Domain function composition

[diogob]

Purpose

To be able to write domain functions that depend on the result of other domain functions without having to write a bunch of boilerplate.

Technical details

Since every domain function takes 2 arguments and returns a Promise<Result<Output>> we have to define some semantics for our composition:

• The composition always takes the successful data and passes as input for the next function.
• If a function fails we short-circuit the composition and return the failure.
• The environment is constant for the sake of the composition (we always pass the same environment given to the composed function).