime variants return Some(path).
• QueuedFile runtime variants forward the wrapped inner file sink path as Some(path).
• Non-file runtime variants return None.
• This helper is observation-only and does not mutate runtime state.

How to Use

Here are some specific examples provided.

When Need Truthful File-backed Detection

When code should branch only if file semantics really exist:

match sink.file_path_or_none() {
  Some(path) => println(path)
  None => ()
}

In this example, None means the runtime sink is not file-backed.

When Need Path Diagnostics Without Fallback Values

When support output should avoid compatibility placeholders:

let maybe_path = sink.file_path_or_none()

In this example, callers can keep “no file semantics” distinct from a real path.

Error Case

e.g.:

• If the runtime sink is not file-backed, the method returns None.

• If callers need the broader file snapshot or queue context, prefer file_state_or_none() or file_runtime_state().

Notes

1. Prefer this helper over file_path() for truthful runtime diagnostics.

2. file_path() remains available as the compatibility fallback API.