Rust Lang Result Map. The map iterator implements DoubleEndedIterator meaning that you can also map backwards. In the following example because take5 was added after filter it will stop filtering after the fifth successful filter.
In your example there is some logic to the filter so I dont think it simplifies things. As long as there is a memory allocator it is possible to use serde_json without the rest of the Rust standard library. DefIds are used to index results eg.
In Rust I believe the idiomatic way to deal with recoverable errors is to use Result.
Currently map_ok and map_err methods are given for Poll. In the following example because take5 was added after filter it will stop filtering after the fifth successful filter. See its documentation for more. Hundreds of companies around the world are using Rust in production today for fast low-resource cross-platform solutions.