Async-runtime-mode-label

Convert AsyncRuntimeMode into a stable string label. This helper is useful when runtime mode should be logged, serialized, or exposed through human-readable diagnostics.

Interface

pub fn async_runtime_mode_label(mode : AsyncRuntimeMode) -> String {}

input

• mode : AsyncRuntimeMode - Runtime mode enum value.

output

• String - Stable mode label such as native_worker or compatibility.

Explanation

Detailed rules explaining key parameters and behaviors

• The returned value is intended for diagnostics and stable output, not just debugging prints.
• It keeps mode serialization logic in one place.
• This helper is used by async runtime JSON helpers.
• async_runtime_state_to_json(...) serializes the mode field through this helper, so runtime snapshots and direct label rendering share the same canonical text.
• Labels are more stable for telemetry and docs than ad hoc manual matching at call sites.
• The current canonical labels are exactly native_worker for NativeWorker and compatibility for Compatibility.
• This helper is only a pure enum-to-string mapping. It does not inspect the active backend or verify that the supplied enum still matches the current runtime environment.

How to Use

Here are some specific examples provided.

When Need A Stable Log Label

When the mode should be included in structured or plain logs:

println(async_runtime_mode_label(async_runtime_mode()))

In this example, the label is directly usable in diagnostics.

When Build Custom Serialization

When callers want to embed the mode into their own payloads:

let label = async_runtime_mode_label(async_runtime_mode())

In this example, code gets a stable string without duplicating enum matching logic.

Error Case

e.g.:

• This API assumes a valid AsyncRuntimeMode input and does not expose a normal runtime error path.

• If callers need the current backend-derived mode rather than a previously stored enum value, they must call async_runtime_mode() first and then label that result.

• If callers need the whole runtime object rather than a string label, use async_runtime_state().

Notes

1. Use this helper when mode values should be rendered as stable text instead of manual enum matching.

2. async_runtime_state_to_json(...) uses these exact labels when serializing runtime snapshots.