Function load_optional 

pub async fn load_optional<A: Aggregator, E: Executor>(
    executor: &E,
    id: impl Into<String>,
) -> Result<Option<LoadResult<A>>, ReadError>

Load an aggregate by replaying its events, returning None if not found

This is a convenience wrapper around load that returns None instead of ReadError::NotFound when the aggregate doesn’t exist. This is useful when you want to handle missing aggregates as a normal case rather than an error.

Parameters

• executor: The event store executor (database connection)
• id: The aggregate ID to load

Returns

Returns Ok(Some(LoadResult)) if the aggregate exists, Ok(None) if not found, or an error for other failure cases.

Errors

• ReadError::TooManyEvents if there are too many events to process (>10 batches)
• ReadError::BincodeDecode if event deserialization fails
• ReadError::Unknown for other database or system errors

Note: Unlike load, this function does NOT return ReadError::NotFound.

Examples

use evento::load_optional;

async fn get_user_if_exists(executor: &evento::Sqlite, user_id: &str) -> anyhow::Result<Option<User>> {
    match load_optional::<User, _>(executor, user_id).await? {
        Some(result) => {
            println!("Found user at version {}", result.event.version);
            Ok(Some(result.item))
        }
        None => {
            println!("User not found");
            Ok(None)
        }
    }
}