Another Maybe monad lib

This is another library that mimicks standard Maybe monad known from many functional languages.

It it supplied with standard API such as: Maybe.of, Maybe#map, Maybe#flatMap. For more info, look at the tests.

Docs

For documentation, look at the tests. All the cases are tested there along with TS typings.

API differences

There is just one interesting thing that might be more useful than other libraries out there. I wanted to be able to have this monad "as an input". This would be useful that I could write some safe transformation at one place:

function FilePickerComponent({
  doSomethingWithTheFile,
}: {
  doSomethingWithTheFile: (file: File) => void;
}) {
  return (
    <input
      type="file"
      onChange={Maybe.asInput((event: ChangeEvent<HTMLInputElement>) =>
        Maybe.fromFirst(Array.from(event.target.files ?? [])).map(
          doSomethingWithTheFile
        )
      )}
    />
  );
}

This enables you to define the Maybe in a callback and you can even prepare this function before and memoize it.

Installation

npm i --save actual-maybe

yarn add actual-maybe

pnpm i --save actual-maybe

bun i --save actual maybe

Testing

Standard script:

npm run test --all

yarn test

bun run test

Contributions

You are free to use this library propose any change in a pull request.

Cheers.