📝 document runtime sink append path methods

2026-07-26 09:52:31 +00:00 · 2026-06-13 22:59:12 +08:00
parent bf7512d113
commit 65605f6b59
4 changed files with 228 additions and 0 deletions
@@ -0,0 +1,74 @@
+---
+name: runtime-sink-file-path
+group: api
+category: runtime
+update-time: 20260613
+description: Read the effective file path used by a file-backed RuntimeSink.
+key-word:
+    - runtime
+    - sink
+    - file
+    - public
+---
+
+## Runtime-sink-file-path
+
+Read the effective file path used by a file-backed `RuntimeSink`. This helper is useful for diagnostics, support output, and confirming which direct runtime file sink is active.
+
+### Interface
+
+```moonbit
+pub fn RuntimeSink::file_path(self : RuntimeSink) -> String {
+```
+
+#### input
+
+- `self : RuntimeSink` - Runtime sink whose file path should be inspected.
+
+#### output
+
+- `String` - Effective runtime file path, or an empty string for non-file sinks.
+
+### Explanation
+
+Detailed rules explaining key parameters and behaviors
+
+- Plain `File` runtime variants return their current file path.
+- `QueuedFile` runtime variants forward the wrapped inner file sink path.
+- Non-file runtime variants return an empty string.
+- This helper is observation-only and does not modify file state.
+
+### How to Use
+
+Here are some specific examples provided.
+
+#### When Need Direct Runtime Path Diagnostics
+
+When code owns a `RuntimeSink` and should show which file is active:
+```moonbit
+println(sink.file_path())
+```
+
+In this example, operators can verify the effective destination path directly from the runtime sink.
+
+#### When Build Support Output From A Runtime Sink
+
+When application state dumps should include file destination info:
+```moonbit
+let path = sink.file_path()
+```
+
+In this example, the path can be surfaced without reading broader runtime state.
+
+### Error Case
+
+e.g.:
+- If the runtime sink is not file-backed, the method returns an empty string.
+
+- If callers need richer file status than just the path, `file_state()` or `file_runtime_state()` is the better API.
+
+### Notes
+
+1. Use this helper for direct runtime path visibility on `RuntimeSink` values.
+
+2. Empty string usually means the runtime sink is not file-backed.