Fantasy Promises

This library implements purely functional, monadic promises.

Promise(fork)

Promise is a constructor which takes a fork function. The fork function takes one argument:

fork(resolve)

The resolve callback gets called on a value.

Promise.of(x)

Creates a Promise that contains a successful value.

chain(f)

Returns a new promise that evaluates f when the current promise is successfully fulfilled. f must return a new promise.

map(f)

Returns a new promise that evaluates f on a value and passes it through to the resolve function.

extract()

Executes a promise to get a value.

extend(f)

Returns a new promise that evaluates f over the promise to get a value.

Fantasy Land Compatible