@yaml/yamlscript NPM

YAMLScript

Program in YAML

Synopsis

#!/usr/bin/env ys-0

defn main(name="World"):
  say: "Hello, $name!"

Description

YAMLScript is a functional programming language with a stylized YAML syntax.

YAMLScript can be used for:

Enhancing ordinary YAML files with new functional magics
- Import parts of other YAML files to any node
- String interpolation including function calls
- merge, concat and about any other function you need!
Writing new programs and applications
- Run with ys file.ys
- Or compile to binary executable with ys -C file.ys
Writing reusable shared libraries
- High level code instead of C
- Bindable to almost any programming language

YAMLScript should be a drop-in replacement for your YAML loader!

Most existing YAML files are already valid YAMLScript files. This means that YAMLScript works as a normal YAML loader, but can also evaluate functional expressions if asked to.

Under the hood, YAMLScript code compiles to the Clojure programming language. This makes YAMLScript a complete functional programming language right out of the box.

Even though YAMLScript compiles to Clojure, and Clojure compiles to Java, there is no dependency on Java or the JVM. YAMLScript is compiled to a native shared library (libyamlscript.so) that can be used by any programming language that can load shared libraries.

To see the Clojure code that YAMLScript compiles to, you can use the YAMLScript command line utility, ys, to run:

$ ys --compile file.ys

NodeJS Usage

A YAMLScript file some.ys:

!yamlscript/v0/

=>:
  name =: "World"
  data =: load("some.yaml")
  fruit =: data.food.fruit

num: 123
greet:: "$(data.hello.rand-nth()), $name!"
eat:: fruit.shuffle().first()
drink:: (["Bar"] * 3).join(', ' _).str('!!!')

A YAML file some.yaml:

food:
  fruit:
  - apple
  - banana
  - cherry
  - date

hello:
- Aloha
- Bonjour
- Ciao
- Dzień dobry

NodeJS file ys-load.js:

let fs = require("fs");
let YS = require("@yaml/yamlscript");

let input = fs.readFileSync("some.ys", "utf8");

let ys = new YS();

let data = ys.load(input);

console.log(data);

Run:

$ node ys-load.js | jq
{
  num: 123,
  greet: 'Bonjour, World!',
  eat: 'cherry',
  drink: 'Bar, Bar, Bar!!!'
}

Installation

You can install this module like any other NodeJS module:

$ npm install @yaml/yamlscript

but you will need to have a system install of libyamlscript.so.

One simple way to do that is with:

$ curl https://yamlscript.org/install | bash

Note: The above command will install the latest version of the YAMLScript command line utility, ys, and the shared library, libyamlscript.so, into ~/.local/bin and ~/.local/lib respectively.

See https://github.com/yaml/yamlscript/wiki/Installing-YAMLScript for more info.