rhaj/rhai_engine/rhaibook/rust/context-restore.md

Advanced Usage – Restore NativeCallContext

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The [NativeCallContext] type encapsulates the entire context of a script up to the particular point of the native Rust function call.

The data inside a [NativeCallContext] can be stored (as a type NativeCallContextStore) for later use, when a new [NativeCallContext] can be constructed based on these stored data.

A reconstructed [NativeCallContext] acts almost the same as the original instance, so it is possible to suspend the evaluation of a script, and to continue at a later time with a new [NativeCallContext].

Doing so requires the [internals] feature to access internal APIs.

Step 1: Store NativeCallContext data

// Store context for later use
let context_data = context.store_data();

// ... store 'context_data' somewhere ...
secret_database.push(context_data);

Step 2: Restore NativeCallContext

// ... do something else ...

// Restore the context
let context_data = secret_database.get();

let new_context = context_data.create_context(&engine);