@fauna-labs/fql-utilities

This repository contains unofficial patterns, sample code, or tools to help developers build more effectively with Fauna. All Fauna Labs repositories are provided “as-is” and without support. By using this repository or its contents, you agree that this repository may never be officially supported and moved to the Fauna organization.

FQL utilities

This repo contains code for user-defined functions (UDFs) to accomplish common tasks in Fauna. These UDFs are designed to be deployed with Fauna Schema Migrate.

How to use

• npm init -y
• npm install faunadb
• npm install --save-dev @fauna-labs/faunadb-schema-migrate
• npm install --save-dev @fauna-labs/fql-utilities
• npx fauna-schema-migrate init
• Create a file named tail.js in the fauna/resources directory with the following code:

  import { Tail } from '@fauna-labs/fql-utilities';
  
  export default Tail();
  

• npx fauna-schema-migrate generate
• npx fauna-schema-migrate apply

This creates a UDF named Tail() in your database. Tail() accepts one parameter, an Array, and returns a new array consisting of every element except the first. If the array is empty, Tail() returns an empty array.

You can then call the Tail UDF with the following code:

Let(
  {
    array: [0, 1, 2],
    shortArray: Call("Tail", Var("array"))
  },
  Equals(Count(Var("shortArray")), 2) // true
)

Included packages

Collections

• Tail()
• Zip()

Vector math

• CrossProduct()
• DotProduct()