By compose I quite literally mean the compose function.

    const add3 = val => val + 3;
    const multiplyBy10 = val => val * 10;
    const subtract5 = val => val - 5;

    const doABunchOfMath = compose(add3, subtract5, multiplyBy10);

    const ninetyEight = doABunchOfMath(10);

    const optionallyNinetyEight = Some(10).map(doABunchOfMath)

That Dart already provides these extensions feels like they are providing an optional type but through a more complicated mechanism than a simple class

Nowhere in any of the functions I wrote above do I as a user have to worry about handling the case where no number exists, that's handled by the option type and signified by the type (The value in the option may or may not exist) and I can write my functions without ever having to worry about handling that case