option-t/esm/deprecated/plain_option/and_then_async.js

A toolkit of Nullable/Option/Result type implementation in ECMAScript. Their APIs are inspired by Rust's `Option<T>` and `Result<T, E>`.

import { isNone, unwrapSome } from './option.js';
/**
 *  Returns `None` if the _input_ is `None`,
 *  otherwise calls _transformer_ with the value and returns the result.
 *
 *  XXX:
 *  Some languages call this operation flatmap.
 *  But we don't provide `flatMap()` as alias of this function
 *  to sort with other APIs.
 */
export async function andThenAsyncForOption(input, transformer) {
    if (isNone(input)) {
        return input;
    }
    const inner = unwrapSome(input);
    const result = await transformer(inner);
    return result;
}