Collect into a Result in Rust
Rust interview exercise on Option & Result, difficulty 2 of 3. Solve it in the editor beside a worked example, or cold in Interview mode with the example hidden; the tests run the moment you do.
Write parse_all(items) that parses every string (ignoring surrounding whitespace) as an i32. Return Ok with all the numbers, or the first parse error. An iterator of Results collects into a Result of a Vec.
Each exercise pairs a worked example with a twin problem to solve in a real editor; the tests run the moment you do. Interview mode hides the example: solve it from memory, without the hint or the solution, and it counts as solved cold. Progress is saved in your browser, and in your account if you sign in.